| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.lang; |
| |
| /** |
| * The Boolean class wraps a value of the primitive type |
| * {@code boolean} in an object. An object of type |
| * {@code Boolean} contains a single field whose type is |
| * {@code boolean}. |
| * <p> |
| * In addition, this class provides many methods for |
| * converting a {@code boolean} to a {@code String} and a |
| * {@code String} to a {@code boolean}, as well as other |
| * constants and methods useful when dealing with a |
| * {@code boolean}. |
| * |
| * @author Arthur van Hoff |
| * @since JDK1.0 |
| */ |
| public final class Boolean implements java.io.Serializable, |
| Comparable<Boolean> |
| { |
| /** |
| * The {@code Boolean} object corresponding to the primitive |
| * value {@code true}. |
| */ |
| public static final Boolean TRUE = new Boolean(true); |
| |
| /** |
| * The {@code Boolean} object corresponding to the primitive |
| * value {@code false}. |
| */ |
| public static final Boolean FALSE = new Boolean(false); |
| |
| /** |
| * The Class object representing the primitive type boolean. |
| * |
| * @since JDK1.1 |
| */ |
| public static final Class<Boolean> TYPE = (Class<Boolean>) boolean[].class.getComponentType(); |
| |
| /** |
| * The value of the Boolean. |
| * |
| * @serial |
| */ |
| private final boolean value; |
| |
| /** use serialVersionUID from JDK 1.0.2 for interoperability */ |
| private static final long serialVersionUID = -3665804199014368530L; |
| |
| /** |
| * Allocates a {@code Boolean} object representing the |
| * {@code value} argument. |
| * |
| * <p><b>Note: It is rarely appropriate to use this constructor. |
| * Unless a <i>new</i> instance is required, the static factory |
| * {@link #valueOf(boolean)} is generally a better choice. It is |
| * likely to yield significantly better space and time performance.</b> |
| * |
| * @param value the value of the {@code Boolean}. |
| */ |
| public Boolean(boolean value) { |
| this.value = value; |
| } |
| |
| /** |
| * Allocates a {@code Boolean} object representing the value |
| * {@code true} if the string argument is not {@code null} |
| * and is equal, ignoring case, to the string {@code "true"}. |
| * Otherwise, allocate a {@code Boolean} object representing the |
| * value {@code false}. Examples:<p> |
| * {@code new Boolean("True")} produces a {@code Boolean} object |
| * that represents {@code true}.<br> |
| * {@code new Boolean("yes")} produces a {@code Boolean} object |
| * that represents {@code false}. |
| * |
| * @param s the string to be converted to a {@code Boolean}. |
| */ |
| public Boolean(String s) { |
| this(toBoolean(s)); |
| } |
| |
| /** |
| * Parses the string argument as a boolean. The {@code boolean} |
| * returned represents the value {@code true} if the string argument |
| * is not {@code null} and is equal, ignoring case, to the string |
| * {@code "true"}. <p> |
| * Example: {@code Boolean.parseBoolean("True")} returns {@code true}.<br> |
| * Example: {@code Boolean.parseBoolean("yes")} returns {@code false}. |
| * |
| * @param s the {@code String} containing the boolean |
| * representation to be parsed |
| * @return the boolean represented by the string argument |
| * @since 1.5 |
| */ |
| public static boolean parseBoolean(String s) { |
| return toBoolean(s); |
| } |
| |
| /** |
| * Returns the value of this {@code Boolean} object as a boolean |
| * primitive. |
| * |
| * @return the primitive {@code boolean} value of this object. |
| */ |
| public boolean booleanValue() { |
| return value; |
| } |
| |
| /** |
| * Returns a {@code Boolean} instance representing the specified |
| * {@code boolean} value. If the specified {@code boolean} value |
| * is {@code true}, this method returns {@code Boolean.TRUE}; |
| * if it is {@code false}, this method returns {@code Boolean.FALSE}. |
| * If a new {@code Boolean} instance is not required, this method |
| * should generally be used in preference to the constructor |
| * {@link #Boolean(boolean)}, as this method is likely to yield |
| * significantly better space and time performance. |
| * |
| * @param b a boolean value. |
| * @return a {@code Boolean} instance representing {@code b}. |
| * @since 1.4 |
| */ |
| public static Boolean valueOf(boolean b) { |
| return (b ? TRUE : FALSE); |
| } |
| |
| /** |
| * Returns a {@code Boolean} with a value represented by the |
| * specified string. The {@code Boolean} returned represents a |
| * true value if the string argument is not {@code null} |
| * and is equal, ignoring case, to the string {@code "true"}. |
| * |
| * @param s a string. |
| * @return the {@code Boolean} value represented by the string. |
| */ |
| public static Boolean valueOf(String s) { |
| return toBoolean(s) ? TRUE : FALSE; |
| } |
| |
| /** |
| * Returns a {@code String} object representing the specified |
| * boolean. If the specified boolean is {@code true}, then |
| * the string {@code "true"} will be returned, otherwise the |
| * string {@code "false"} will be returned. |
| * |
| * @param b the boolean to be converted |
| * @return the string representation of the specified {@code boolean} |
| * @since 1.4 |
| */ |
| public static String toString(boolean b) { |
| return b ? "true" : "false"; |
| } |
| |
| /** |
| * Returns a {@code String} object representing this Boolean's |
| * value. If this object represents the value {@code true}, |
| * a string equal to {@code "true"} is returned. Otherwise, a |
| * string equal to {@code "false"} is returned. |
| * |
| * @return a string representation of this object. |
| */ |
| public String toString() { |
| return value ? "true" : "false"; |
| } |
| |
| /** |
| * Returns a hash code for this {@code Boolean} object. |
| * |
| * @return the integer {@code 1231} if this object represents |
| * {@code true}; returns the integer {@code 1237} if this |
| * object represents {@code false}. |
| */ |
| public int hashCode() { |
| return value ? 1231 : 1237; |
| } |
| |
| /** |
| * Returns a hash code for a {@code boolean} value; compatible with |
| * {@code Boolean.hashCode()}. |
| * |
| * @param value the value to hash |
| * @return a hash code value for a {@code boolean} value. |
| * @since 1.8 |
| */ |
| public static int hashCode(boolean value) { |
| return value ? 1231 : 1237; |
| } |
| |
| /** |
| * Returns {@code true} if and only if the argument is not |
| * {@code null} and is a {@code Boolean} object that |
| * represents the same {@code boolean} value as this object. |
| * |
| * @param obj the object to compare with. |
| * @return {@code true} if the Boolean objects represent the |
| * same value; {@code false} otherwise. |
| */ |
| public boolean equals(Object obj) { |
| if (obj instanceof Boolean) { |
| return value == ((Boolean)obj).booleanValue(); |
| } |
| return false; |
| } |
| |
| /** |
| * Returns {@code true} if and only if the system property |
| * named by the argument exists and is equal to the string |
| * {@code "true"}. (Beginning with version 1.0.2 of the |
| * Java<small><sup>TM</sup></small> platform, the test of |
| * this string is case insensitive.) A system property is accessible |
| * through {@code getProperty}, a method defined by the |
| * {@code System} class. |
| * <p> |
| * If there is no property with the specified name, or if the specified |
| * name is empty or null, then {@code false} is returned. |
| * |
| * @param name the system property name. |
| * @return the {@code boolean} value of the system property. |
| * @see java.lang.System#getProperty(java.lang.String) |
| * @see java.lang.System#getProperty(java.lang.String, java.lang.String) |
| */ |
| public static boolean getBoolean(String name) { |
| boolean result = false; |
| try { |
| result = toBoolean(System.getProperty(name)); |
| } catch (IllegalArgumentException e) { |
| } catch (NullPointerException e) { |
| } |
| return result; |
| } |
| |
| /** |
| * Compares this {@code Boolean} instance with another. |
| * |
| * @param b the {@code Boolean} instance to be compared |
| * @return zero if this object represents the same boolean value as the |
| * argument; a positive value if this object represents true |
| * and the argument represents false; and a negative value if |
| * this object represents false and the argument represents true |
| * @throws NullPointerException if the argument is {@code null} |
| * @see Comparable |
| * @since 1.5 |
| */ |
| public int compareTo(Boolean b) { |
| return compare(this.value, b.value); |
| } |
| |
| /** |
| * Compares two {@code boolean} values. |
| * The value returned is identical to what would be returned by: |
| * <pre> |
| * Boolean.valueOf(x).compareTo(Boolean.valueOf(y)) |
| * </pre> |
| * |
| * @param x the first {@code boolean} to compare |
| * @param y the second {@code boolean} to compare |
| * @return the value {@code 0} if {@code x == y}; |
| * a value less than {@code 0} if {@code !x && y}; and |
| * a value greater than {@code 0} if {@code x && !y} |
| * @since 1.7 |
| */ |
| public static int compare(boolean x, boolean y) { |
| return (x == y) ? 0 : (x ? 1 : -1); |
| } |
| |
| private static boolean toBoolean(String name) { |
| return ((name != null) && name.equalsIgnoreCase("true")); |
| } |
| } |
