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  * 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

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  *

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 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.getPrimitiveClass("boolean");

     /**

      * 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 {@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(AbstractStringBuilder.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"));

     }

 }