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
26 package java.lang;
27
28 import jdk.internal.misc.CDS;
29 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
30 import jdk.internal.vm.annotation.IntrinsicCandidate;
31 import jdk.internal.vm.annotation.Stable;
32
33 import java.lang.constant.Constable;
34 import java.lang.constant.DynamicConstantDesc;
35 import java.util.Optional;
36
37 import static java.lang.constant.ConstantDescs.BSM_EXPLICIT_CAST;
38 import static java.lang.constant.ConstantDescs.CD_short;
39 import static java.lang.constant.ConstantDescs.DEFAULT_NAME;
40
41 /**
42 * The {@code Short} class is the {@linkplain
43 * java.lang##wrapperClass wrapper class} for values of the primitive
44 * type {@code short}. An object of type {@code Short} contains a
45 * single field whose type is {@code short}.
46 *
47 * <p>In addition, this class provides several methods for converting
48 * a {@code short} to a {@code String} and a {@code String} to a
49 * {@code short}, as well as other constants and methods useful when
50 * dealing with a {@code short}.
51 *
52 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
53 * class; programmers should treat instances that are
54 * {@linkplain #equals(Object) equal} as interchangeable and should not
55 * use instances for synchronization, or unpredictable behavior may
56 * occur. For example, in a future release, synchronization may fail.
57 *
58 * @see java.lang.Number
59 * @since 1.1
60 */
61 @jdk.internal.ValueBased
62 public final class Short extends Number implements Comparable<Short>, Constable {
63
64 /**
65 * A constant holding the minimum value a {@code short} can
66 * have, -2<sup>15</sup>.
67 */
68 public static final short MIN_VALUE = -32768;
69
70 /**
71 * A constant holding the maximum value a {@code short} can
72 * have, 2<sup>15</sup>-1.
73 */
74 public static final short MAX_VALUE = 32767;
75
76 /**
77 * The {@code Class} instance representing the primitive type
78 * {@code short}.
79 */
80 public static final Class<Short> TYPE = Class.getPrimitiveClass("short");
222 * Returns an {@link Optional} containing the nominal descriptor for this
223 * instance.
224 *
225 * @return an {@link Optional} describing the {@linkplain Short} instance
226 * @since 15
227 */
228 @Override
229 public Optional<DynamicConstantDesc<Short>> describeConstable() {
230 return Optional.of(DynamicConstantDesc.ofNamed(BSM_EXPLICIT_CAST, DEFAULT_NAME, CD_short, intValue()));
231 }
232
233 @AOTSafeClassInitializer
234 private static final class ShortCache {
235 private ShortCache() {}
236
237 @Stable
238 static final Short[] cache;
239 static Short[] archivedCache;
240
241 static {
242 int size = -(-128) + 127 + 1;
243
244 // Load and use the archived cache if it exists
245 CDS.initializeFromArchive(ShortCache.class);
246 if (archivedCache == null) {
247 Short[] c = new Short[size];
248 short value = -128;
249 for(int i = 0; i < size; i++) {
250 c[i] = new Short(value++);
251 }
252 archivedCache = c;
253 }
254 cache = archivedCache;
255 assert cache.length == size;
256 }
257 }
258
259 /**
260 * Returns a {@code Short} instance representing the specified
261 * {@code short} value.
262 * If a new {@code Short} instance is not required, this method
263 * should generally be used in preference to the constructor
264 * {@link #Short(short)}, as this method is likely to yield
265 * significantly better space and time performance by caching
266 * frequently requested values.
267 *
268 * This method will always cache values in the range -128 to 127,
269 * inclusive, and may cache other values outside of this range.
270 *
271 * @param s a short value.
272 * @return a {@code Short} instance representing {@code s}.
273 * @since 1.5
274 */
275 @IntrinsicCandidate
276 public static Short valueOf(short s) {
277 final int offset = 128;
278 int sAsInt = s;
279 if (sAsInt >= -128 && sAsInt <= 127) { // must cache
280 return ShortCache.cache[sAsInt + offset];
281 }
282 return new Short(s);
283 }
284
285 /**
286 * Decodes a {@code String} into a {@code Short}.
287 * Accepts decimal, hexadecimal, and octal numbers given by
288 * the following grammar:
289 *
290 * <blockquote>
291 * <dl>
292 * <dt><i>DecodableString:</i>
293 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
294 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
295 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
296 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
297 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
298 *
299 * <dt><i>Sign:</i>
300 * <dd>{@code -}
|
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
26 package java.lang;
27
28 import jdk.internal.misc.CDS;
29 import jdk.internal.misc.PreviewFeatures;
30 import jdk.internal.value.DeserializeConstructor;
31 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
32 import jdk.internal.vm.annotation.IntrinsicCandidate;
33 import jdk.internal.vm.annotation.Stable;
34
35 import java.lang.constant.Constable;
36 import java.lang.constant.DynamicConstantDesc;
37 import java.util.Optional;
38
39 import static java.lang.constant.ConstantDescs.BSM_EXPLICIT_CAST;
40 import static java.lang.constant.ConstantDescs.CD_short;
41 import static java.lang.constant.ConstantDescs.DEFAULT_NAME;
42
43 /**
44 * The {@code Short} class is the {@linkplain
45 * java.lang##wrapperClass wrapper class} for values of the primitive
46 * type {@code short}. An object of type {@code Short} contains a
47 * single field whose type is {@code short}.
48 *
49 * <p>In addition, this class provides several methods for converting
50 * a {@code short} to a {@code String} and a {@code String} to a
51 * {@code short}, as well as other constants and methods useful when
52 * dealing with a {@code short}.
53 *
54 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
55 * class; programmers should treat instances that are {@linkplain #equals(Object) equal}
56 * as interchangeable and should not use instances for synchronization, mutexes, or
57 * with {@linkplain java.lang.ref.Reference object references}.
58 *
59 * <div class="preview-block">
60 * <div class="preview-comment">
61 * When preview features are enabled, {@code Short} is a {@linkplain Class#isValue value class}.
62 * Use of value class instances for synchronization, mutexes, or with
63 * {@linkplain java.lang.ref.Reference object references} result in
64 * {@link IdentityException}.
65 * </div>
66 * </div>
67 *
68 * @see java.lang.Number
69 * @since 1.1
70 */
71 @jdk.internal.MigratedValueClass
72 @jdk.internal.ValueBased
73 public final class Short extends Number implements Comparable<Short>, Constable {
74
75 /**
76 * A constant holding the minimum value a {@code short} can
77 * have, -2<sup>15</sup>.
78 */
79 public static final short MIN_VALUE = -32768;
80
81 /**
82 * A constant holding the maximum value a {@code short} can
83 * have, 2<sup>15</sup>-1.
84 */
85 public static final short MAX_VALUE = 32767;
86
87 /**
88 * The {@code Class} instance representing the primitive type
89 * {@code short}.
90 */
91 public static final Class<Short> TYPE = Class.getPrimitiveClass("short");
233 * Returns an {@link Optional} containing the nominal descriptor for this
234 * instance.
235 *
236 * @return an {@link Optional} describing the {@linkplain Short} instance
237 * @since 15
238 */
239 @Override
240 public Optional<DynamicConstantDesc<Short>> describeConstable() {
241 return Optional.of(DynamicConstantDesc.ofNamed(BSM_EXPLICIT_CAST, DEFAULT_NAME, CD_short, intValue()));
242 }
243
244 @AOTSafeClassInitializer
245 private static final class ShortCache {
246 private ShortCache() {}
247
248 @Stable
249 static final Short[] cache;
250 static Short[] archivedCache;
251
252 static {
253 if (!PreviewFeatures.isEnabled()) {
254 int size = -(-128) + 127 + 1;
255
256 // Load and use the archived cache if it exists
257 CDS.initializeFromArchive(ShortCache.class);
258 if (archivedCache == null) {
259 Short[] c = new Short[size];
260 short value = -128;
261 for(int i = 0; i < size; i++) {
262 c[i] = new Short(value++);
263 }
264 archivedCache = c;
265 }
266 cache = archivedCache;
267 assert cache.length == size;
268 } else {
269 cache = null;
270 assert archivedCache == null;
271 }
272 }
273 }
274
275 /**
276 * Returns a {@code Short} instance representing the specified
277 * {@code short} value.
278 * <div class="preview-block">
279 * <div class="preview-comment">
280 * <p>
281 * - When preview features are NOT enabled, {@code Short} is an identity class.
282 * If a new {@code Short} instance is not required, this method
283 * should generally be used in preference to the constructor
284 * {@link #Short(short)}, as this method is likely to yield
285 * significantly better space and time performance by caching
286 * frequently requested values.
287 * This method will always cache values in the range -128 to 127,
288 * inclusive, and may cache other values outside of this range.
289 * </p>
290 * <p>
291 * - When preview features are enabled, {@code Short} is a {@linkplain Class#isValue value class}.
292 * The {@code valueOf} behavior is the same as invoking the constructor,
293 * whether cached or not.
294 * </p>
295 * </div>
296 * </div>
297 *
298 * @param s a short value.
299 * @return a {@code Short} instance representing {@code s}.
300 * @since 1.5
301 */
302 @IntrinsicCandidate
303 @DeserializeConstructor
304 public static Short valueOf(short s) {
305 if (!PreviewFeatures.isEnabled()) {
306 final int offset = 128;
307 int sAsInt = s;
308 if (sAsInt >= -128 && sAsInt <= 127) { // must cache
309 return ShortCache.cache[sAsInt + offset];
310 }
311 }
312 return new Short(s);
313 }
314
315 /**
316 * Decodes a {@code String} into a {@code Short}.
317 * Accepts decimal, hexadecimal, and octal numbers given by
318 * the following grammar:
319 *
320 * <blockquote>
321 * <dl>
322 * <dt><i>DecodableString:</i>
323 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
324 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
325 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
326 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
327 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
328 *
329 * <dt><i>Sign:</i>
330 * <dd>{@code -}
|