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.IntrinsicCandidate;
30 import jdk.internal.vm.annotation.Stable;
31
32 import java.lang.constant.Constable;
33 import java.lang.constant.DynamicConstantDesc;
34 import java.util.Arrays;
35 import java.util.HashMap;
36 import java.util.Locale;
37 import java.util.Map;
38 import java.util.Objects;
39 import java.util.Optional;
40
41 import static java.lang.constant.ConstantDescs.BSM_EXPLICIT_CAST;
42 import static java.lang.constant.ConstantDescs.CD_char;
43 import static java.lang.constant.ConstantDescs.DEFAULT_NAME;
44
45 /**
46 * The {@code Character} class is the {@linkplain
47 * java.lang##wrapperClass wrapper class} for values of the primitive
48 * type {@code char}. An object of type {@code Character} contains a
151 * surrogate ranges as undefined characters. For example,
152 * {@code Character.isLetter('\u005CuD840')} returns {@code false}, even though
153 * this specific value if followed by any low-surrogate value in a string
154 * would represent a letter.
155 *
156 * <li>The methods that accept an {@code int} value support all
157 * Unicode characters, including supplementary characters. For
158 * example, {@code Character.isLetter(0x2F81A)} returns
159 * {@code true} because the code point value represents a letter
160 * (a CJK ideograph).
161 * </ul>
162 *
163 * <p>In the Java SE API documentation, <em>Unicode code point</em> is
164 * used for character values in the range between U+0000 and U+10FFFF,
165 * and <em>Unicode code unit</em> is used for 16-bit
166 * {@code char} values that are code units of the <em>UTF-16</em>
167 * encoding. For more information on Unicode terminology, refer to the
168 * <a href="http://www.unicode.org/glossary/">Unicode Glossary</a>.
169 *
170 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
171 * class; programmers should treat instances that are
172 * {@linkplain #equals(Object) equal} as interchangeable and should not
173 * use instances for synchronization, or unpredictable behavior may
174 * occur. For example, in a future release, synchronization may fail.
175 *
176 * @spec https://www.unicode.org/reports/tr27 Unicode 3.1.0
177 * @author Lee Boynton
178 * @author Guy Steele
179 * @author Akira Tanaka
180 * @author Martin Buchholz
181 * @author Ulf Zibis
182 * @since 1.0
183 */
184 @jdk.internal.ValueBased
185 public final
186 class Character implements java.io.Serializable, Comparable<Character>, Constable {
187 /**
188 * The minimum radix available for conversion to and from strings.
189 * The constant value of this field is the smallest value permitted
190 * for the radix argument in radix-conversion methods such as the
191 * {@code digit} method, the {@code forDigit} method, and the
192 * {@code toString} method of class {@code Integer}.
193 *
194 * @see Character#digit(char, int)
195 * @see Character#forDigit(int, int)
196 * @see Integer#toString(int, int)
197 * @see Integer#valueOf(String)
198 */
199 public static final int MIN_RADIX = 2;
200
201 /**
202 * The maximum radix available for conversion to and from strings.
203 * The constant value of this field is the largest value permitted
204 * for the radix argument in radix-conversion methods such as the
205 * {@code digit} method, the {@code forDigit} method, and the
206 * {@code toString} method of class {@code Integer}.
9262 }
9263
9264 /**
9265 * Returns a {@code Character} instance representing the specified
9266 * {@code char} value.
9267 * If a new {@code Character} instance is not required, this method
9268 * should generally be used in preference to the constructor
9269 * {@link #Character(char)}, as this method is likely to yield
9270 * significantly better space and time performance by caching
9271 * frequently requested values.
9272 *
9273 * This method will always cache values in the range {@code
9274 * '\u005Cu0000'} to {@code '\u005Cu007F'}, inclusive, and may
9275 * cache other values outside of this range.
9276 *
9277 * @param c a char value.
9278 * @return a {@code Character} instance representing {@code c}.
9279 * @since 1.5
9280 */
9281 @IntrinsicCandidate
9282 public static Character valueOf(char c) {
9283 if (c <= 127) { // must cache
9284 return CharacterCache.cache[(int)c];
9285 }
9286 return new Character(c);
9287 }
9288
9289 /**
9290 * Returns the value of this {@code Character} object.
9291 * @return the primitive {@code char} value represented by
9292 * this object.
9293 */
9294 @IntrinsicCandidate
9295 public char charValue() {
9296 return value;
9297 }
9298
9299 /**
9300 * Returns a hash code for this {@code Character}; equal to the result
9301 * of invoking {@code charValue()}.
|
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.value.DeserializeConstructor;
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.Arrays;
36 import java.util.HashMap;
37 import java.util.Locale;
38 import java.util.Map;
39 import java.util.Objects;
40 import java.util.Optional;
41
42 import static java.lang.constant.ConstantDescs.BSM_EXPLICIT_CAST;
43 import static java.lang.constant.ConstantDescs.CD_char;
44 import static java.lang.constant.ConstantDescs.DEFAULT_NAME;
45
46 /**
47 * The {@code Character} class is the {@linkplain
48 * java.lang##wrapperClass wrapper class} for values of the primitive
49 * type {@code char}. An object of type {@code Character} contains a
152 * surrogate ranges as undefined characters. For example,
153 * {@code Character.isLetter('\u005CuD840')} returns {@code false}, even though
154 * this specific value if followed by any low-surrogate value in a string
155 * would represent a letter.
156 *
157 * <li>The methods that accept an {@code int} value support all
158 * Unicode characters, including supplementary characters. For
159 * example, {@code Character.isLetter(0x2F81A)} returns
160 * {@code true} because the code point value represents a letter
161 * (a CJK ideograph).
162 * </ul>
163 *
164 * <p>In the Java SE API documentation, <em>Unicode code point</em> is
165 * used for character values in the range between U+0000 and U+10FFFF,
166 * and <em>Unicode code unit</em> is used for 16-bit
167 * {@code char} values that are code units of the <em>UTF-16</em>
168 * encoding. For more information on Unicode terminology, refer to the
169 * <a href="http://www.unicode.org/glossary/">Unicode Glossary</a>.
170 *
171 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
172 * class; programmers should treat instances that are {@linkplain #equals(Object) equal}
173 * as interchangeable and should not use instances for synchronization, mutexes, or
174 * with {@linkplain java.lang.ref.Reference object references}.
175 *
176 * <div class="preview-block">
177 * <div class="preview-comment">
178 * When preview features are enabled, {@code Character} is a {@linkplain Class#isValue value class}.
179 * Use of value class instances for synchronization, mutexes, or with
180 * {@linkplain java.lang.ref.Reference object references} result in
181 * {@link IdentityException}.
182 * </div>
183 * </div>
184 *
185 * @spec https://www.unicode.org/reports/tr27 Unicode 3.1.0
186 * @author Lee Boynton
187 * @author Guy Steele
188 * @author Akira Tanaka
189 * @author Martin Buchholz
190 * @author Ulf Zibis
191 * @since 1.0
192 */
193 @jdk.internal.MigratedValueClass
194 @jdk.internal.ValueBased
195 public final class Character implements java.io.Serializable, Comparable<Character>, Constable {
196 /**
197 * The minimum radix available for conversion to and from strings.
198 * The constant value of this field is the smallest value permitted
199 * for the radix argument in radix-conversion methods such as the
200 * {@code digit} method, the {@code forDigit} method, and the
201 * {@code toString} method of class {@code Integer}.
202 *
203 * @see Character#digit(char, int)
204 * @see Character#forDigit(int, int)
205 * @see Integer#toString(int, int)
206 * @see Integer#valueOf(String)
207 */
208 public static final int MIN_RADIX = 2;
209
210 /**
211 * The maximum radix available for conversion to and from strings.
212 * The constant value of this field is the largest value permitted
213 * for the radix argument in radix-conversion methods such as the
214 * {@code digit} method, the {@code forDigit} method, and the
215 * {@code toString} method of class {@code Integer}.
9271 }
9272
9273 /**
9274 * Returns a {@code Character} instance representing the specified
9275 * {@code char} value.
9276 * If a new {@code Character} instance is not required, this method
9277 * should generally be used in preference to the constructor
9278 * {@link #Character(char)}, as this method is likely to yield
9279 * significantly better space and time performance by caching
9280 * frequently requested values.
9281 *
9282 * This method will always cache values in the range {@code
9283 * '\u005Cu0000'} to {@code '\u005Cu007F'}, inclusive, and may
9284 * cache other values outside of this range.
9285 *
9286 * @param c a char value.
9287 * @return a {@code Character} instance representing {@code c}.
9288 * @since 1.5
9289 */
9290 @IntrinsicCandidate
9291 @DeserializeConstructor
9292 public static Character valueOf(char c) {
9293 if (c <= 127) { // must cache
9294 return CharacterCache.cache[(int)c];
9295 }
9296 return new Character(c);
9297 }
9298
9299 /**
9300 * Returns the value of this {@code Character} object.
9301 * @return the primitive {@code char} value represented by
9302 * this object.
9303 */
9304 @IntrinsicCandidate
9305 public char charValue() {
9306 return value;
9307 }
9308
9309 /**
9310 * Returns a hash code for this {@code Character}; equal to the result
9311 * of invoking {@code charValue()}.
|