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
26 package java.util;
27
28 import jdk.internal.util.Preconditions;
29 import jdk.internal.vm.annotation.ForceInline;
30
31 import java.util.function.Supplier;
32
33 /**
34 * This class consists of {@code static} utility methods for operating
35 * on objects, or checking certain conditions before operation. These utilities
36 * include {@code null}-safe or {@code null}-tolerant methods for computing the
37 * hash code of an object, returning a string for an object, comparing two
38 * objects, and checking if indexes or sub-range values are out of bounds.
39 *
40 * @since 1.7
41 */
42 public final class Objects {
43 private Objects() {
44 throw new AssertionError("No java.util.Objects instances for you!");
45 }
46
47 /**
48 * Returns {@code true} if the arguments are equal to each other
49 * and {@code false} otherwise.
171 *
172 * @implNote
173 * This method constructs a string for an object without calling
174 * any overridable methods of the object.
175 *
176 * @implSpec
177 * The method returns a string equivalent to:<br>
178 * {@code o.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(o))}
179 *
180 * @param o an object
181 * @throws NullPointerException if the argument is null
182 * @see Object#toString
183 * @see System#identityHashCode(Object)
184 * @since 19
185 */
186 public static String toIdentityString(Object o) {
187 requireNonNull(o);
188 return o.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(o));
189 }
190
191 /**
192 * Returns 0 if the arguments are identical and {@code
193 * c.compare(a, b)} otherwise.
194 * Consequently, if both arguments are {@code null} 0
195 * is returned.
196 *
197 * <p>Note that if one of the arguments is {@code null}, a {@code
198 * NullPointerException} may or may not be thrown depending on
199 * what ordering policy, if any, the {@link Comparator Comparator}
200 * chooses to have for {@code null} values.
201 *
202 * @param <T> the type of the objects being compared
203 * @param a an object
204 * @param b an object to be compared with {@code a}
205 * @param c the {@code Comparator} to compare the first two arguments
206 * @return 0 if the arguments are identical and {@code
207 * c.compare(a, b)} otherwise.
208 * @see Comparable
209 * @see Comparator
210 */
420 * inequalities is true:
421 * <ul>
422 * <li>{@code fromIndex < 0}</li>
423 * <li>{@code size < 0}</li>
424 * <li>{@code fromIndex + size > length}, taking into account integer overflow</li>
425 * <li>{@code length < 0}, which is implied from the former inequalities</li>
426 * </ul>
427 *
428 * @param fromIndex the lower-bound (inclusive) of the sub-interval
429 * @param size the size of the sub-range
430 * @param length the upper-bound (exclusive) of the range
431 * @return {@code fromIndex} if the sub-range within bounds of the range
432 * @throws IndexOutOfBoundsException if the sub-range is out of bounds
433 * @since 9
434 */
435 public static
436 int checkFromIndexSize(int fromIndex, int size, int length) {
437 return Preconditions.checkFromIndexSize(fromIndex, size, length, null);
438 }
439
440 /**
441 * Checks if the {@code index} is within the bounds of the range from
442 * {@code 0} (inclusive) to {@code length} (exclusive).
443 *
444 * <p>The {@code index} is defined to be out of bounds if any of the
445 * following inequalities is true:
446 * <ul>
447 * <li>{@code index < 0}</li>
448 * <li>{@code index >= length}</li>
449 * <li>{@code length < 0}, which is implied from the former inequalities</li>
450 * </ul>
451 *
452 * @param index the index
453 * @param length the upper-bound (exclusive) of the range
454 * @return {@code index} if it is within bounds of the range
455 * @throws IndexOutOfBoundsException if the {@code index} is out of bounds
456 * @since 16
457 */
458 @ForceInline
459 public static
|
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
26 package java.util;
27
28 import jdk.internal.util.Preconditions;
29 import jdk.internal.vm.annotation.ForceInline;
30 import jdk.internal.misc.Unsafe;
31
32 import java.util.function.Supplier;
33
34 /**
35 * This class consists of {@code static} utility methods for operating
36 * on objects, or checking certain conditions before operation. These utilities
37 * include {@code null}-safe or {@code null}-tolerant methods for computing the
38 * hash code of an object, returning a string for an object, comparing two
39 * objects, and checking if indexes or sub-range values are out of bounds.
40 *
41 * @since 1.7
42 */
43 public final class Objects {
44 private Objects() {
45 throw new AssertionError("No java.util.Objects instances for you!");
46 }
47
48 /**
49 * Returns {@code true} if the arguments are equal to each other
50 * and {@code false} otherwise.
172 *
173 * @implNote
174 * This method constructs a string for an object without calling
175 * any overridable methods of the object.
176 *
177 * @implSpec
178 * The method returns a string equivalent to:<br>
179 * {@code o.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(o))}
180 *
181 * @param o an object
182 * @throws NullPointerException if the argument is null
183 * @see Object#toString
184 * @see System#identityHashCode(Object)
185 * @since 19
186 */
187 public static String toIdentityString(Object o) {
188 requireNonNull(o);
189 return o.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(o));
190 }
191
192 /**
193 * Checks that the specified object reference is an identity object.
194 *
195 * @param obj the object reference to check for identity
196 * @param <T> the type of the reference
197 * @return {@code obj} if {@code obj} is an identity object
198 * @throws NullPointerException if {@code obj} is {@code null}
199 * @throws IdentityException if {@code obj} is not an identity object
200 * @since Valhalla
201 */
202 @ForceInline
203 public static <T> T requireIdentity(T obj) {
204 Objects.requireNonNull(obj);
205 var cl = obj.getClass();
206 if (cl.isValue())
207 throw new IdentityException(cl);
208 return obj;
209 }
210
211 /**
212 * Checks that the specified object reference is an identity object.
213 *
214 * @param obj the object reference to check for identity
215 * @param message detail message to be used in the event that an
216 * {@code IdentityException} is thrown; may be null
217 * @param <T> the type of the reference
218 * @return {@code obj} if {@code obj} is an identity object
219 * @throws NullPointerException if {@code obj} is {@code null}
220 * @throws IdentityException if {@code obj} is not an identity object
221 * @since Valhalla
222 */
223 @ForceInline
224 public static <T> T requireIdentity(T obj, String message) {
225 Objects.requireNonNull(obj);
226 if (obj.getClass().isValue())
227 throw new IdentityException(message);
228 return obj;
229 }
230
231 /**
232 * Checks that the specified object reference is an identity object.
233 *
234 * @param obj the object reference to check for identity
235 * @param messageSupplier supplier of the detail message to be
236 * used in the event that an {@code IdentityException} is thrown; may be null
237 * @param <T> the type of the reference
238 * @return {@code obj} if {@code obj} is an identity object
239 * @throws NullPointerException if {@code obj} is {@code null}
240 * @throws IdentityException if {@code obj} is not an identity object
241 * @since Valhalla
242 */
243 @ForceInline
244 public static <T> T requireIdentity(T obj, Supplier<String> messageSupplier) {
245 Objects.requireNonNull(obj);
246 if (obj.getClass().isValue())
247 throw new IdentityException(messageSupplier == null ?
248 null : messageSupplier.get());
249 return obj;
250 }
251
252 /**
253 * Returns 0 if the arguments are identical and {@code
254 * c.compare(a, b)} otherwise.
255 * Consequently, if both arguments are {@code null} 0
256 * is returned.
257 *
258 * <p>Note that if one of the arguments is {@code null}, a {@code
259 * NullPointerException} may or may not be thrown depending on
260 * what ordering policy, if any, the {@link Comparator Comparator}
261 * chooses to have for {@code null} values.
262 *
263 * @param <T> the type of the objects being compared
264 * @param a an object
265 * @param b an object to be compared with {@code a}
266 * @param c the {@code Comparator} to compare the first two arguments
267 * @return 0 if the arguments are identical and {@code
268 * c.compare(a, b)} otherwise.
269 * @see Comparable
270 * @see Comparator
271 */
481 * inequalities is true:
482 * <ul>
483 * <li>{@code fromIndex < 0}</li>
484 * <li>{@code size < 0}</li>
485 * <li>{@code fromIndex + size > length}, taking into account integer overflow</li>
486 * <li>{@code length < 0}, which is implied from the former inequalities</li>
487 * </ul>
488 *
489 * @param fromIndex the lower-bound (inclusive) of the sub-interval
490 * @param size the size of the sub-range
491 * @param length the upper-bound (exclusive) of the range
492 * @return {@code fromIndex} if the sub-range within bounds of the range
493 * @throws IndexOutOfBoundsException if the sub-range is out of bounds
494 * @since 9
495 */
496 public static
497 int checkFromIndexSize(int fromIndex, int size, int length) {
498 return Preconditions.checkFromIndexSize(fromIndex, size, length, null);
499 }
500
501 /**
502 * Return the size of the object in the heap.
503 *
504 * @param o an object
505 * @return the objects's size
506 * @since Valhalla
507 */
508 public static long getObjectSize(Object o) {
509 return Unsafe.getUnsafe().getObjectSize(o);
510 }
511
512 /**
513 * Checks if the {@code index} is within the bounds of the range from
514 * {@code 0} (inclusive) to {@code length} (exclusive).
515 *
516 * <p>The {@code index} is defined to be out of bounds if any of the
517 * following inequalities is true:
518 * <ul>
519 * <li>{@code index < 0}</li>
520 * <li>{@code index >= length}</li>
521 * <li>{@code length < 0}, which is implied from the former inequalities</li>
522 * </ul>
523 *
524 * @param index the index
525 * @param length the upper-bound (exclusive) of the range
526 * @return {@code index} if it is within bounds of the range
527 * @throws IndexOutOfBoundsException if the {@code index} is out of bounds
528 * @since 16
529 */
530 @ForceInline
531 public static
|