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
149 * surrogate ranges as undefined characters. For example,
150 * {@code Character.isLetter('\u005CuD840')} returns {@code false}, even though
151 * this specific value if followed by any low-surrogate value in a string
152 * would represent a letter.
153 *
154 * <li>The methods that accept an {@code int} value support all
155 * Unicode characters, including supplementary characters. For
156 * example, {@code Character.isLetter(0x2F81A)} returns
157 * {@code true} because the code point value represents a letter
158 * (a CJK ideograph).
159 * </ul>
160 *
161 * <p>In the Java SE API documentation, <em>Unicode code point</em> is
162 * used for character values in the range between U+0000 and U+10FFFF,
163 * and <em>Unicode code unit</em> is used for 16-bit
164 * {@code char} values that are code units of the <em>UTF-16</em>
165 * encoding. For more information on Unicode terminology, refer to the
166 * <a href="http://www.unicode.org/glossary/">Unicode Glossary</a>.
167 *
168 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
169 * class; programmers should treat instances that are
170 * {@linkplain #equals(Object) equal} as interchangeable and should not
171 * use instances for synchronization, or unpredictable behavior may
172 * occur. For example, in a future release, synchronization may fail.
173 *
174 * @spec https://www.unicode.org/reports/tr27 Unicode 3.1.0
175 * @author Lee Boynton
176 * @author Guy Steele
177 * @author Akira Tanaka
178 * @author Martin Buchholz
179 * @author Ulf Zibis
180 * @since 1.0
181 */
182 @jdk.internal.ValueBased
183 public final
184 class Character implements java.io.Serializable, Comparable<Character>, Constable {
185 /**
186 * The minimum radix available for conversion to and from strings.
187 * The constant value of this field is the smallest value permitted
188 * for the radix argument in radix-conversion methods such as the
189 * {@code digit} method, the {@code forDigit} method, and the
190 * {@code toString} method of class {@code Integer}.
191 *
192 * @see Character#digit(char, int)
193 * @see Character#forDigit(int, int)
194 * @see Integer#toString(int, int)
195 * @see Integer#valueOf(String)
196 */
197 public static final int MIN_RADIX = 2;
198
199 /**
200 * The maximum radix available for conversion to and from strings.
201 * The constant value of this field is the largest value permitted
202 * for the radix argument in radix-conversion methods such as the
203 * {@code digit} method, the {@code forDigit} method, and the
204 * {@code toString} method of class {@code Integer}.
8997 }
8998
8999 /**
9000 * Returns a {@code Character} instance representing the specified
9001 * {@code char} value.
9002 * If a new {@code Character} instance is not required, this method
9003 * should generally be used in preference to the constructor
9004 * {@link #Character(char)}, as this method is likely to yield
9005 * significantly better space and time performance by caching
9006 * frequently requested values.
9007 *
9008 * This method will always cache values in the range {@code
9009 * '\u005Cu0000'} to {@code '\u005Cu007F'}, inclusive, and may
9010 * cache other values outside of this range.
9011 *
9012 * @param c a char value.
9013 * @return a {@code Character} instance representing {@code c}.
9014 * @since 1.5
9015 */
9016 @IntrinsicCandidate
9017 public static Character valueOf(char c) {
9018 if (c <= 127) { // must cache
9019 return CharacterCache.cache[(int)c];
9020 }
9021 return new Character(c);
9022 }
9023
9024 /**
9025 * Returns the value of this {@code Character} object.
9026 * @return the primitive {@code char} value represented by
9027 * this object.
9028 */
9029 @IntrinsicCandidate
9030 public char charValue() {
9031 return value;
9032 }
9033
9034 /**
9035 * Returns a hash code for this {@code Character}; equal to the result
9036 * 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
150 * surrogate ranges as undefined characters. For example,
151 * {@code Character.isLetter('\u005CuD840')} returns {@code false}, even though
152 * this specific value if followed by any low-surrogate value in a string
153 * would represent a letter.
154 *
155 * <li>The methods that accept an {@code int} value support all
156 * Unicode characters, including supplementary characters. For
157 * example, {@code Character.isLetter(0x2F81A)} returns
158 * {@code true} because the code point value represents a letter
159 * (a CJK ideograph).
160 * </ul>
161 *
162 * <p>In the Java SE API documentation, <em>Unicode code point</em> is
163 * used for character values in the range between U+0000 and U+10FFFF,
164 * and <em>Unicode code unit</em> is used for 16-bit
165 * {@code char} values that are code units of the <em>UTF-16</em>
166 * encoding. For more information on Unicode terminology, refer to the
167 * <a href="http://www.unicode.org/glossary/">Unicode Glossary</a>.
168 *
169 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
170 * class; programmers should treat instances that are {@linkplain #equals(Object) equal}
171 * as interchangeable and should not use instances for synchronization, mutexes, or
172 * with {@linkplain java.lang.ref.Reference object references}.
173 *
174 * <div class="preview-block">
175 * <div class="preview-comment">
176 * When preview features are enabled, {@code Character} is a {@linkplain Class#isValue value class}.
177 * Use of value class instances for synchronization, mutexes, or with
178 * {@linkplain java.lang.ref.Reference object references} result in
179 * {@link IdentityException}.
180 * </div>
181 * </div>
182 *
183 * @spec https://www.unicode.org/reports/tr27 Unicode 3.1.0
184 * @author Lee Boynton
185 * @author Guy Steele
186 * @author Akira Tanaka
187 * @author Martin Buchholz
188 * @author Ulf Zibis
189 * @since 1.0
190 */
191 @jdk.internal.MigratedValueClass
192 @jdk.internal.ValueBased
193 public final class Character implements java.io.Serializable, Comparable<Character>, Constable {
194 /**
195 * The minimum radix available for conversion to and from strings.
196 * The constant value of this field is the smallest value permitted
197 * for the radix argument in radix-conversion methods such as the
198 * {@code digit} method, the {@code forDigit} method, and the
199 * {@code toString} method of class {@code Integer}.
200 *
201 * @see Character#digit(char, int)
202 * @see Character#forDigit(int, int)
203 * @see Integer#toString(int, int)
204 * @see Integer#valueOf(String)
205 */
206 public static final int MIN_RADIX = 2;
207
208 /**
209 * The maximum radix available for conversion to and from strings.
210 * The constant value of this field is the largest value permitted
211 * for the radix argument in radix-conversion methods such as the
212 * {@code digit} method, the {@code forDigit} method, and the
213 * {@code toString} method of class {@code Integer}.
9006 }
9007
9008 /**
9009 * Returns a {@code Character} instance representing the specified
9010 * {@code char} value.
9011 * If a new {@code Character} instance is not required, this method
9012 * should generally be used in preference to the constructor
9013 * {@link #Character(char)}, as this method is likely to yield
9014 * significantly better space and time performance by caching
9015 * frequently requested values.
9016 *
9017 * This method will always cache values in the range {@code
9018 * '\u005Cu0000'} to {@code '\u005Cu007F'}, inclusive, and may
9019 * cache other values outside of this range.
9020 *
9021 * @param c a char value.
9022 * @return a {@code Character} instance representing {@code c}.
9023 * @since 1.5
9024 */
9025 @IntrinsicCandidate
9026 @DeserializeConstructor
9027 public static Character valueOf(char c) {
9028 if (c <= 127) { // must cache
9029 return CharacterCache.cache[(int)c];
9030 }
9031 return new Character(c);
9032 }
9033
9034 /**
9035 * Returns the value of this {@code Character} object.
9036 * @return the primitive {@code char} value represented by
9037 * this object.
9038 */
9039 @IntrinsicCandidate
9040 public char charValue() {
9041 return value;
9042 }
9043
9044 /**
9045 * Returns a hash code for this {@code Character}; equal to the result
9046 * of invoking {@code charValue()}.
|