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