1 /*
2 * Copyright (c) 1994, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.lang;
26
27 import java.io.BufferedInputStream;
28 import java.io.BufferedOutputStream;
29 import java.io.Console;
30 import java.io.FileDescriptor;
31 import java.io.FileInputStream;
32 import java.io.FileOutputStream;
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.OutputStream;
36 import java.io.PrintStream;
37 import java.lang.annotation.Annotation;
38 import java.lang.foreign.MemorySegment;
39 import java.lang.invoke.MethodHandle;
40 import java.lang.invoke.MethodType;
41 import java.lang.invoke.StringConcatFactory;
42 import java.lang.module.ModuleDescriptor;
43 import java.lang.reflect.ClassFileFormatVersion;
44 import java.lang.reflect.Constructor;
45 import java.lang.reflect.Executable;
46 import java.lang.reflect.Method;
47 import java.lang.reflect.Modifier;
48 import java.net.URI;
49 import java.net.URL;
50 import java.nio.channels.Channel;
51 import java.nio.channels.spi.SelectorProvider;
52 import java.nio.charset.CharacterCodingException;
53 import java.nio.charset.Charset;
54 import java.security.AccessControlContext;
55 import java.security.AccessController;
56 import java.security.CodeSource;
57 import java.security.PrivilegedAction;
58 import java.security.ProtectionDomain;
59 import java.util.Collections;
60 import java.util.List;
61 import java.util.Locale;
62 import java.util.Map;
63 import java.util.Objects;
64 import java.util.Properties;
65 import java.util.PropertyPermission;
66 import java.util.ResourceBundle;
67 import java.util.Set;
68 import java.util.WeakHashMap;
69 import java.util.concurrent.Executor;
70 import java.util.function.Supplier;
71 import java.util.concurrent.ConcurrentHashMap;
72 import java.util.stream.Stream;
73
74 import jdk.internal.javac.Restricted;
75 import jdk.internal.loader.NativeLibraries;
76 import jdk.internal.logger.LoggerFinderLoader.TemporaryLoggerFinder;
77 import jdk.internal.misc.Blocker;
78 import jdk.internal.misc.CarrierThreadLocal;
79 import jdk.internal.misc.Unsafe;
80 import jdk.internal.util.StaticProperty;
81 import jdk.internal.module.ModuleBootstrap;
82 import jdk.internal.module.ServicesCatalog;
83 import jdk.internal.reflect.CallerSensitive;
84 import jdk.internal.reflect.Reflection;
85 import jdk.internal.access.JavaLangAccess;
86 import jdk.internal.access.SharedSecrets;
87 import jdk.internal.logger.LoggerFinderLoader;
88 import jdk.internal.logger.LazyLoggers;
89 import jdk.internal.logger.LocalizedLoggerWrapper;
90 import jdk.internal.misc.VM;
91 import jdk.internal.util.SystemProps;
92 import jdk.internal.vm.Continuation;
93 import jdk.internal.vm.ContinuationScope;
94 import jdk.internal.vm.StackableScope;
95 import jdk.internal.vm.ThreadContainer;
96 import jdk.internal.vm.annotation.IntrinsicCandidate;
97 import jdk.internal.vm.annotation.Stable;
98 import sun.nio.fs.DefaultFileSystemProvider;
99 import sun.reflect.annotation.AnnotationType;
100 import sun.nio.ch.Interruptible;
101 import sun.nio.cs.UTF_8;
102 import sun.security.util.SecurityConstants;
103
104 /**
105 * The {@code System} class contains several useful class fields
106 * and methods. It cannot be instantiated.
107 *
108 * Among the facilities provided by the {@code System} class
109 * are standard input, standard output, and error output streams;
110 * access to externally defined properties and environment
111 * variables; a means of loading files and libraries; and a utility
112 * method for quickly copying a portion of an array.
113 *
114 * @since 1.0
115 */
116 public final class System {
117 /* Register the natives via the static initializer.
118 *
119 * The VM will invoke the initPhase1 method to complete the initialization
120 * of this class separate from <clinit>.
121 */
122 private static native void registerNatives();
123 static {
124 registerNatives();
125 }
126
127 /** Don't let anyone instantiate this class */
128 private System() {
129 }
130
131 /**
132 * The "standard" input stream. This stream is already
133 * open and ready to supply input data. Typically this stream
134 * corresponds to keyboard input or another input source specified by
135 * the host environment or user. In case this stream is wrapped
136 * in a {@link java.io.InputStreamReader}, {@link Console#charset()}
137 * should be used for the charset, or consider using
138 * {@link Console#reader()}.
139 *
140 * @see Console#charset()
141 * @see Console#reader()
142 */
143 public static final InputStream in = null;
144
145 /**
146 * The "standard" output stream. This stream is already
147 * open and ready to accept output data. Typically this stream
148 * corresponds to display output or another output destination
149 * specified by the host environment or user. The encoding used
150 * in the conversion from characters to bytes is equivalent to
151 * {@link Console#charset()} if the {@code Console} exists,
152 * <a href="#stdout.encoding">stdout.encoding</a> otherwise.
153 * <p>
154 * For simple stand-alone Java applications, a typical way to write
155 * a line of output data is:
156 * <blockquote><pre>
157 * System.out.println(data)
158 * </pre></blockquote>
159 * <p>
160 * See the {@code println} methods in class {@code PrintStream}.
161 *
162 * @see java.io.PrintStream#println()
163 * @see java.io.PrintStream#println(boolean)
164 * @see java.io.PrintStream#println(char)
165 * @see java.io.PrintStream#println(char[])
166 * @see java.io.PrintStream#println(double)
167 * @see java.io.PrintStream#println(float)
168 * @see java.io.PrintStream#println(int)
169 * @see java.io.PrintStream#println(long)
170 * @see java.io.PrintStream#println(java.lang.Object)
171 * @see java.io.PrintStream#println(java.lang.String)
172 * @see Console#charset()
173 * @see <a href="#stdout.encoding">stdout.encoding</a>
174 */
175 public static final PrintStream out = null;
176
177 /**
178 * The "standard" error output stream. This stream is already
179 * open and ready to accept output data.
180 * <p>
181 * Typically this stream corresponds to display output or another
182 * output destination specified by the host environment or user. By
183 * convention, this output stream is used to display error messages
184 * or other information that should come to the immediate attention
185 * of a user even if the principal output stream, the value of the
186 * variable {@code out}, has been redirected to a file or other
187 * destination that is typically not continuously monitored.
188 * The encoding used in the conversion from characters to bytes is
189 * equivalent to {@link Console#charset()} if the {@code Console}
190 * exists, <a href="#stderr.encoding">stderr.encoding</a> otherwise.
191 *
192 * @see Console#charset()
193 * @see <a href="#stderr.encoding">stderr.encoding</a>
194 */
195 public static final PrintStream err = null;
196
197 // Initial values of System.in and System.err, set in initPhase1().
198 private static @Stable InputStream initialIn;
199 private static @Stable PrintStream initialErr;
200
201 // indicates if a security manager is possible
202 private static final int NEVER = 1;
203 private static final int MAYBE = 2;
204 private static @Stable int allowSecurityManager;
205
206 // current security manager
207 @SuppressWarnings("removal")
208 private static volatile SecurityManager security; // read by VM
209
210 // `sun.jnu.encoding` if it is not supported. Otherwise null.
211 // It is initialized in `initPhase1()` before any charset providers
212 // are initialized.
213 private static String notSupportedJnuEncoding;
214
215 // return true if a security manager is allowed
216 private static boolean allowSecurityManager() {
217 return (allowSecurityManager != NEVER);
218 }
219
220 /**
221 * Reassigns the "standard" input stream.
222 *
223 * First, if there is a security manager, its {@code checkPermission}
224 * method is called with a {@code RuntimePermission("setIO")} permission
225 * to see if it's ok to reassign the "standard" input stream.
226 *
227 * @param in the new standard input stream.
228 *
229 * @throws SecurityException
230 * if a security manager exists and its
231 * {@code checkPermission} method doesn't allow
232 * reassigning of the standard input stream.
233 *
234 * @see SecurityManager#checkPermission
235 * @see java.lang.RuntimePermission
236 *
237 * @since 1.1
238 */
239 public static void setIn(InputStream in) {
240 checkIO();
241 setIn0(in);
242 }
243
244 /**
245 * Reassigns the "standard" output stream.
246 *
247 * First, if there is a security manager, its {@code checkPermission}
248 * method is called with a {@code RuntimePermission("setIO")} permission
249 * to see if it's ok to reassign the "standard" output stream.
250 *
251 * @param out the new standard output stream
252 *
253 * @throws SecurityException
254 * if a security manager exists and its
255 * {@code checkPermission} method doesn't allow
256 * reassigning of the standard output stream.
257 *
258 * @see SecurityManager#checkPermission
259 * @see java.lang.RuntimePermission
260 *
261 * @since 1.1
262 */
263 public static void setOut(PrintStream out) {
264 checkIO();
265 setOut0(out);
266 }
267
268 /**
269 * Reassigns the "standard" error output stream.
270 *
271 * First, if there is a security manager, its {@code checkPermission}
272 * method is called with a {@code RuntimePermission("setIO")} permission
273 * to see if it's ok to reassign the "standard" error output stream.
274 *
275 * @param err the new standard error output stream.
276 *
277 * @throws SecurityException
278 * if a security manager exists and its
279 * {@code checkPermission} method doesn't allow
280 * reassigning of the standard error output stream.
281 *
282 * @see SecurityManager#checkPermission
283 * @see java.lang.RuntimePermission
284 *
285 * @since 1.1
286 */
287 public static void setErr(PrintStream err) {
288 checkIO();
289 setErr0(err);
290 }
291
292 private static volatile Console cons;
293
294 /**
295 * Returns the unique {@link java.io.Console Console} object associated
296 * with the current Java virtual machine, if any.
297 *
298 * @return The system console, if any, otherwise {@code null}.
299 *
300 * @since 1.6
301 */
302 public static Console console() {
303 Console c;
304 if ((c = cons) == null) {
305 synchronized (System.class) {
306 if ((c = cons) == null) {
307 cons = c = SharedSecrets.getJavaIOAccess().console();
308 }
309 }
310 }
311 return c;
312 }
313
314 /**
315 * Returns the channel inherited from the entity that created this
316 * Java virtual machine.
317 *
318 * This method returns the channel obtained by invoking the
319 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
320 * inheritedChannel} method of the system-wide default
321 * {@link java.nio.channels.spi.SelectorProvider} object.
322 *
323 * <p> In addition to the network-oriented channels described in
324 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
325 * inheritedChannel}, this method may return other kinds of
326 * channels in the future.
327 *
328 * @return The inherited channel, if any, otherwise {@code null}.
329 *
330 * @throws IOException
331 * If an I/O error occurs
332 *
333 * @throws SecurityException
334 * If a security manager is present and it does not
335 * permit access to the channel.
336 *
337 * @since 1.5
338 */
339 public static Channel inheritedChannel() throws IOException {
340 return SelectorProvider.provider().inheritedChannel();
341 }
342
343 private static void checkIO() {
344 @SuppressWarnings("removal")
345 SecurityManager sm = getSecurityManager();
346 if (sm != null) {
347 sm.checkPermission(new RuntimePermission("setIO"));
348 }
349 }
350
351 private static native void setIn0(InputStream in);
352 private static native void setOut0(PrintStream out);
353 private static native void setErr0(PrintStream err);
354
355 private static class CallersHolder {
356 // Remember callers of setSecurityManager() here so that warning
357 // is only printed once for each different caller
358 static final Map<Class<?>, Boolean> callers
359 = Collections.synchronizedMap(new WeakHashMap<>());
360 }
361
362 static URL codeSource(Class<?> clazz) {
363 PrivilegedAction<ProtectionDomain> pa = clazz::getProtectionDomain;
364 @SuppressWarnings("removal")
365 CodeSource cs = AccessController.doPrivileged(pa).getCodeSource();
366 return (cs != null) ? cs.getLocation() : null;
367 }
368
369 /**
370 * Sets the system-wide security manager.
371 *
372 * If there is a security manager already installed, this method first
373 * calls the security manager's {@code checkPermission} method
374 * with a {@code RuntimePermission("setSecurityManager")}
375 * permission to ensure it's ok to replace the existing
376 * security manager.
377 * This may result in throwing a {@code SecurityException}.
378 *
379 * <p> Otherwise, the argument is established as the current
380 * security manager. If the argument is {@code null} and no
381 * security manager has been established, then no action is taken and
382 * the method simply returns.
383 *
384 * @implNote In the JDK implementation, if the Java virtual machine is
385 * started with the system property {@code java.security.manager} not set or set to
386 * the special token "{@code disallow}" then the {@code setSecurityManager}
387 * method cannot be used to set a security manager. See the following
388 * <a href="SecurityManager.html#set-security-manager">section of the
389 * {@code SecurityManager} class specification</a> for more details.
390 *
391 * @param sm the security manager or {@code null}
392 * @throws SecurityException
393 * if the security manager has already been set and its {@code
394 * checkPermission} method doesn't allow it to be replaced
395 * @throws UnsupportedOperationException
396 * if {@code sm} is non-null and a security manager is not allowed
397 * to be set dynamically
398 * @see #getSecurityManager
399 * @see SecurityManager#checkPermission
400 * @see java.lang.RuntimePermission
401 * @deprecated This method is only useful in conjunction with
402 * {@linkplain SecurityManager the Security Manager}, which is
403 * deprecated and subject to removal in a future release.
404 * Consequently, this method is also deprecated and subject to
405 * removal. There is no replacement for the Security Manager or this
406 * method.
407 */
408 @Deprecated(since="17", forRemoval=true)
409 @CallerSensitive
410 public static void setSecurityManager(@SuppressWarnings("removal") SecurityManager sm) {
411 if (allowSecurityManager()) {
412 var callerClass = Reflection.getCallerClass();
413 if (CallersHolder.callers.putIfAbsent(callerClass, true) == null) {
414 URL url = codeSource(callerClass);
415 final String source;
416 if (url == null) {
417 source = callerClass.getName();
418 } else {
419 source = callerClass.getName() + " (" + url + ")";
420 }
421 initialErr.printf("""
422 WARNING: A terminally deprecated method in java.lang.System has been called
423 WARNING: System::setSecurityManager has been called by %s
424 WARNING: Please consider reporting this to the maintainers of %s
425 WARNING: System::setSecurityManager will be removed in a future release
426 """, source, callerClass.getName());
427 }
428 implSetSecurityManager(sm);
429 } else {
430 // security manager not allowed
431 if (sm != null) {
432 throw new UnsupportedOperationException(
433 "The Security Manager is deprecated and will be removed in a future release");
434 }
435 }
436 }
437
438 private static void implSetSecurityManager(@SuppressWarnings("removal") SecurityManager sm) {
439 if (security == null) {
440 // ensure image reader is initialized
441 Object.class.getResource("java/lang/ANY");
442 // ensure the default file system is initialized
443 DefaultFileSystemProvider.theFileSystem();
444 }
445 if (sm != null) {
446 try {
447 // pre-populates the SecurityManager.packageAccess cache
448 // to avoid recursive permission checking issues with custom
449 // SecurityManager implementations
450 sm.checkPackageAccess("java.lang");
451 } catch (Exception e) {
452 // no-op
453 }
454 }
455 setSecurityManager0(sm);
456 }
457
458 @SuppressWarnings("removal")
459 private static synchronized
460 void setSecurityManager0(final SecurityManager s) {
461 SecurityManager sm = getSecurityManager();
462 if (sm != null) {
463 // ask the currently installed security manager if we
464 // can replace it.
465 sm.checkPermission(new RuntimePermission("setSecurityManager"));
466 }
467
468 if ((s != null) && (s.getClass().getClassLoader() != null)) {
469 // New security manager class is not on bootstrap classpath.
470 // Force policy to get initialized before we install the new
471 // security manager, in order to prevent infinite loops when
472 // trying to initialize the policy (which usually involves
473 // accessing some security and/or system properties, which in turn
474 // calls the installed security manager's checkPermission method
475 // which will loop infinitely if there is a non-system class
476 // (in this case: the new security manager class) on the stack).
477 AccessController.doPrivileged(new PrivilegedAction<>() {
478 public Object run() {
479 s.getClass().getProtectionDomain().implies
480 (SecurityConstants.ALL_PERMISSION);
481 return null;
482 }
483 });
484 }
485
486 security = s;
487 }
488
489 /**
490 * Gets the system-wide security manager.
491 *
492 * @return if a security manager has already been established for the
493 * current application, then that security manager is returned;
494 * otherwise, {@code null} is returned.
495 * @see #setSecurityManager
496 * @deprecated This method is only useful in conjunction with
497 * {@linkplain SecurityManager the Security Manager}, which is
498 * deprecated and subject to removal in a future release.
499 * Consequently, this method is also deprecated and subject to
500 * removal. There is no replacement for the Security Manager or this
501 * method.
502 */
503 @SuppressWarnings("removal")
504 @Deprecated(since="17", forRemoval=true)
505 public static SecurityManager getSecurityManager() {
506 if (allowSecurityManager()) {
507 return security;
508 } else {
509 return null;
510 }
511 }
512
513 /**
514 * Returns the current time in milliseconds. Note that
515 * while the unit of time of the return value is a millisecond,
516 * the granularity of the value depends on the underlying
517 * operating system and may be larger. For example, many
518 * operating systems measure time in units of tens of
519 * milliseconds.
520 *
521 * <p> See the description of the class {@code Date} for
522 * a discussion of slight discrepancies that may arise between
523 * "computer time" and coordinated universal time (UTC).
524 *
525 * @return the difference, measured in milliseconds, between
526 * the current time and midnight, January 1, 1970 UTC.
527 * @see java.util.Date
528 */
529 @IntrinsicCandidate
530 public static native long currentTimeMillis();
531
532 /**
533 * Returns the current value of the running Java Virtual Machine's
534 * high-resolution time source, in nanoseconds.
535 *
536 * This method can only be used to measure elapsed time and is
537 * not related to any other notion of system or wall-clock time.
538 * The value returned represents nanoseconds since some fixed but
539 * arbitrary <i>origin</i> time (perhaps in the future, so values
540 * may be negative). The same origin is used by all invocations of
541 * this method in an instance of a Java virtual machine; other
542 * virtual machine instances are likely to use a different origin.
543 *
544 * <p>This method provides nanosecond precision, but not necessarily
545 * nanosecond resolution (that is, how frequently the value changes)
546 * - no guarantees are made except that the resolution is at least as
547 * good as that of {@link #currentTimeMillis()}.
548 *
549 * <p>Differences in successive calls that span greater than
550 * approximately 292 years (2<sup>63</sup> nanoseconds) will not
551 * correctly compute elapsed time due to numerical overflow.
552 *
553 * <p>The values returned by this method become meaningful only when
554 * the difference between two such values, obtained within the same
555 * instance of a Java virtual machine, is computed.
556 *
557 * <p>For example, to measure how long some code takes to execute:
558 * <pre> {@code
559 * long startTime = System.nanoTime();
560 * // ... the code being measured ...
561 * long elapsedNanos = System.nanoTime() - startTime;}</pre>
562 *
563 * <p>To compare elapsed time against a timeout, use <pre> {@code
564 * if (System.nanoTime() - startTime >= timeoutNanos) ...}</pre>
565 * instead of <pre> {@code
566 * if (System.nanoTime() >= startTime + timeoutNanos) ...}</pre>
567 * because of the possibility of numerical overflow.
568 *
569 * @return the current value of the running Java Virtual Machine's
570 * high-resolution time source, in nanoseconds
571 * @since 1.5
572 */
573 @IntrinsicCandidate
574 public static native long nanoTime();
575
576 /**
577 * Copies an array from the specified source array, beginning at the
578 * specified position, to the specified position of the destination array.
579 * A subsequence of array components are copied from the source
580 * array referenced by {@code src} to the destination array
581 * referenced by {@code dest}. The number of components copied is
582 * equal to the {@code length} argument. The components at
583 * positions {@code srcPos} through
584 * {@code srcPos+length-1} in the source array are copied into
585 * positions {@code destPos} through
586 * {@code destPos+length-1}, respectively, of the destination
587 * array.
588 * <p>
589 * If the {@code src} and {@code dest} arguments refer to the
590 * same array object, then the copying is performed as if the
591 * components at positions {@code srcPos} through
592 * {@code srcPos+length-1} were first copied to a temporary
593 * array with {@code length} components and then the contents of
594 * the temporary array were copied into positions
595 * {@code destPos} through {@code destPos+length-1} of the
596 * destination array.
597 * <p>
598 * If {@code dest} is {@code null}, then a
599 * {@code NullPointerException} is thrown.
600 * <p>
601 * If {@code src} is {@code null}, then a
602 * {@code NullPointerException} is thrown and the destination
603 * array is not modified.
604 * <p>
605 * Otherwise, if any of the following is true, an
606 * {@code ArrayStoreException} is thrown and the destination is
607 * not modified:
608 * <ul>
609 * <li>The {@code src} argument refers to an object that is not an
610 * array.
611 * <li>The {@code dest} argument refers to an object that is not an
612 * array.
613 * <li>The {@code src} argument and {@code dest} argument refer
614 * to arrays whose component types are different primitive types.
615 * <li>The {@code src} argument refers to an array with a primitive
616 * component type and the {@code dest} argument refers to an array
617 * with a reference component type.
618 * <li>The {@code src} argument refers to an array with a reference
619 * component type and the {@code dest} argument refers to an array
620 * with a primitive component type.
621 * </ul>
622 * <p>
623 * Otherwise, if any of the following is true, an
624 * {@code IndexOutOfBoundsException} is
625 * thrown and the destination is not modified:
626 * <ul>
627 * <li>The {@code srcPos} argument is negative.
628 * <li>The {@code destPos} argument is negative.
629 * <li>The {@code length} argument is negative.
630 * <li>{@code srcPos+length} is greater than
631 * {@code src.length}, the length of the source array.
632 * <li>{@code destPos+length} is greater than
633 * {@code dest.length}, the length of the destination array.
634 * </ul>
635 * <p>
636 * Otherwise, if any actual component of the source array from
637 * position {@code srcPos} through
638 * {@code srcPos+length-1} cannot be converted to the component
639 * type of the destination array by assignment conversion, an
640 * {@code ArrayStoreException} is thrown. In this case, let
641 * <b><i>k</i></b> be the smallest nonnegative integer less than
642 * length such that {@code src[srcPos+}<i>k</i>{@code ]}
643 * cannot be converted to the component type of the destination
644 * array; when the exception is thrown, source array components from
645 * positions {@code srcPos} through
646 * {@code srcPos+}<i>k</i>{@code -1}
647 * will already have been copied to destination array positions
648 * {@code destPos} through
649 * {@code destPos+}<i>k</I>{@code -1} and no other
650 * positions of the destination array will have been modified.
651 * (Because of the restrictions already itemized, this
652 * paragraph effectively applies only to the situation where both
653 * arrays have component types that are reference types.)
654 *
655 * @param src the source array.
656 * @param srcPos starting position in the source array.
657 * @param dest the destination array.
658 * @param destPos starting position in the destination data.
659 * @param length the number of array elements to be copied.
660 * @throws IndexOutOfBoundsException if copying would cause
661 * access of data outside array bounds.
662 * @throws ArrayStoreException if an element in the {@code src}
663 * array could not be stored into the {@code dest} array
664 * because of a type mismatch.
665 * @throws NullPointerException if either {@code src} or
666 * {@code dest} is {@code null}.
667 */
668 @IntrinsicCandidate
669 public static native void arraycopy(Object src, int srcPos,
670 Object dest, int destPos,
671 int length);
672
673 /**
674 * Returns the same hash code for the given object as
675 * would be returned by the default method hashCode(),
676 * whether or not the given object's class overrides
677 * hashCode().
678 * The hash code for the null reference is zero.
679 *
680 * @param x object for which the hashCode is to be calculated
681 * @return the hashCode
682 * @since 1.1
683 * @see Object#hashCode
684 * @see java.util.Objects#hashCode(Object)
685 */
686 @IntrinsicCandidate
687 public static native int identityHashCode(Object x);
688
689 /**
690 * System properties.
691 *
692 * See {@linkplain #getProperties getProperties} for details.
693 */
694 private static Properties props;
695
696 /**
697 * Determines the current system properties.
698 *
699 * First, if there is a security manager, its
700 * {@code checkPropertiesAccess} method is called with no
701 * arguments. This may result in a security exception.
702 * <p>
703 * The current set of system properties for use by the
704 * {@link #getProperty(String)} method is returned as a
705 * {@code Properties} object. If there is no current set of
706 * system properties, a set of system properties is first created and
707 * initialized. This set of system properties includes a value
708 * for each of the following keys unless the description of the associated
709 * value indicates that the value is optional.
710 * <table class="striped" style="text-align:left">
711 * <caption style="display:none">Shows property keys and associated values</caption>
712 * <thead>
713 * <tr><th scope="col">Key</th>
714 * <th scope="col">Description of Associated Value</th></tr>
715 * </thead>
716 * <tbody>
717 * <tr><th scope="row">{@systemProperty java.version}</th>
718 * <td>Java Runtime Environment version, which may be interpreted
719 * as a {@link Runtime.Version}</td></tr>
720 * <tr><th scope="row">{@systemProperty java.version.date}</th>
721 * <td>Java Runtime Environment version date, in ISO-8601 YYYY-MM-DD
722 * format, which may be interpreted as a {@link
723 * java.time.LocalDate}</td></tr>
724 * <tr><th scope="row">{@systemProperty java.vendor}</th>
725 * <td>Java Runtime Environment vendor</td></tr>
726 * <tr><th scope="row">{@systemProperty java.vendor.url}</th>
727 * <td>Java vendor URL</td></tr>
728 * <tr><th scope="row">{@systemProperty java.vendor.version}</th>
729 * <td>Java vendor version <em>(optional)</em> </td></tr>
730 * <tr><th scope="row">{@systemProperty java.home}</th>
731 * <td>Java installation directory</td></tr>
732 * <tr><th scope="row">{@systemProperty java.vm.specification.version}</th>
733 * <td>Java Virtual Machine specification version, whose value is the
734 * {@linkplain Runtime.Version#feature feature} element of the
735 * {@linkplain Runtime#version() runtime version}</td></tr>
736 * <tr><th scope="row">{@systemProperty java.vm.specification.vendor}</th>
737 * <td>Java Virtual Machine specification vendor</td></tr>
738 * <tr><th scope="row">{@systemProperty java.vm.specification.name}</th>
739 * <td>Java Virtual Machine specification name</td></tr>
740 * <tr><th scope="row">{@systemProperty java.vm.version}</th>
741 * <td>Java Virtual Machine implementation version which may be
742 * interpreted as a {@link Runtime.Version}</td></tr>
743 * <tr><th scope="row">{@systemProperty java.vm.vendor}</th>
744 * <td>Java Virtual Machine implementation vendor</td></tr>
745 * <tr><th scope="row">{@systemProperty java.vm.name}</th>
746 * <td>Java Virtual Machine implementation name</td></tr>
747 * <tr><th scope="row">{@systemProperty java.specification.version}</th>
748 * <td>Java Runtime Environment specification version, whose value is
749 * the {@linkplain Runtime.Version#feature feature} element of the
750 * {@linkplain Runtime#version() runtime version}</td></tr>
751 * <tr><th scope="row">{@systemProperty java.specification.maintenance.version}</th>
752 * <td>Java Runtime Environment specification maintenance version,
753 * may be interpreted as a positive integer <em>(optional, see below)</em></td></tr>
754 * <tr><th scope="row">{@systemProperty java.specification.vendor}</th>
755 * <td>Java Runtime Environment specification vendor</td></tr>
756 * <tr><th scope="row">{@systemProperty java.specification.name}</th>
757 * <td>Java Runtime Environment specification name</td></tr>
758 * <tr><th scope="row">{@systemProperty java.class.version}</th>
759 * <td>{@linkplain java.lang.reflect.ClassFileFormatVersion#latest() Latest}
760 * Java class file format version recognized by the Java runtime as {@code "MAJOR.MINOR"}
761 * where {@link java.lang.reflect.ClassFileFormatVersion#major() MAJOR} and {@code MINOR}
762 * are both formatted as decimal integers</td></tr>
763 * <tr><th scope="row">{@systemProperty java.class.path}</th>
764 * <td>Java class path (refer to
765 * {@link ClassLoader#getSystemClassLoader()} for details)</td></tr>
766 * <tr><th scope="row">{@systemProperty java.library.path}</th>
767 * <td>List of paths to search when loading libraries</td></tr>
768 * <tr><th scope="row">{@systemProperty java.io.tmpdir}</th>
769 * <td>Default temp file path</td></tr>
770 * <tr><th scope="row">{@systemProperty os.name}</th>
771 * <td>Operating system name</td></tr>
772 * <tr><th scope="row">{@systemProperty os.arch}</th>
773 * <td>Operating system architecture</td></tr>
774 * <tr><th scope="row">{@systemProperty os.version}</th>
775 * <td>Operating system version</td></tr>
776 * <tr><th scope="row">{@systemProperty file.separator}</th>
777 * <td>File separator ("/" on UNIX)</td></tr>
778 * <tr><th scope="row">{@systemProperty path.separator}</th>
779 * <td>Path separator (":" on UNIX)</td></tr>
780 * <tr><th scope="row">{@systemProperty line.separator}</th>
781 * <td>Line separator ("\n" on UNIX)</td></tr>
782 * <tr><th scope="row">{@systemProperty user.name}</th>
783 * <td>User's account name</td></tr>
784 * <tr><th scope="row">{@systemProperty user.home}</th>
785 * <td>User's home directory</td></tr>
786 * <tr><th scope="row">{@systemProperty user.dir}</th>
787 * <td>User's current working directory</td></tr>
788 * <tr><th scope="row">{@systemProperty native.encoding}</th>
789 * <td>Character encoding name derived from the host environment and/or
790 * the user's settings. Setting this system property has no effect.</td></tr>
791 * <tr><th scope="row">{@systemProperty stdout.encoding}</th>
792 * <td>Character encoding name for {@link System#out System.out}.
793 * The Java runtime can be started with the system property set to {@code UTF-8},
794 * starting it with the property set to another value leads to undefined behavior.
795 * <tr><th scope="row">{@systemProperty stderr.encoding}</th>
796 * <td>Character encoding name for {@link System#err System.err}.
797 * The Java runtime can be started with the system property set to {@code UTF-8},
798 * starting it with the property set to another value leads to undefined behavior.
799 * </tbody>
800 * </table>
801 * <p>
802 * The {@code java.specification.maintenance.version} property is
803 * defined if the specification implemented by this runtime at the
804 * time of its construction had undergone a <a
805 * href="https://jcp.org/en/procedures/jcp2#3.6.4">maintenance
806 * release</a>. When defined, its value identifies that
807 * maintenance release. To indicate the first maintenance release
808 * this property will have the value {@code "1"}, to indicate the
809 * second maintenance release this property will have the value
810 * {@code "2"}, and so on.
811 * <p>
812 * Multiple paths in a system property value are separated by the path
813 * separator character of the platform.
814 * <p>
815 * Note that even if the security manager does not permit the
816 * {@code getProperties} operation, it may choose to permit the
817 * {@link #getProperty(String)} operation.
818 * <p>
819 * Additional locale-related system properties defined by the
820 * {@link Locale##default_locale Default Locale} section in the {@code Locale}
821 * class description may also be obtained with this method.
822 *
823 * @apiNote
824 * <strong>Changing a standard system property may have unpredictable results
825 * unless otherwise specified.</strong>
826 * Property values may be cached during initialization or on first use.
827 * Setting a standard property after initialization using {@link #getProperties()},
828 * {@link #setProperties(Properties)}, {@link #setProperty(String, String)}, or
829 * {@link #clearProperty(String)} may not have the desired effect.
830 *
831 * @implNote
832 * In addition to the standard system properties, the system
833 * properties may include the following keys:
834 * <table class="striped">
835 * <caption style="display:none">Shows property keys and associated values</caption>
836 * <thead>
837 * <tr><th scope="col">Key</th>
838 * <th scope="col">Description of Associated Value</th></tr>
839 * </thead>
840 * <tbody>
841 * <tr><th scope="row">{@systemProperty jdk.module.path}</th>
842 * <td>The application module path</td></tr>
843 * <tr><th scope="row">{@systemProperty jdk.module.upgrade.path}</th>
844 * <td>The upgrade module path</td></tr>
845 * <tr><th scope="row">{@systemProperty jdk.module.main}</th>
846 * <td>The module name of the initial/main module</td></tr>
847 * <tr><th scope="row">{@systemProperty jdk.module.main.class}</th>
848 * <td>The main class name of the initial module</td></tr>
849 * <tr><th scope="row">{@systemProperty file.encoding}</th>
850 * <td>The name of the default charset, defaults to {@code UTF-8}.
851 * The property may be set on the command line to the value
852 * {@code UTF-8} or {@code COMPAT}. If set on the command line to
853 * the value {@code COMPAT} then the value is replaced with the
854 * value of the {@code native.encoding} property during startup.
855 * Setting the property to a value other than {@code UTF-8} or
856 * {@code COMPAT} leads to unspecified behavior.
857 * </td></tr>
858 * </tbody>
859 * </table>
860 *
861 * @return the system properties
862 * @throws SecurityException if a security manager exists and its
863 * {@code checkPropertiesAccess} method doesn't allow access
864 * to the system properties.
865 * @see #setProperties
866 * @see java.lang.SecurityException
867 * @see java.lang.SecurityManager#checkPropertiesAccess()
868 * @see java.util.Properties
869 */
870 public static Properties getProperties() {
871 @SuppressWarnings("removal")
872 SecurityManager sm = getSecurityManager();
873 if (sm != null) {
874 sm.checkPropertiesAccess();
875 }
876
877 return props;
878 }
879
880 /**
881 * Returns the system-dependent line separator string. It always
882 * returns the same value - the initial value of the {@linkplain
883 * #getProperty(String) system property} {@code line.separator}.
884 *
885 * <p>On UNIX systems, it returns {@code "\n"}; on Microsoft
886 * Windows systems it returns {@code "\r\n"}.
887 *
888 * @return the system-dependent line separator string
889 * @since 1.7
890 */
891 public static String lineSeparator() {
892 return lineSeparator;
893 }
894
895 private static String lineSeparator;
896
897 /**
898 * Sets the system properties to the {@code Properties} argument.
899 *
900 * First, if there is a security manager, its
901 * {@code checkPropertiesAccess} method is called with no
902 * arguments. This may result in a security exception.
903 * <p>
904 * The argument becomes the current set of system properties for use
905 * by the {@link #getProperty(String)} method. If the argument is
906 * {@code null}, then the current set of system properties is
907 * forgotten.
908 *
909 * @apiNote
910 * <strong>Changing a standard system property may have unpredictable results
911 * unless otherwise specified</strong>.
912 * See {@linkplain #getProperties getProperties} for details.
913 *
914 * @param props the new system properties.
915 * @throws SecurityException if a security manager exists and its
916 * {@code checkPropertiesAccess} method doesn't allow access
917 * to the system properties.
918 * @see #getProperties
919 * @see java.util.Properties
920 * @see java.lang.SecurityException
921 * @see java.lang.SecurityManager#checkPropertiesAccess()
922 */
923 public static void setProperties(Properties props) {
924 @SuppressWarnings("removal")
925 SecurityManager sm = getSecurityManager();
926 if (sm != null) {
927 sm.checkPropertiesAccess();
928 }
929
930 if (props == null) {
931 Map<String, String> tempProps = SystemProps.initProperties();
932 VersionProps.init(tempProps);
933 props = createProperties(tempProps);
934 }
935 System.props = props;
936 }
937
938 /**
939 * Gets the system property indicated by the specified key.
940 *
941 * First, if there is a security manager, its
942 * {@code checkPropertyAccess} method is called with the key as
943 * its argument. This may result in a SecurityException.
944 * <p>
945 * If there is no current set of system properties, a set of system
946 * properties is first created and initialized in the same manner as
947 * for the {@code getProperties} method.
948 *
949 * @apiNote
950 * <strong>Changing a standard system property may have unpredictable results
951 * unless otherwise specified</strong>.
952 * See {@linkplain #getProperties getProperties} for details.
953 *
954 * @param key the name of the system property.
955 * @return the string value of the system property,
956 * or {@code null} if there is no property with that key.
957 *
958 * @throws SecurityException if a security manager exists and its
959 * {@code checkPropertyAccess} method doesn't allow
960 * access to the specified system property.
961 * @throws NullPointerException if {@code key} is {@code null}.
962 * @throws IllegalArgumentException if {@code key} is empty.
963 * @see #setProperty
964 * @see java.lang.SecurityException
965 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
966 * @see java.lang.System#getProperties()
967 */
968 public static String getProperty(String key) {
969 checkKey(key);
970 @SuppressWarnings("removal")
971 SecurityManager sm = getSecurityManager();
972 if (sm != null) {
973 sm.checkPropertyAccess(key);
974 }
975
976 return props.getProperty(key);
977 }
978
979 /**
980 * Gets the system property indicated by the specified key.
981 *
982 * First, if there is a security manager, its
983 * {@code checkPropertyAccess} method is called with the
984 * {@code key} as its argument.
985 * <p>
986 * If there is no current set of system properties, a set of system
987 * properties is first created and initialized in the same manner as
988 * for the {@code getProperties} method.
989 *
990 * @param key the name of the system property.
991 * @param def a default value.
992 * @return the string value of the system property,
993 * or the default value if there is no property with that key.
994 *
995 * @throws SecurityException if a security manager exists and its
996 * {@code checkPropertyAccess} method doesn't allow
997 * access to the specified system property.
998 * @throws NullPointerException if {@code key} is {@code null}.
999 * @throws IllegalArgumentException if {@code key} is empty.
1000 * @see #setProperty
1001 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
1002 * @see java.lang.System#getProperties()
1003 */
1004 public static String getProperty(String key, String def) {
1005 checkKey(key);
1006 @SuppressWarnings("removal")
1007 SecurityManager sm = getSecurityManager();
1008 if (sm != null) {
1009 sm.checkPropertyAccess(key);
1010 }
1011
1012 return props.getProperty(key, def);
1013 }
1014
1015 /**
1016 * Sets the system property indicated by the specified key.
1017 *
1018 * First, if a security manager exists, its
1019 * {@code SecurityManager.checkPermission} method
1020 * is called with a {@code PropertyPermission(key, "write")}
1021 * permission. This may result in a SecurityException being thrown.
1022 * If no exception is thrown, the specified property is set to the given
1023 * value.
1024 *
1025 * @apiNote
1026 * <strong>Changing a standard system property may have unpredictable results
1027 * unless otherwise specified</strong>.
1028 * See {@linkplain #getProperties getProperties} for details.
1029 *
1030 * @param key the name of the system property.
1031 * @param value the value of the system property.
1032 * @return the previous value of the system property,
1033 * or {@code null} if it did not have one.
1034 *
1035 * @throws SecurityException if a security manager exists and its
1036 * {@code checkPermission} method doesn't allow
1037 * setting of the specified property.
1038 * @throws NullPointerException if {@code key} or
1039 * {@code value} is {@code null}.
1040 * @throws IllegalArgumentException if {@code key} is empty.
1041 * @see #getProperty
1042 * @see java.lang.System#getProperty(java.lang.String)
1043 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1044 * @see java.util.PropertyPermission
1045 * @see SecurityManager#checkPermission
1046 * @since 1.2
1047 */
1048 public static String setProperty(String key, String value) {
1049 checkKey(key);
1050 @SuppressWarnings("removal")
1051 SecurityManager sm = getSecurityManager();
1052 if (sm != null) {
1053 sm.checkPermission(new PropertyPermission(key,
1054 SecurityConstants.PROPERTY_WRITE_ACTION));
1055 }
1056
1057 return (String) props.setProperty(key, value);
1058 }
1059
1060 /**
1061 * Removes the system property indicated by the specified key.
1062 *
1063 * First, if a security manager exists, its
1064 * {@code SecurityManager.checkPermission} method
1065 * is called with a {@code PropertyPermission(key, "write")}
1066 * permission. This may result in a SecurityException being thrown.
1067 * If no exception is thrown, the specified property is removed.
1068 *
1069 * @apiNote
1070 * <strong>Changing a standard system property may have unpredictable results
1071 * unless otherwise specified</strong>.
1072 * See {@linkplain #getProperties getProperties} method for details.
1073 *
1074 * @param key the name of the system property to be removed.
1075 * @return the previous string value of the system property,
1076 * or {@code null} if there was no property with that key.
1077 *
1078 * @throws SecurityException if a security manager exists and its
1079 * {@code checkPropertyAccess} method doesn't allow
1080 * access to the specified system property.
1081 * @throws NullPointerException if {@code key} is {@code null}.
1082 * @throws IllegalArgumentException if {@code key} is empty.
1083 * @see #getProperty
1084 * @see #setProperty
1085 * @see java.util.Properties
1086 * @see java.lang.SecurityException
1087 * @see java.lang.SecurityManager#checkPropertiesAccess()
1088 * @since 1.5
1089 */
1090 public static String clearProperty(String key) {
1091 checkKey(key);
1092 @SuppressWarnings("removal")
1093 SecurityManager sm = getSecurityManager();
1094 if (sm != null) {
1095 sm.checkPermission(new PropertyPermission(key, "write"));
1096 }
1097
1098 return (String) props.remove(key);
1099 }
1100
1101 private static void checkKey(String key) {
1102 if (key == null) {
1103 throw new NullPointerException("key can't be null");
1104 }
1105 if (key.isEmpty()) {
1106 throw new IllegalArgumentException("key can't be empty");
1107 }
1108 }
1109
1110 /**
1111 * Gets the value of the specified environment variable. An
1112 * environment variable is a system-dependent external named
1113 * value.
1114 *
1115 * <p>If a security manager exists, its
1116 * {@link SecurityManager#checkPermission checkPermission}
1117 * method is called with a
1118 * {@link RuntimePermission RuntimePermission("getenv."+name)}
1119 * permission. This may result in a {@link SecurityException}
1120 * being thrown. If no exception is thrown the value of the
1121 * variable {@code name} is returned.
1122 *
1123 * <p><a id="EnvironmentVSSystemProperties"><i>System
1124 * properties</i> and <i>environment variables</i></a> are both
1125 * conceptually mappings between names and values. Both
1126 * mechanisms can be used to pass user-defined information to a
1127 * Java process. Environment variables have a more global effect,
1128 * because they are visible to all descendants of the process
1129 * which defines them, not just the immediate Java subprocess.
1130 * They can have subtly different semantics, such as case
1131 * insensitivity, on different operating systems. For these
1132 * reasons, environment variables are more likely to have
1133 * unintended side effects. It is best to use system properties
1134 * where possible. Environment variables should be used when a
1135 * global effect is desired, or when an external system interface
1136 * requires an environment variable (such as {@code PATH}).
1137 *
1138 * <p>On UNIX systems the alphabetic case of {@code name} is
1139 * typically significant, while on Microsoft Windows systems it is
1140 * typically not. For example, the expression
1141 * {@code System.getenv("FOO").equals(System.getenv("foo"))}
1142 * is likely to be true on Microsoft Windows.
1143 *
1144 * @param name the name of the environment variable
1145 * @return the string value of the variable, or {@code null}
1146 * if the variable is not defined in the system environment
1147 * @throws NullPointerException if {@code name} is {@code null}
1148 * @throws SecurityException
1149 * if a security manager exists and its
1150 * {@link SecurityManager#checkPermission checkPermission}
1151 * method doesn't allow access to the environment variable
1152 * {@code name}
1153 * @see #getenv()
1154 * @see ProcessBuilder#environment()
1155 */
1156 public static String getenv(String name) {
1157 @SuppressWarnings("removal")
1158 SecurityManager sm = getSecurityManager();
1159 if (sm != null) {
1160 sm.checkPermission(new RuntimePermission("getenv."+name));
1161 }
1162
1163 return ProcessEnvironment.getenv(name);
1164 }
1165
1166
1167 /**
1168 * Returns an unmodifiable string map view of the current system environment.
1169 * The environment is a system-dependent mapping from names to
1170 * values which is passed from parent to child processes.
1171 *
1172 * <p>If the system does not support environment variables, an
1173 * empty map is returned.
1174 *
1175 * <p>The returned map will never contain null keys or values.
1176 * Attempting to query the presence of a null key or value will
1177 * throw a {@link NullPointerException}. Attempting to query
1178 * the presence of a key or value which is not of type
1179 * {@link String} will throw a {@link ClassCastException}.
1180 *
1181 * <p>The returned map and its collection views may not obey the
1182 * general contract of the {@link Object#equals} and
1183 * {@link Object#hashCode} methods.
1184 *
1185 * <p>The returned map is typically case-sensitive on all platforms.
1186 *
1187 * <p>If a security manager exists, its
1188 * {@link SecurityManager#checkPermission checkPermission}
1189 * method is called with a
1190 * {@link RuntimePermission RuntimePermission("getenv.*")} permission.
1191 * This may result in a {@link SecurityException} being thrown.
1192 *
1193 * <p>When passing information to a Java subprocess,
1194 * <a href=#EnvironmentVSSystemProperties>system properties</a>
1195 * are generally preferred over environment variables.
1196 *
1197 * @return the environment as a map of variable names to values
1198 * @throws SecurityException
1199 * if a security manager exists and its
1200 * {@link SecurityManager#checkPermission checkPermission}
1201 * method doesn't allow access to the process environment
1202 * @see #getenv(String)
1203 * @see ProcessBuilder#environment()
1204 * @since 1.5
1205 */
1206 public static java.util.Map<String,String> getenv() {
1207 @SuppressWarnings("removal")
1208 SecurityManager sm = getSecurityManager();
1209 if (sm != null) {
1210 sm.checkPermission(new RuntimePermission("getenv.*"));
1211 }
1212
1213 return ProcessEnvironment.getenv();
1214 }
1215
1216 /**
1217 * {@code System.Logger} instances log messages that will be
1218 * routed to the underlying logging framework the {@link System.LoggerFinder
1219 * LoggerFinder} uses.
1220 *
1221 * {@code System.Logger} instances are typically obtained from
1222 * the {@link java.lang.System System} class, by calling
1223 * {@link java.lang.System#getLogger(java.lang.String) System.getLogger(loggerName)}
1224 * or {@link java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
1225 * System.getLogger(loggerName, bundle)}.
1226 *
1227 * @see java.lang.System#getLogger(java.lang.String)
1228 * @see java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
1229 * @see java.lang.System.LoggerFinder
1230 *
1231 * @since 9
1232 */
1233 public interface Logger {
1234
1235 /**
1236 * System {@linkplain Logger loggers} levels.
1237 *
1238 * A level has a {@linkplain #getName() name} and {@linkplain
1239 * #getSeverity() severity}.
1240 * Level values are {@link #ALL}, {@link #TRACE}, {@link #DEBUG},
1241 * {@link #INFO}, {@link #WARNING}, {@link #ERROR}, {@link #OFF},
1242 * by order of increasing severity.
1243 * <br>
1244 * {@link #ALL} and {@link #OFF}
1245 * are simple markers with severities mapped respectively to
1246 * {@link java.lang.Integer#MIN_VALUE Integer.MIN_VALUE} and
1247 * {@link java.lang.Integer#MAX_VALUE Integer.MAX_VALUE}.
1248 * <p>
1249 * <b>Severity values and Mapping to {@code java.util.logging.Level}.</b>
1250 * <p>
1251 * {@linkplain System.Logger.Level System logger levels} are mapped to
1252 * {@linkplain java.logging/java.util.logging.Level java.util.logging levels}
1253 * of corresponding severity.
1254 * <br>The mapping is as follows:
1255 * <br><br>
1256 * <table class="striped">
1257 * <caption>System.Logger Severity Level Mapping</caption>
1258 * <thead>
1259 * <tr><th scope="col">System.Logger Levels</th>
1260 * <th scope="col">java.util.logging Levels</th>
1261 * </thead>
1262 * <tbody>
1263 * <tr><th scope="row">{@link Logger.Level#ALL ALL}</th>
1264 * <td>{@link java.logging/java.util.logging.Level#ALL ALL}</td>
1265 * <tr><th scope="row">{@link Logger.Level#TRACE TRACE}</th>
1266 * <td>{@link java.logging/java.util.logging.Level#FINER FINER}</td>
1267 * <tr><th scope="row">{@link Logger.Level#DEBUG DEBUG}</th>
1268 * <td>{@link java.logging/java.util.logging.Level#FINE FINE}</td>
1269 * <tr><th scope="row">{@link Logger.Level#INFO INFO}</th>
1270 * <td>{@link java.logging/java.util.logging.Level#INFO INFO}</td>
1271 * <tr><th scope="row">{@link Logger.Level#WARNING WARNING}</th>
1272 * <td>{@link java.logging/java.util.logging.Level#WARNING WARNING}</td>
1273 * <tr><th scope="row">{@link Logger.Level#ERROR ERROR}</th>
1274 * <td>{@link java.logging/java.util.logging.Level#SEVERE SEVERE}</td>
1275 * <tr><th scope="row">{@link Logger.Level#OFF OFF}</th>
1276 * <td>{@link java.logging/java.util.logging.Level#OFF OFF}</td>
1277 * </tbody>
1278 * </table>
1279 *
1280 * @since 9
1281 *
1282 * @see java.lang.System.LoggerFinder
1283 * @see java.lang.System.Logger
1284 */
1285 @SuppressWarnings("doclint:reference") // cross-module links
1286 public enum Level {
1287
1288 // for convenience, we're reusing java.util.logging.Level int values
1289 // the mapping logic in sun.util.logging.PlatformLogger depends
1290 // on this.
1291 /**
1292 * A marker to indicate that all levels are enabled.
1293 * This level {@linkplain #getSeverity() severity} is
1294 * {@link Integer#MIN_VALUE}.
1295 */
1296 ALL(Integer.MIN_VALUE), // typically mapped to/from j.u.l.Level.ALL
1297 /**
1298 * {@code TRACE} level: usually used to log diagnostic information.
1299 * This level {@linkplain #getSeverity() severity} is
1300 * {@code 400}.
1301 */
1302 TRACE(400), // typically mapped to/from j.u.l.Level.FINER
1303 /**
1304 * {@code DEBUG} level: usually used to log debug information traces.
1305 * This level {@linkplain #getSeverity() severity} is
1306 * {@code 500}.
1307 */
1308 DEBUG(500), // typically mapped to/from j.u.l.Level.FINEST/FINE/CONFIG
1309 /**
1310 * {@code INFO} level: usually used to log information messages.
1311 * This level {@linkplain #getSeverity() severity} is
1312 * {@code 800}.
1313 */
1314 INFO(800), // typically mapped to/from j.u.l.Level.INFO
1315 /**
1316 * {@code WARNING} level: usually used to log warning messages.
1317 * This level {@linkplain #getSeverity() severity} is
1318 * {@code 900}.
1319 */
1320 WARNING(900), // typically mapped to/from j.u.l.Level.WARNING
1321 /**
1322 * {@code ERROR} level: usually used to log error messages.
1323 * This level {@linkplain #getSeverity() severity} is
1324 * {@code 1000}.
1325 */
1326 ERROR(1000), // typically mapped to/from j.u.l.Level.SEVERE
1327 /**
1328 * A marker to indicate that all levels are disabled.
1329 * This level {@linkplain #getSeverity() severity} is
1330 * {@link Integer#MAX_VALUE}.
1331 */
1332 OFF(Integer.MAX_VALUE); // typically mapped to/from j.u.l.Level.OFF
1333
1334 private final int severity;
1335
1336 private Level(int severity) {
1337 this.severity = severity;
1338 }
1339
1340 /**
1341 * Returns the name of this level.
1342 * @return this level {@linkplain #name()}.
1343 */
1344 public final String getName() {
1345 return name();
1346 }
1347
1348 /**
1349 * Returns the severity of this level.
1350 * A higher severity means a more severe condition.
1351 * @return this level severity.
1352 */
1353 public final int getSeverity() {
1354 return severity;
1355 }
1356 }
1357
1358 /**
1359 * Returns the name of this logger.
1360 *
1361 * @return the logger name.
1362 */
1363 public String getName();
1364
1365 /**
1366 * Checks if a message of the given level would be logged by
1367 * this logger.
1368 *
1369 * @param level the log message level.
1370 * @return {@code true} if the given log message level is currently
1371 * being logged.
1372 *
1373 * @throws NullPointerException if {@code level} is {@code null}.
1374 */
1375 public boolean isLoggable(Level level);
1376
1377 /**
1378 * Logs a message.
1379 *
1380 * @implSpec The default implementation for this method calls
1381 * {@code this.log(level, (ResourceBundle)null, msg, (Object[])null);}
1382 *
1383 * @param level the log message level.
1384 * @param msg the string message (or a key in the message catalog, if
1385 * this logger is a {@link
1386 * LoggerFinder#getLocalizedLogger(java.lang.String,
1387 * java.util.ResourceBundle, java.lang.Module) localized logger});
1388 * can be {@code null}.
1389 *
1390 * @throws NullPointerException if {@code level} is {@code null}.
1391 */
1392 public default void log(Level level, String msg) {
1393 log(level, (ResourceBundle) null, msg, (Object[]) null);
1394 }
1395
1396 /**
1397 * Logs a lazily supplied message.
1398 *
1399 * If the logger is currently enabled for the given log message level
1400 * then a message is logged that is the result produced by the
1401 * given supplier function. Otherwise, the supplier is not operated on.
1402 *
1403 * @implSpec When logging is enabled for the given level, the default
1404 * implementation for this method calls
1405 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), (Object[])null);}
1406 *
1407 * @param level the log message level.
1408 * @param msgSupplier a supplier function that produces a message.
1409 *
1410 * @throws NullPointerException if {@code level} is {@code null},
1411 * or {@code msgSupplier} is {@code null}.
1412 */
1413 public default void log(Level level, Supplier<String> msgSupplier) {
1414 Objects.requireNonNull(msgSupplier);
1415 if (isLoggable(Objects.requireNonNull(level))) {
1416 log(level, (ResourceBundle) null, msgSupplier.get(), (Object[]) null);
1417 }
1418 }
1419
1420 /**
1421 * Logs a message produced from the given object.
1422 *
1423 * If the logger is currently enabled for the given log message level then
1424 * a message is logged that, by default, is the result produced from
1425 * calling toString on the given object.
1426 * Otherwise, the object is not operated on.
1427 *
1428 * @implSpec When logging is enabled for the given level, the default
1429 * implementation for this method calls
1430 * {@code this.log(level, (ResourceBundle)null, obj.toString(), (Object[])null);}
1431 *
1432 * @param level the log message level.
1433 * @param obj the object to log.
1434 *
1435 * @throws NullPointerException if {@code level} is {@code null}, or
1436 * {@code obj} is {@code null}.
1437 */
1438 public default void log(Level level, Object obj) {
1439 Objects.requireNonNull(obj);
1440 if (isLoggable(Objects.requireNonNull(level))) {
1441 this.log(level, (ResourceBundle) null, obj.toString(), (Object[]) null);
1442 }
1443 }
1444
1445 /**
1446 * Logs a message associated with a given throwable.
1447 *
1448 * @implSpec The default implementation for this method calls
1449 * {@code this.log(level, (ResourceBundle)null, msg, thrown);}
1450 *
1451 * @param level the log message level.
1452 * @param msg the string message (or a key in the message catalog, if
1453 * this logger is a {@link
1454 * LoggerFinder#getLocalizedLogger(java.lang.String,
1455 * java.util.ResourceBundle, java.lang.Module) localized logger});
1456 * can be {@code null}.
1457 * @param thrown a {@code Throwable} associated with the log message;
1458 * can be {@code null}.
1459 *
1460 * @throws NullPointerException if {@code level} is {@code null}.
1461 */
1462 public default void log(Level level, String msg, Throwable thrown) {
1463 this.log(level, null, msg, thrown);
1464 }
1465
1466 /**
1467 * Logs a lazily supplied message associated with a given throwable.
1468 *
1469 * If the logger is currently enabled for the given log message level
1470 * then a message is logged that is the result produced by the
1471 * given supplier function. Otherwise, the supplier is not operated on.
1472 *
1473 * @implSpec When logging is enabled for the given level, the default
1474 * implementation for this method calls
1475 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), thrown);}
1476 *
1477 * @param level one of the log message level identifiers.
1478 * @param msgSupplier a supplier function that produces a message.
1479 * @param thrown a {@code Throwable} associated with log message;
1480 * can be {@code null}.
1481 *
1482 * @throws NullPointerException if {@code level} is {@code null}, or
1483 * {@code msgSupplier} is {@code null}.
1484 */
1485 public default void log(Level level, Supplier<String> msgSupplier,
1486 Throwable thrown) {
1487 Objects.requireNonNull(msgSupplier);
1488 if (isLoggable(Objects.requireNonNull(level))) {
1489 this.log(level, null, msgSupplier.get(), thrown);
1490 }
1491 }
1492
1493 /**
1494 * Logs a message with an optional list of parameters.
1495 *
1496 * @implSpec The default implementation for this method calls
1497 * {@code this.log(level, (ResourceBundle)null, format, params);}
1498 *
1499 * @param level one of the log message level identifiers.
1500 * @param format the string message format in {@link
1501 * java.text.MessageFormat} format, (or a key in the message
1502 * catalog, if this logger is a {@link
1503 * LoggerFinder#getLocalizedLogger(java.lang.String,
1504 * java.util.ResourceBundle, java.lang.Module) localized logger});
1505 * can be {@code null}.
1506 * @param params an optional list of parameters to the message (may be
1507 * none).
1508 *
1509 * @throws NullPointerException if {@code level} is {@code null}.
1510 */
1511 public default void log(Level level, String format, Object... params) {
1512 this.log(level, null, format, params);
1513 }
1514
1515 /**
1516 * Logs a localized message associated with a given throwable.
1517 *
1518 * If the given resource bundle is non-{@code null}, the {@code msg}
1519 * string is localized using the given resource bundle.
1520 * Otherwise the {@code msg} string is not localized.
1521 *
1522 * @param level the log message level.
1523 * @param bundle a resource bundle to localize {@code msg}; can be
1524 * {@code null}.
1525 * @param msg the string message (or a key in the message catalog,
1526 * if {@code bundle} is not {@code null}); can be {@code null}.
1527 * @param thrown a {@code Throwable} associated with the log message;
1528 * can be {@code null}.
1529 *
1530 * @throws NullPointerException if {@code level} is {@code null}.
1531 */
1532 public void log(Level level, ResourceBundle bundle, String msg,
1533 Throwable thrown);
1534
1535 /**
1536 * Logs a message with resource bundle and an optional list of
1537 * parameters.
1538 *
1539 * If the given resource bundle is non-{@code null}, the {@code format}
1540 * string is localized using the given resource bundle.
1541 * Otherwise the {@code format} string is not localized.
1542 *
1543 * @param level the log message level.
1544 * @param bundle a resource bundle to localize {@code format}; can be
1545 * {@code null}.
1546 * @param format the string message format in {@link
1547 * java.text.MessageFormat} format, (or a key in the message
1548 * catalog if {@code bundle} is not {@code null}); can be {@code null}.
1549 * @param params an optional list of parameters to the message (may be
1550 * none).
1551 *
1552 * @throws NullPointerException if {@code level} is {@code null}.
1553 */
1554 public void log(Level level, ResourceBundle bundle, String format,
1555 Object... params);
1556 }
1557
1558 /**
1559 * The {@code LoggerFinder} service is responsible for creating, managing,
1560 * and configuring loggers to the underlying framework it uses.
1561 *
1562 * A logger finder is a concrete implementation of this class that has a
1563 * zero-argument constructor and implements the abstract methods defined
1564 * by this class.
1565 * The loggers returned from a logger finder are capable of routing log
1566 * messages to the logging backend this provider supports.
1567 * A given invocation of the Java Runtime maintains a single
1568 * system-wide LoggerFinder instance that is loaded as follows:
1569 * <ul>
1570 * <li>First it finds any custom {@code LoggerFinder} provider
1571 * using the {@link java.util.ServiceLoader} facility with the
1572 * {@linkplain ClassLoader#getSystemClassLoader() system class
1573 * loader}.</li>
1574 * <li>If no {@code LoggerFinder} provider is found, the system default
1575 * {@code LoggerFinder} implementation will be used.</li>
1576 * </ul>
1577 * <p>
1578 * An application can replace the logging backend
1579 * <i>even when the java.logging module is present</i>, by simply providing
1580 * and declaring an implementation of the {@link LoggerFinder} service.
1581 * <p>
1582 * <b>Default Implementation</b>
1583 * <p>
1584 * The system default {@code LoggerFinder} implementation uses
1585 * {@code java.util.logging} as the backend framework when the
1586 * {@code java.logging} module is present.
1587 * It returns a {@linkplain System.Logger logger} instance
1588 * that will route log messages to a {@link java.logging/java.util.logging.Logger
1589 * java.util.logging.Logger}. Otherwise, if {@code java.logging} is not
1590 * present, the default implementation will return a simple logger
1591 * instance that will route log messages of {@code INFO} level and above to
1592 * the console ({@code System.err}).
1593 * <p>
1594 * <b>Logging Configuration</b>
1595 * <p>
1596 * {@linkplain Logger Logger} instances obtained from the
1597 * {@code LoggerFinder} factory methods are not directly configurable by
1598 * the application. Configuration is the responsibility of the underlying
1599 * logging backend, and usually requires using APIs specific to that backend.
1600 * <p>For the default {@code LoggerFinder} implementation
1601 * using {@code java.util.logging} as its backend, refer to
1602 * {@link java.logging/java.util.logging java.util.logging} for logging configuration.
1603 * For the default {@code LoggerFinder} implementation returning simple loggers
1604 * when the {@code java.logging} module is absent, the configuration
1605 * is implementation dependent.
1606 * <p>
1607 * Usually an application that uses a logging framework will log messages
1608 * through a logger facade defined (or supported) by that framework.
1609 * Applications that wish to use an external framework should log
1610 * through the facade associated with that framework.
1611 * <p>
1612 * A system class that needs to log messages will typically obtain
1613 * a {@link System.Logger} instance to route messages to the logging
1614 * framework selected by the application.
1615 * <p>
1616 * Libraries and classes that only need loggers to produce log messages
1617 * should not attempt to configure loggers by themselves, as that
1618 * would make them dependent from a specific implementation of the
1619 * {@code LoggerFinder} service.
1620 * <p>
1621 * In addition, when a security manager is present, loggers provided to
1622 * system classes should not be directly configurable through the logging
1623 * backend without requiring permissions.
1624 * <br>
1625 * It is the responsibility of the provider of
1626 * the concrete {@code LoggerFinder} implementation to ensure that
1627 * these loggers are not configured by untrusted code without proper
1628 * permission checks, as configuration performed on such loggers usually
1629 * affects all applications in the same Java Runtime.
1630 * <p>
1631 * <b>Message Levels and Mapping to backend levels</b>
1632 * <p>
1633 * A logger finder is responsible for mapping from a {@code
1634 * System.Logger.Level} to a level supported by the logging backend it uses.
1635 * <br>The default LoggerFinder using {@code java.util.logging} as the backend
1636 * maps {@code System.Logger} levels to
1637 * {@linkplain java.logging/java.util.logging.Level java.util.logging} levels
1638 * of corresponding severity - as described in {@link Logger.Level
1639 * Logger.Level}.
1640 *
1641 * @see java.lang.System
1642 * @see java.lang.System.Logger
1643 *
1644 * @since 9
1645 */
1646 @SuppressWarnings("doclint:reference") // cross-module links
1647 public abstract static class LoggerFinder {
1648 /**
1649 * The {@code RuntimePermission("loggerFinder")} is
1650 * necessary to subclass and instantiate the {@code LoggerFinder} class,
1651 * as well as to obtain loggers from an instance of that class.
1652 */
1653 static final RuntimePermission LOGGERFINDER_PERMISSION =
1654 new RuntimePermission("loggerFinder");
1655
1656 /**
1657 * Creates a new instance of {@code LoggerFinder}.
1658 *
1659 * @implNote It is recommended that a {@code LoggerFinder} service
1660 * implementation does not perform any heavy initialization in its
1661 * constructor, in order to avoid possible risks of deadlock or class
1662 * loading cycles during the instantiation of the service provider.
1663 *
1664 * @throws SecurityException if a security manager is present and its
1665 * {@code checkPermission} method doesn't allow the
1666 * {@code RuntimePermission("loggerFinder")}.
1667 */
1668 protected LoggerFinder() {
1669 this(checkPermission());
1670 }
1671
1672 private LoggerFinder(Void unused) {
1673 // nothing to do.
1674 }
1675
1676 private static Void checkPermission() {
1677 @SuppressWarnings("removal")
1678 final SecurityManager sm = System.getSecurityManager();
1679 if (sm != null) {
1680 sm.checkPermission(LOGGERFINDER_PERMISSION);
1681 }
1682 return null;
1683 }
1684
1685 /**
1686 * Returns an instance of {@link Logger Logger}
1687 * for the given {@code module}.
1688 *
1689 * @param name the name of the logger.
1690 * @param module the module for which the logger is being requested.
1691 *
1692 * @return a {@link Logger logger} suitable for use within the given
1693 * module.
1694 * @throws NullPointerException if {@code name} is {@code null} or
1695 * {@code module} is {@code null}.
1696 * @throws SecurityException if a security manager is present and its
1697 * {@code checkPermission} method doesn't allow the
1698 * {@code RuntimePermission("loggerFinder")}.
1699 */
1700 public abstract Logger getLogger(String name, Module module);
1701
1702 /**
1703 * Returns a localizable instance of {@link Logger Logger}
1704 * for the given {@code module}.
1705 * The returned logger will use the provided resource bundle for
1706 * message localization.
1707 *
1708 * @implSpec By default, this method calls {@link
1709 * #getLogger(java.lang.String, java.lang.Module)
1710 * this.getLogger(name, module)} to obtain a logger, then wraps that
1711 * logger in a {@link Logger} instance where all methods that do not
1712 * take a {@link ResourceBundle} as parameter are redirected to one
1713 * which does - passing the given {@code bundle} for
1714 * localization. So for instance, a call to {@link
1715 * Logger#log(Logger.Level, String) Logger.log(Level.INFO, msg)}
1716 * will end up as a call to {@link
1717 * Logger#log(Logger.Level, ResourceBundle, String, Object...)
1718 * Logger.log(Level.INFO, bundle, msg, (Object[])null)} on the wrapped
1719 * logger instance.
1720 * Note however that by default, string messages returned by {@link
1721 * java.util.function.Supplier Supplier<String>} will not be
1722 * localized, as it is assumed that such strings are messages which are
1723 * already constructed, rather than keys in a resource bundle.
1724 * <p>
1725 * An implementation of {@code LoggerFinder} may override this method,
1726 * for example, when the underlying logging backend provides its own
1727 * mechanism for localizing log messages, then such a
1728 * {@code LoggerFinder} would be free to return a logger
1729 * that makes direct use of the mechanism provided by the backend.
1730 *
1731 * @param name the name of the logger.
1732 * @param bundle a resource bundle; can be {@code null}.
1733 * @param module the module for which the logger is being requested.
1734 * @return an instance of {@link Logger Logger} which will use the
1735 * provided resource bundle for message localization.
1736 *
1737 * @throws NullPointerException if {@code name} is {@code null} or
1738 * {@code module} is {@code null}.
1739 * @throws SecurityException if a security manager is present and its
1740 * {@code checkPermission} method doesn't allow the
1741 * {@code RuntimePermission("loggerFinder")}.
1742 */
1743 public Logger getLocalizedLogger(String name, ResourceBundle bundle,
1744 Module module) {
1745 return new LocalizedLoggerWrapper<>(getLogger(name, module), bundle);
1746 }
1747
1748 /**
1749 * Returns the {@code LoggerFinder} instance. There is one
1750 * single system-wide {@code LoggerFinder} instance in
1751 * the Java Runtime. See the class specification of how the
1752 * {@link LoggerFinder LoggerFinder} implementation is located and
1753 * loaded.
1754 *
1755 * @return the {@link LoggerFinder LoggerFinder} instance.
1756 * @throws SecurityException if a security manager is present and its
1757 * {@code checkPermission} method doesn't allow the
1758 * {@code RuntimePermission("loggerFinder")}.
1759 */
1760 public static LoggerFinder getLoggerFinder() {
1761 @SuppressWarnings("removal")
1762 final SecurityManager sm = System.getSecurityManager();
1763 if (sm != null) {
1764 sm.checkPermission(LOGGERFINDER_PERMISSION);
1765 }
1766 return accessProvider();
1767 }
1768
1769
1770 private static volatile LoggerFinder service;
1771 @SuppressWarnings("removal")
1772 static LoggerFinder accessProvider() {
1773 // We do not need to synchronize: LoggerFinderLoader will
1774 // always return the same instance, so if we don't have it,
1775 // just fetch it again.
1776 LoggerFinder finder = service;
1777 if (finder == null) {
1778 PrivilegedAction<LoggerFinder> pa =
1779 () -> LoggerFinderLoader.getLoggerFinder();
1780 finder = AccessController.doPrivileged(pa, null,
1781 LOGGERFINDER_PERMISSION);
1782 if (finder instanceof TemporaryLoggerFinder) return finder;
1783 service = finder;
1784 }
1785 return finder;
1786 }
1787
1788 }
1789
1790
1791 /**
1792 * Returns an instance of {@link Logger Logger} for the caller's
1793 * use.
1794 *
1795 * @implSpec
1796 * Instances returned by this method route messages to loggers
1797 * obtained by calling {@link LoggerFinder#getLogger(java.lang.String,
1798 * java.lang.Module) LoggerFinder.getLogger(name, module)}, where
1799 * {@code module} is the caller's module.
1800 * In cases where {@code System.getLogger} is called from a context where
1801 * there is no caller frame on the stack (e.g when called directly
1802 * from a JNI attached thread), {@code IllegalCallerException} is thrown.
1803 * To obtain a logger in such a context, use an auxiliary class that will
1804 * implicitly be identified as the caller, or use the system {@link
1805 * LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
1806 * Note that doing the latter may eagerly initialize the underlying
1807 * logging system.
1808 *
1809 * @apiNote
1810 * This method may defer calling the {@link
1811 * LoggerFinder#getLogger(java.lang.String, java.lang.Module)
1812 * LoggerFinder.getLogger} method to create an actual logger supplied by
1813 * the logging backend, for instance, to allow loggers to be obtained during
1814 * the system initialization time.
1815 *
1816 * @param name the name of the logger.
1817 * @return an instance of {@link Logger} that can be used by the calling
1818 * class.
1819 * @throws NullPointerException if {@code name} is {@code null}.
1820 * @throws IllegalCallerException if there is no Java caller frame on the
1821 * stack.
1822 *
1823 * @since 9
1824 */
1825 @CallerSensitive
1826 public static Logger getLogger(String name) {
1827 Objects.requireNonNull(name);
1828 final Class<?> caller = Reflection.getCallerClass();
1829 if (caller == null) {
1830 throw new IllegalCallerException("no caller frame");
1831 }
1832 return LazyLoggers.getLogger(name, caller.getModule());
1833 }
1834
1835 /**
1836 * Returns a localizable instance of {@link Logger
1837 * Logger} for the caller's use.
1838 * The returned logger will use the provided resource bundle for message
1839 * localization.
1840 *
1841 * @implSpec
1842 * The returned logger will perform message localization as specified
1843 * by {@link LoggerFinder#getLocalizedLogger(java.lang.String,
1844 * java.util.ResourceBundle, java.lang.Module)
1845 * LoggerFinder.getLocalizedLogger(name, bundle, module)}, where
1846 * {@code module} is the caller's module.
1847 * In cases where {@code System.getLogger} is called from a context where
1848 * there is no caller frame on the stack (e.g when called directly
1849 * from a JNI attached thread), {@code IllegalCallerException} is thrown.
1850 * To obtain a logger in such a context, use an auxiliary class that
1851 * will implicitly be identified as the caller, or use the system {@link
1852 * LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
1853 * Note that doing the latter may eagerly initialize the underlying
1854 * logging system.
1855 *
1856 * @apiNote
1857 * This method is intended to be used after the system is fully initialized.
1858 * This method may trigger the immediate loading and initialization
1859 * of the {@link LoggerFinder} service, which may cause issues if the
1860 * Java Runtime is not ready to initialize the concrete service
1861 * implementation yet.
1862 * System classes which may be loaded early in the boot sequence and
1863 * need to log localized messages should create a logger using
1864 * {@link #getLogger(java.lang.String)} and then use the log methods that
1865 * take a resource bundle as parameter.
1866 *
1867 * @param name the name of the logger.
1868 * @param bundle a resource bundle.
1869 * @return an instance of {@link Logger} which will use the provided
1870 * resource bundle for message localization.
1871 * @throws NullPointerException if {@code name} is {@code null} or
1872 * {@code bundle} is {@code null}.
1873 * @throws IllegalCallerException if there is no Java caller frame on the
1874 * stack.
1875 *
1876 * @since 9
1877 */
1878 @SuppressWarnings("removal")
1879 @CallerSensitive
1880 public static Logger getLogger(String name, ResourceBundle bundle) {
1881 final ResourceBundle rb = Objects.requireNonNull(bundle);
1882 Objects.requireNonNull(name);
1883 final Class<?> caller = Reflection.getCallerClass();
1884 if (caller == null) {
1885 throw new IllegalCallerException("no caller frame");
1886 }
1887 final SecurityManager sm = System.getSecurityManager();
1888 // We don't use LazyLoggers if a resource bundle is specified.
1889 // Bootstrap sensitive classes in the JDK do not use resource bundles
1890 // when logging. This could be revisited later, if it needs to.
1891 if (sm != null) {
1892 final PrivilegedAction<Logger> pa =
1893 () -> LoggerFinder.accessProvider()
1894 .getLocalizedLogger(name, rb, caller.getModule());
1895 return AccessController.doPrivileged(pa, null,
1896 LoggerFinder.LOGGERFINDER_PERMISSION);
1897 }
1898 return LoggerFinder.accessProvider()
1899 .getLocalizedLogger(name, rb, caller.getModule());
1900 }
1901
1902 /**
1903 * Initiates the {@linkplain Runtime##shutdown shutdown sequence} of the Java Virtual Machine.
1904 * Unless the security manager denies exiting, this method initiates the shutdown sequence
1905 * (if it is not already initiated) and then blocks indefinitely. This method neither returns
1906 * nor throws an exception; that is, it does not complete either normally or abruptly.
1907 * <p>
1908 * The argument serves as a status code. By convention, a nonzero status code
1909 * indicates abnormal termination.
1910 * <p>
1911 * The call {@code System.exit(n)} is effectively equivalent to the call:
1912 * {@snippet :
1913 * Runtime.getRuntime().exit(n)
1914 * }
1915 *
1916 * @implNote
1917 * The initiation of the shutdown sequence is logged by {@link Runtime#exit(int)}.
1918 *
1919 * @param status exit status.
1920 * @throws SecurityException
1921 * if a security manager exists and its {@code checkExit} method
1922 * doesn't allow exit with the specified status.
1923 * @see java.lang.Runtime#exit(int)
1924 */
1925 public static void exit(int status) {
1926 Runtime.getRuntime().exit(status);
1927 }
1928
1929 /**
1930 * Runs the garbage collector in the Java Virtual Machine.
1931 * <p>
1932 * Calling the {@code gc} method suggests that the Java Virtual Machine
1933 * expend effort toward recycling unused objects in order to
1934 * make the memory they currently occupy available for reuse
1935 * by the Java Virtual Machine.
1936 * When control returns from the method call, the Java Virtual Machine
1937 * has made a best effort to reclaim space from all unused objects.
1938 * There is no guarantee that this effort will recycle any particular
1939 * number of unused objects, reclaim any particular amount of space, or
1940 * complete at any particular time, if at all, before the method returns or ever.
1941 * There is also no guarantee that this effort will determine
1942 * the change of reachability in any particular number of objects,
1943 * or that any particular number of {@link java.lang.ref.Reference Reference}
1944 * objects will be cleared and enqueued.
1945 *
1946 * <p>
1947 * The call {@code System.gc()} is effectively equivalent to the
1948 * call:
1949 * <blockquote><pre>
1950 * Runtime.getRuntime().gc()
1951 * </pre></blockquote>
1952 *
1953 * @see java.lang.Runtime#gc()
1954 */
1955 public static void gc() {
1956 Runtime.getRuntime().gc();
1957 }
1958
1959 /**
1960 * Runs the finalization methods of any objects pending finalization.
1961 *
1962 * Calling this method suggests that the Java Virtual Machine expend
1963 * effort toward running the {@code finalize} methods of objects
1964 * that have been found to be discarded but whose {@code finalize}
1965 * methods have not yet been run. When control returns from the
1966 * method call, the Java Virtual Machine has made a best effort to
1967 * complete all outstanding finalizations.
1968 * <p>
1969 * The call {@code System.runFinalization()} is effectively
1970 * equivalent to the call:
1971 * <blockquote><pre>
1972 * Runtime.getRuntime().runFinalization()
1973 * </pre></blockquote>
1974 *
1975 * @deprecated Finalization has been deprecated for removal. See
1976 * {@link java.lang.Object#finalize} for background information and details
1977 * about migration options.
1978 * <p>
1979 * When running in a JVM in which finalization has been disabled or removed,
1980 * no objects will be pending finalization, so this method does nothing.
1981 *
1982 * @see java.lang.Runtime#runFinalization()
1983 * @jls 12.6 Finalization of Class Instances
1984 */
1985 @Deprecated(since="18", forRemoval=true)
1986 @SuppressWarnings("removal")
1987 public static void runFinalization() {
1988 Runtime.getRuntime().runFinalization();
1989 }
1990
1991 /**
1992 * Loads the native library specified by the filename argument. The filename
1993 * argument must be an absolute path name.
1994 *
1995 * If the filename argument, when stripped of any platform-specific library
1996 * prefix, path, and file extension, indicates a library whose name is,
1997 * for example, L, and a native library called L is statically linked
1998 * with the VM, then the JNI_OnLoad_L function exported by the library
1999 * is invoked rather than attempting to load a dynamic library.
2000 * A filename matching the argument does not have to exist in the
2001 * file system.
2002 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
2003 * for more details.
2004 *
2005 * Otherwise, the filename argument is mapped to a native library image in
2006 * an implementation-dependent manner.
2007 *
2008 * <p>
2009 * The call {@code System.load(name)} is effectively equivalent
2010 * to the call:
2011 * <blockquote><pre>
2012 * Runtime.getRuntime().load(name)
2013 * </pre></blockquote>
2014 *
2015 * @param filename the file to load.
2016 * @throws SecurityException if a security manager exists and its
2017 * {@code checkLink} method doesn't allow
2018 * loading of the specified dynamic library
2019 * @throws UnsatisfiedLinkError if either the filename is not an
2020 * absolute path name, the native library is not statically
2021 * linked with the VM, or the library cannot be mapped to
2022 * a native library image by the host system.
2023 * @throws NullPointerException if {@code filename} is {@code null}
2024 * @throws IllegalCallerException if the caller is in a module that
2025 * does not have native access enabled.
2026 *
2027 * @spec jni/index.html Java Native Interface Specification
2028 * @see java.lang.Runtime#load(java.lang.String)
2029 * @see java.lang.SecurityManager#checkLink(java.lang.String)
2030 */
2031 @CallerSensitive
2032 @Restricted
2033 public static void load(String filename) {
2034 Class<?> caller = Reflection.getCallerClass();
2035 Reflection.ensureNativeAccess(caller, System.class, "load", false);
2036 Runtime.getRuntime().load0(caller, filename);
2037 }
2038
2039 /**
2040 * Loads the native library specified by the {@code libname}
2041 * argument. The {@code libname} argument must not contain any platform
2042 * specific prefix, file extension or path. If a native library
2043 * called {@code libname} is statically linked with the VM, then the
2044 * JNI_OnLoad_{@code libname} function exported by the library is invoked.
2045 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
2046 * for more details.
2047 *
2048 * Otherwise, the libname argument is loaded from a system library
2049 * location and mapped to a native library image in an
2050 * implementation-dependent manner.
2051 * <p>
2052 * The call {@code System.loadLibrary(name)} is effectively
2053 * equivalent to the call
2054 * <blockquote><pre>
2055 * Runtime.getRuntime().loadLibrary(name)
2056 * </pre></blockquote>
2057 *
2058 * @param libname the name of the library.
2059 * @throws SecurityException if a security manager exists and its
2060 * {@code checkLink} method doesn't allow
2061 * loading of the specified dynamic library
2062 * @throws UnsatisfiedLinkError if either the libname argument
2063 * contains a file path, the native library is not statically
2064 * linked with the VM, or the library cannot be mapped to a
2065 * native library image by the host system.
2066 * @throws NullPointerException if {@code libname} is {@code null}
2067 * @throws IllegalCallerException if the caller is in a module that
2068 * does not have native access enabled.
2069 *
2070 * @spec jni/index.html Java Native Interface Specification
2071 * @see java.lang.Runtime#loadLibrary(java.lang.String)
2072 * @see java.lang.SecurityManager#checkLink(java.lang.String)
2073 */
2074 @CallerSensitive
2075 @Restricted
2076 public static void loadLibrary(String libname) {
2077 Class<?> caller = Reflection.getCallerClass();
2078 Reflection.ensureNativeAccess(caller, System.class, "loadLibrary", false);
2079 Runtime.getRuntime().loadLibrary0(caller, libname);
2080 }
2081
2082 /**
2083 * Maps a library name into a platform-specific string representing
2084 * a native library.
2085 *
2086 * @param libname the name of the library.
2087 * @return a platform-dependent native library name.
2088 * @throws NullPointerException if {@code libname} is {@code null}
2089 * @see java.lang.System#loadLibrary(java.lang.String)
2090 * @see java.lang.ClassLoader#findLibrary(java.lang.String)
2091 * @since 1.2
2092 */
2093 public static native String mapLibraryName(String libname);
2094
2095 /**
2096 * Create PrintStream for stdout/err based on encoding.
2097 */
2098 private static PrintStream newPrintStream(OutputStream out, String enc) {
2099 if (enc != null) {
2100 return new PrintStream(new BufferedOutputStream(out, 128), true,
2101 Charset.forName(enc, UTF_8.INSTANCE));
2102 }
2103 return new PrintStream(new BufferedOutputStream(out, 128), true);
2104 }
2105
2106 /**
2107 * Logs an exception/error at initialization time to stdout or stderr.
2108 *
2109 * @param printToStderr to print to stderr rather than stdout
2110 * @param printStackTrace to print the stack trace
2111 * @param msg the message to print before the exception, can be {@code null}
2112 * @param e the exception or error
2113 */
2114 private static void logInitException(boolean printToStderr,
2115 boolean printStackTrace,
2116 String msg,
2117 Throwable e) {
2118 if (VM.initLevel() < 1) {
2119 throw new InternalError("system classes not initialized");
2120 }
2121 PrintStream log = (printToStderr) ? err : out;
2122 if (msg != null) {
2123 log.println(msg);
2124 }
2125 if (printStackTrace) {
2126 e.printStackTrace(log);
2127 } else {
2128 log.println(e);
2129 for (Throwable suppressed : e.getSuppressed()) {
2130 log.println("Suppressed: " + suppressed);
2131 }
2132 Throwable cause = e.getCause();
2133 if (cause != null) {
2134 log.println("Caused by: " + cause);
2135 }
2136 }
2137 }
2138
2139 /**
2140 * Create the Properties object from a map - masking out system properties
2141 * that are not intended for public access.
2142 */
2143 private static Properties createProperties(Map<String, String> initialProps) {
2144 Properties properties = new Properties(initialProps.size());
2145 for (var entry : initialProps.entrySet()) {
2146 String prop = entry.getKey();
2147 switch (prop) {
2148 // Do not add private system properties to the Properties
2149 case "sun.nio.MaxDirectMemorySize":
2150 case "sun.nio.PageAlignDirectMemory":
2151 // used by java.lang.Integer.IntegerCache
2152 case "java.lang.Integer.IntegerCache.high":
2153 // used by sun.launcher.LauncherHelper
2154 case "sun.java.launcher.diag":
2155 // used by jdk.internal.loader.ClassLoaders
2156 case "jdk.boot.class.path.append":
2157 break;
2158 default:
2159 properties.put(prop, entry.getValue());
2160 }
2161 }
2162 return properties;
2163 }
2164
2165 /**
2166 * Initialize the system class. Called after thread initialization.
2167 */
2168 private static void initPhase1() {
2169
2170 // register the shared secrets - do this first, since SystemProps.initProperties
2171 // might initialize CharsetDecoders that rely on it
2172 setJavaLangAccess();
2173
2174 // VM might invoke JNU_NewStringPlatform() to set those encoding
2175 // sensitive properties (user.home, user.name, boot.class.path, etc.)
2176 // during "props" initialization.
2177 // The charset is initialized in System.c and does not depend on the Properties.
2178 Map<String, String> tempProps = SystemProps.initProperties();
2179 VersionProps.init(tempProps);
2180
2181 // There are certain system configurations that may be controlled by
2182 // VM options such as the maximum amount of direct memory and
2183 // Integer cache size used to support the object identity semantics
2184 // of autoboxing. Typically, the library will obtain these values
2185 // from the properties set by the VM. If the properties are for
2186 // internal implementation use only, these properties should be
2187 // masked from the system properties.
2188 //
2189 // Save a private copy of the system properties object that
2190 // can only be accessed by the internal implementation.
2191 VM.saveProperties(tempProps);
2192 props = createProperties(tempProps);
2193
2194 // Check if sun.jnu.encoding is supported. If not, replace it with UTF-8.
2195 var jnuEncoding = props.getProperty("sun.jnu.encoding");
2196 if (jnuEncoding == null || !Charset.isSupported(jnuEncoding)) {
2197 notSupportedJnuEncoding = jnuEncoding == null ? "null" : jnuEncoding;
2198 props.setProperty("sun.jnu.encoding", "UTF-8");
2199 }
2200
2201 StaticProperty.javaHome(); // Load StaticProperty to cache the property values
2202
2203 lineSeparator = props.getProperty("line.separator");
2204
2205 FileInputStream fdIn = new In(FileDescriptor.in);
2206 FileOutputStream fdOut = new Out(FileDescriptor.out);
2207 FileOutputStream fdErr = new Out(FileDescriptor.err);
2208 initialIn = new BufferedInputStream(fdIn);
2209 setIn0(initialIn);
2210 // stdout/err.encoding are set when the VM is associated with the terminal,
2211 // thus they are equivalent to Console.charset(), otherwise the encodings
2212 // of those properties default to native.encoding
2213 setOut0(newPrintStream(fdOut, props.getProperty("stdout.encoding")));
2214 initialErr = newPrintStream(fdErr, props.getProperty("stderr.encoding"));
2215 setErr0(initialErr);
2216
2217 // Setup Java signal handlers for HUP, TERM, and INT (where available).
2218 Terminator.setup();
2219
2220 // Initialize any miscellaneous operating system settings that need to be
2221 // set for the class libraries. Currently this is no-op everywhere except
2222 // for Windows where the process-wide error mode is set before the java.io
2223 // classes are used.
2224 VM.initializeOSEnvironment();
2225
2226 // start Finalizer and Reference Handler threads
2227 SharedSecrets.getJavaLangRefAccess().startThreads();
2228
2229 // system properties, java.lang and other core classes are now initialized
2230 VM.initLevel(1);
2231 }
2232
2233 /**
2234 * System.in.
2235 */
2236 private static class In extends FileInputStream {
2237 In(FileDescriptor fd) {
2238 super(fd);
2239 }
2240
2241 @Override
2242 public int read() throws IOException {
2243 boolean attempted = Blocker.begin();
2244 try {
2245 return super.read();
2246 } finally {
2247 Blocker.end(attempted);
2248 }
2249 }
2250
2251 @Override
2252 public int read(byte[] b) throws IOException {
2253 boolean attempted = Blocker.begin();
2254 try {
2255 return super.read(b);
2256 } finally {
2257 Blocker.end(attempted);
2258 }
2259 }
2260
2261 @Override
2262 public int read(byte[] b, int off, int len) throws IOException {
2263 boolean attempted = Blocker.begin();
2264 try {
2265 return super.read(b, off, len);
2266 } finally {
2267 Blocker.end(attempted);
2268 }
2269 }
2270 }
2271
2272 /**
2273 * System.out/System.err wrap this output stream.
2274 */
2275 private static class Out extends FileOutputStream {
2276 Out(FileDescriptor fd) {
2277 super(fd);
2278 }
2279
2280 @Override
2281 public void write(int b) throws IOException {
2282 boolean attempted = Blocker.begin();
2283 try {
2284 super.write(b);
2285 } finally {
2286 Blocker.end(attempted);
2287 }
2288 }
2289
2290 @Override
2291 public void write(byte[] b) throws IOException {
2292 boolean attempted = Blocker.begin();
2293 try {
2294 super.write(b);
2295 } finally {
2296 Blocker.end(attempted);
2297 }
2298 }
2299
2300 @Override
2301 public void write(byte[] b, int off, int len) throws IOException {
2302 boolean attempted = Blocker.begin();
2303 try {
2304 super.write(b, off, len);
2305 } finally {
2306 Blocker.end(attempted);
2307 }
2308 }
2309 }
2310
2311 // @see #initPhase2()
2312 static ModuleLayer bootLayer;
2313
2314 /*
2315 * Invoked by VM. Phase 2 module system initialization.
2316 * Only classes in java.base can be loaded in this phase.
2317 *
2318 * @param printToStderr print exceptions to stderr rather than stdout
2319 * @param printStackTrace print stack trace when exception occurs
2320 *
2321 * @return JNI_OK for success, JNI_ERR for failure
2322 */
2323 private static int initPhase2(boolean printToStderr, boolean printStackTrace) {
2324
2325 try {
2326 bootLayer = ModuleBootstrap.boot();
2327 } catch (Exception | Error e) {
2328 logInitException(printToStderr, printStackTrace,
2329 "Error occurred during initialization of boot layer", e);
2330 return -1; // JNI_ERR
2331 }
2332
2333 // module system initialized
2334 VM.initLevel(2);
2335
2336 return 0; // JNI_OK
2337 }
2338
2339 /*
2340 * Invoked by VM. Phase 3 is the final system initialization:
2341 * 1. eagerly initialize bootstrap method factories that might interact
2342 * negatively with custom security managers and custom class loaders
2343 * 2. set security manager
2344 * 3. set system class loader
2345 * 4. set TCCL
2346 *
2347 * This method must be called after the module system initialization.
2348 * The security manager and system class loader may be a custom class from
2349 * the application classpath or modulepath.
2350 */
2351 @SuppressWarnings("removal")
2352 private static void initPhase3() {
2353
2354 // Initialize the StringConcatFactory eagerly to avoid potential
2355 // bootstrap circularity issues that could be caused by a custom
2356 // SecurityManager
2357 Unsafe.getUnsafe().ensureClassInitialized(StringConcatFactory.class);
2358
2359 // Emit a warning if java.io.tmpdir is set via the command line
2360 // to a directory that doesn't exist
2361 if (SystemProps.isBadIoTmpdir()) {
2362 System.err.println("WARNING: java.io.tmpdir directory does not exist");
2363 }
2364
2365 String smProp = System.getProperty("java.security.manager");
2366 boolean needWarning = false;
2367 if (smProp != null) {
2368 switch (smProp) {
2369 case "disallow":
2370 allowSecurityManager = NEVER;
2371 break;
2372 case "allow":
2373 allowSecurityManager = MAYBE;
2374 break;
2375 case "":
2376 case "default":
2377 implSetSecurityManager(new SecurityManager());
2378 allowSecurityManager = MAYBE;
2379 needWarning = true;
2380 break;
2381 default:
2382 try {
2383 ClassLoader cl = ClassLoader.getBuiltinAppClassLoader();
2384 Class<?> c = Class.forName(smProp, false, cl);
2385 Constructor<?> ctor = c.getConstructor();
2386 // Must be a public subclass of SecurityManager with
2387 // a public no-arg constructor
2388 if (!SecurityManager.class.isAssignableFrom(c) ||
2389 !Modifier.isPublic(c.getModifiers()) ||
2390 !Modifier.isPublic(ctor.getModifiers())) {
2391 throw new Error("Could not create SecurityManager: "
2392 + ctor.toString());
2393 }
2394 // custom security manager may be in non-exported package
2395 ctor.setAccessible(true);
2396 SecurityManager sm = (SecurityManager) ctor.newInstance();
2397 implSetSecurityManager(sm);
2398 needWarning = true;
2399 } catch (Exception e) {
2400 throw new InternalError("Could not create SecurityManager", e);
2401 }
2402 allowSecurityManager = MAYBE;
2403 }
2404 } else {
2405 allowSecurityManager = NEVER;
2406 }
2407
2408 if (needWarning) {
2409 System.err.println("""
2410 WARNING: A command line option has enabled the Security Manager
2411 WARNING: The Security Manager is deprecated and will be removed in a future release""");
2412 }
2413
2414 // Emit a warning if `sun.jnu.encoding` is not supported.
2415 if (notSupportedJnuEncoding != null) {
2416 System.err.println(
2417 "WARNING: The encoding of the underlying platform's" +
2418 " file system is not supported: " +
2419 notSupportedJnuEncoding);
2420 }
2421
2422 // initializing the system class loader
2423 VM.initLevel(3);
2424
2425 // system class loader initialized
2426 ClassLoader scl = ClassLoader.initSystemClassLoader();
2427
2428 // set TCCL
2429 Thread.currentThread().setContextClassLoader(scl);
2430
2431 // system is fully initialized
2432 VM.initLevel(4);
2433 }
2434
2435 private static void setJavaLangAccess() {
2436 // Allow privileged classes outside of java.lang
2437 SharedSecrets.setJavaLangAccess(new JavaLangAccess() {
2438 public List<Method> getDeclaredPublicMethods(Class<?> klass, String name, Class<?>... parameterTypes) {
2439 return klass.getDeclaredPublicMethods(name, parameterTypes);
2440 }
2441 public Method findMethod(Class<?> klass, boolean publicOnly, String name, Class<?>... parameterTypes) {
2442 return klass.findMethod(publicOnly, name, parameterTypes);
2443 }
2444 public jdk.internal.reflect.ConstantPool getConstantPool(Class<?> klass) {
2445 return klass.getConstantPool();
2446 }
2447 public boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType) {
2448 return klass.casAnnotationType(oldType, newType);
2449 }
2450 public AnnotationType getAnnotationType(Class<?> klass) {
2451 return klass.getAnnotationType();
2452 }
2453 public Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap(Class<?> klass) {
2454 return klass.getDeclaredAnnotationMap();
2455 }
2456 public byte[] getRawClassAnnotations(Class<?> klass) {
2457 return klass.getRawAnnotations();
2458 }
2459 public byte[] getRawClassTypeAnnotations(Class<?> klass) {
2460 return klass.getRawTypeAnnotations();
2461 }
2462 public byte[] getRawExecutableTypeAnnotations(Executable executable) {
2463 return Class.getExecutableTypeAnnotationBytes(executable);
2464 }
2465 public <E extends Enum<E>>
2466 E[] getEnumConstantsShared(Class<E> klass) {
2467 return klass.getEnumConstantsShared();
2468 }
2469 public void blockedOn(Interruptible b) {
2470 Thread.currentThread().blockedOn(b);
2471 }
2472 public void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook) {
2473 Shutdown.add(slot, registerShutdownInProgress, hook);
2474 }
2475 public Thread newThreadWithAcc(Runnable target, @SuppressWarnings("removal") AccessControlContext acc) {
2476 return new Thread(target, acc);
2477 }
2478 @SuppressWarnings("removal")
2479 public void invokeFinalize(Object o) throws Throwable {
2480 o.finalize();
2481 }
2482 public ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap(ClassLoader cl) {
2483 return cl.createOrGetClassLoaderValueMap();
2484 }
2485 public Class<?> defineClass(ClassLoader loader, String name, byte[] b, ProtectionDomain pd, String source) {
2486 return ClassLoader.defineClass1(loader, name, b, 0, b.length, pd, source);
2487 }
2488 public Class<?> defineClass(ClassLoader loader, Class<?> lookup, String name, byte[] b, ProtectionDomain pd,
2489 boolean initialize, int flags, Object classData) {
2490 return ClassLoader.defineClass0(loader, lookup, name, b, 0, b.length, pd, initialize, flags, classData);
2491 }
2492 public Class<?> findBootstrapClassOrNull(String name) {
2493 return ClassLoader.findBootstrapClassOrNull(name);
2494 }
2495 public Package definePackage(ClassLoader cl, String name, Module module) {
2496 return cl.definePackage(name, module);
2497 }
2498 @SuppressWarnings("removal")
2499 public void addNonExportedPackages(ModuleLayer layer) {
2500 SecurityManager.addNonExportedPackages(layer);
2501 }
2502 @SuppressWarnings("removal")
2503 public void invalidatePackageAccessCache() {
2504 SecurityManager.invalidatePackageAccessCache();
2505 }
2506 public Module defineModule(ClassLoader loader,
2507 ModuleDescriptor descriptor,
2508 URI uri) {
2509 return new Module(null, loader, descriptor, uri);
2510 }
2511 public Module defineUnnamedModule(ClassLoader loader) {
2512 return new Module(loader);
2513 }
2514 public void addReads(Module m1, Module m2) {
2515 m1.implAddReads(m2);
2516 }
2517 public void addReadsAllUnnamed(Module m) {
2518 m.implAddReadsAllUnnamed();
2519 }
2520 public void addExports(Module m, String pn) {
2521 m.implAddExports(pn);
2522 }
2523 public void addExports(Module m, String pn, Module other) {
2524 m.implAddExports(pn, other);
2525 }
2526 public void addExportsToAllUnnamed(Module m, String pn) {
2527 m.implAddExportsToAllUnnamed(pn);
2528 }
2529 public void addOpens(Module m, String pn, Module other) {
2530 m.implAddOpens(pn, other);
2531 }
2532 public void addOpensToAllUnnamed(Module m, String pn) {
2533 m.implAddOpensToAllUnnamed(pn);
2534 }
2535 public void addOpensToAllUnnamed(Module m, Set<String> concealedPackages, Set<String> exportedPackages) {
2536 m.implAddOpensToAllUnnamed(concealedPackages, exportedPackages);
2537 }
2538 public void addUses(Module m, Class<?> service) {
2539 m.implAddUses(service);
2540 }
2541 public boolean isReflectivelyExported(Module m, String pn, Module other) {
2542 return m.isReflectivelyExported(pn, other);
2543 }
2544 public boolean isReflectivelyOpened(Module m, String pn, Module other) {
2545 return m.isReflectivelyOpened(pn, other);
2546 }
2547 public Module addEnableNativeAccess(Module m) {
2548 return m.implAddEnableNativeAccess();
2549 }
2550 public boolean addEnableNativeAccess(ModuleLayer layer, String name) {
2551 return layer.addEnableNativeAccess(name);
2552 }
2553 public void addEnableNativeAccessToAllUnnamed() {
2554 Module.implAddEnableNativeAccessToAllUnnamed();
2555 }
2556 public void ensureNativeAccess(Module m, Class<?> owner, String methodName, Class<?> currentClass, boolean jni) {
2557 m.ensureNativeAccess(owner, methodName, currentClass, jni);
2558 }
2559 public ServicesCatalog getServicesCatalog(ModuleLayer layer) {
2560 return layer.getServicesCatalog();
2561 }
2562 public void bindToLoader(ModuleLayer layer, ClassLoader loader) {
2563 layer.bindToLoader(loader);
2564 }
2565 public Stream<ModuleLayer> layers(ModuleLayer layer) {
2566 return layer.layers();
2567 }
2568 public Stream<ModuleLayer> layers(ClassLoader loader) {
2569 return ModuleLayer.layers(loader);
2570 }
2571
2572 public int countPositives(byte[] bytes, int offset, int length) {
2573 return StringCoding.countPositives(bytes, offset, length);
2574 }
2575 public int countNonZeroAscii(String s) {
2576 return StringCoding.countNonZeroAscii(s);
2577 }
2578 public String newStringNoRepl(byte[] bytes, Charset cs) throws CharacterCodingException {
2579 return String.newStringNoRepl(bytes, cs);
2580 }
2581 public char getUTF16Char(byte[] bytes, int index) {
2582 return StringUTF16.getChar(bytes, index);
2583 }
2584 public void putCharUTF16(byte[] bytes, int index, int ch) {
2585 StringUTF16.putChar(bytes, index, ch);
2586 }
2587 public byte[] getBytesNoRepl(String s, Charset cs) throws CharacterCodingException {
2588 return String.getBytesNoRepl(s, cs);
2589 }
2590
2591 public String newStringUTF8NoRepl(byte[] bytes, int off, int len) {
2592 return String.newStringUTF8NoRepl(bytes, off, len, true);
2593 }
2594
2595 public byte[] getBytesUTF8NoRepl(String s) {
2596 return String.getBytesUTF8NoRepl(s);
2597 }
2598
2599 public void inflateBytesToChars(byte[] src, int srcOff, char[] dst, int dstOff, int len) {
2600 StringLatin1.inflate(src, srcOff, dst, dstOff, len);
2601 }
2602
2603 public int decodeASCII(byte[] src, int srcOff, char[] dst, int dstOff, int len) {
2604 return String.decodeASCII(src, srcOff, dst, dstOff, len);
2605 }
2606
2607 public int encodeASCII(char[] src, int srcOff, byte[] dst, int dstOff, int len) {
2608 return StringCoding.implEncodeAsciiArray(src, srcOff, dst, dstOff, len);
2609 }
2610
2611 public InputStream initialSystemIn() {
2612 return initialIn;
2613 }
2614
2615 public PrintStream initialSystemErr() {
2616 return initialErr;
2617 }
2618
2619 public void setCause(Throwable t, Throwable cause) {
2620 t.setCause(cause);
2621 }
2622
2623 public ProtectionDomain protectionDomain(Class<?> c) {
2624 return c.protectionDomain();
2625 }
2626
2627 public MethodHandle stringConcatHelper(String name, MethodType methodType) {
2628 return StringConcatHelper.lookupStatic(name, methodType);
2629 }
2630
2631 public long stringConcatInitialCoder() {
2632 return StringConcatHelper.initialCoder();
2633 }
2634
2635 public long stringConcatMix(long lengthCoder, String constant) {
2636 return StringConcatHelper.mix(lengthCoder, constant);
2637 }
2638
2639 public long stringConcatMix(long lengthCoder, char value) {
2640 return StringConcatHelper.mix(lengthCoder, value);
2641 }
2642
2643 public Object stringConcat1(String[] constants) {
2644 return new StringConcatHelper.Concat1(constants);
2645 }
2646
2647 public byte stringInitCoder() {
2648 return String.COMPACT_STRINGS ? String.LATIN1 : String.UTF16;
2649 }
2650
2651 public byte stringCoder(String str) {
2652 return str.coder();
2653 }
2654
2655 public int getCharsLatin1(long i, int index, byte[] buf) {
2656 return StringLatin1.getChars(i, index, buf);
2657 }
2658
2659 public int getCharsUTF16(long i, int index, byte[] buf) {
2660 return StringUTF16.getChars(i, index, buf);
2661 }
2662
2663 public String join(String prefix, String suffix, String delimiter, String[] elements, int size) {
2664 return String.join(prefix, suffix, delimiter, elements, size);
2665 }
2666
2667 public String concat(String prefix, Object value, String suffix) {
2668 return StringConcatHelper.concat(prefix, value, suffix);
2669 }
2670
2671 public Object classData(Class<?> c) {
2672 return c.getClassData();
2673 }
2674
2675 @Override
2676 public NativeLibraries nativeLibrariesFor(ClassLoader loader) {
2677 return ClassLoader.nativeLibrariesFor(loader);
2678 }
2679
2680 @Override
2681 public void exit(int statusCode) {
2682 Shutdown.exit(statusCode);
2683 }
2684
2685 public Thread[] getAllThreads() {
2686 return Thread.getAllThreads();
2687 }
2688
2689 public ThreadContainer threadContainer(Thread thread) {
2690 return thread.threadContainer();
2691 }
2692
2693 public void start(Thread thread, ThreadContainer container) {
2694 thread.start(container);
2695 }
2696
2697 public StackableScope headStackableScope(Thread thread) {
2698 return thread.headStackableScopes();
2699 }
2700
2701 public void setHeadStackableScope(StackableScope scope) {
2702 Thread.setHeadStackableScope(scope);
2703 }
2704
2705 public Thread currentCarrierThread() {
2706 return Thread.currentCarrierThread();
2707 }
2708
2709 public <T> T getCarrierThreadLocal(CarrierThreadLocal<T> local) {
2710 return ((ThreadLocal<T>)local).getCarrierThreadLocal();
2711 }
2712
2713 public <T> void setCarrierThreadLocal(CarrierThreadLocal<T> local, T value) {
2714 ((ThreadLocal<T>)local).setCarrierThreadLocal(value);
2715 }
2716
2717 public void removeCarrierThreadLocal(CarrierThreadLocal<?> local) {
2718 ((ThreadLocal<?>)local).removeCarrierThreadLocal();
2719 }
2720
2721 public boolean isCarrierThreadLocalPresent(CarrierThreadLocal<?> local) {
2722 return ((ThreadLocal<?>)local).isCarrierThreadLocalPresent();
2723 }
2724
2725 public Object[] scopedValueCache() {
2726 return Thread.scopedValueCache();
2727 }
2728
2729 public void setScopedValueCache(Object[] cache) {
2730 Thread.setScopedValueCache(cache);
2731 }
2732
2733 public Object scopedValueBindings() {
2734 return Thread.scopedValueBindings();
2735 }
2736
2737 public Continuation getContinuation(Thread thread) {
2738 return thread.getContinuation();
2739 }
2740
2741 public void setContinuation(Thread thread, Continuation continuation) {
2742 thread.setContinuation(continuation);
2743 }
2744
2745 public ContinuationScope virtualThreadContinuationScope() {
2746 return VirtualThread.continuationScope();
2747 }
2748
2749 public void parkVirtualThread() {
2750 Thread thread = Thread.currentThread();
2751 if (thread instanceof BaseVirtualThread vthread) {
2752 vthread.park();
2753 } else {
2754 throw new WrongThreadException();
2755 }
2756 }
2757
2758 public void parkVirtualThread(long nanos) {
2759 Thread thread = Thread.currentThread();
2760 if (thread instanceof BaseVirtualThread vthread) {
2761 vthread.parkNanos(nanos);
2762 } else {
2763 throw new WrongThreadException();
2764 }
2765 }
2766
2767 public void unparkVirtualThread(Thread thread) {
2768 if (thread instanceof BaseVirtualThread vthread) {
2769 vthread.unpark();
2770 } else {
2771 throw new WrongThreadException();
2772 }
2773 }
2774
2775 public Executor virtualThreadDefaultScheduler() {
2776 return VirtualThread.defaultScheduler();
2777 }
2778
2779 public StackWalker newStackWalkerInstance(Set<StackWalker.Option> options,
2780 ContinuationScope contScope,
2781 Continuation continuation) {
2782 return StackWalker.newInstance(options, null, contScope, continuation);
2783 }
2784
2785 public int classFileFormatVersion(Class<?> clazz) {
2786 return clazz.getClassFileVersion();
2787 }
2788
2789 public String getLoaderNameID(ClassLoader loader) {
2790 return loader != null ? loader.nameAndId() : "null";
2791 }
2792
2793 @Override
2794 public void copyToSegmentRaw(String string, MemorySegment segment, long offset) {
2795 string.copyToSegmentRaw(segment, offset);
2796 }
2797
2798 @Override
2799 public boolean bytesCompatible(String string, Charset charset) {
2800 return string.bytesCompatible(charset);
2801 }
2802
2803 @Override
2804 public boolean allowSecurityManager() {
2805 return System.allowSecurityManager();
2806 }
2807 });
2808 }
2809 }