求Boolean类源代码

/*
* %W% %E%
*
* Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/package java.lang;/**
* The Boolean class wraps a value of the primitive type
* <code>boolean</code> in an object. An object of type
* <code>Boolean</code> contains a single field whose type is
* <code>boolean</code>.
* 
* In addition, this class provides many methods for
* converting a <code>boolean</code> to a <code>String</code> and a
* <code>String</code> to a <code>boolean</code>, as well as other
* constants and methods useful when dealing with a
* <code>boolean</code>.
*
* @author Arthur van Hoff
* @version %I%, %G%
* @since JDK1.0
*/
public final class Boolean implements java.io.Serializable,
 Comparable<Boolean>
{
 /**
 * The <code>Boolean</code> object corresponding to the primitive
 * value <code>true</code>.
 */
 public static final Boolean TRUE = new Boolean(true); /**
 * The <code>Boolean</code> object corresponding to the primitive
 * value <code>false</code>.
 */
 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</code> object representing the
 * <code>value</code> argument.
 *
 * Note: It is rarely appropriate to use this constructor.
 * Unless a new 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.
 *
 * @param value the value of the <code>Boolean</code>.
 */
 public Boolean(boolean value) {
this.value = value;
 } /**
 * Allocates a <code>Boolean</code> object representing the value
 * <code>true</code> if the string argument is not <code>null</code>
 * and is equal, ignoring case, to the string {@code "true"}.
 * Otherwise, allocate a <code>Boolean</code> object representing the
 * value <code>false</code>. Examples:
 * {@code new Boolean("True")} produces a <tt>Boolean</tt> object
 * that represents <tt>true</tt>. 
 * {@code new Boolean("yes")} produces a <tt>Boolean</tt> object
 * that represents <tt>false</tt>.
 *
 * @param s the string to be converted to a <code>Boolean</code>.
 */
 public Boolean(String s) {
this(toBoolean(s));
 } /**
 * Parses the string argument as a boolean. The <code>boolean</code>
 * returned represents the value <code>true</code> if the string argument
 * is not <code>null</code> and is equal, ignoring case, to the string
 * {@code "true"}. 
 * Example: {@code Boolean.parseBoolean("True")} returns <tt>true</tt>. 
 * Example: {@code Boolean.parseBoolean("yes")} returns <tt>false</tt>.
 *
 * @param s the <code>String</code> 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 <tt>Boolean</tt> object as a boolean
 * primitive.
 *
 * @return the primitive <code>boolean</code> value of this object.
 */
 public boolean booleanValue() {
return value;
 } /**
 * Returns a <tt>Boolean</tt> instance representing the specified
 * <tt>boolean</tt> value. If the specified <tt>boolean</tt> value
 * is <tt>true</tt>, this method returns <tt>Boolean.TRUE</tt>;
 * if it is <tt>false</tt>, this method returns <tt>Boolean.FALSE</tt>.
 * If a new <tt>Boolean</tt> 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 <tt>Boolean</tt> instance representing <tt>b</tt>.
 * @since 1.4
 */
 public static Boolean valueOf(boolean b) {
 return (b ? TRUE : FALSE);
 } /**
 * Returns a <code>Boolean</code> with a value represented by the
 * specified string. The <code>Boolean</code> returned represents a
 * true value if the string argument is not <code>null</code>
 * and is equal, ignoring case, to the string {@code "true"}.
 *
 * @param s a string.
 * @return the <code>Boolean</code> value represented by the string.
 */
 public static Boolean valueOf(String s) {
return toBoolean(s) ? TRUE : FALSE;
 } /**
 * Returns a <tt>String</tt> object representing the specified
 * boolean. If the specified boolean is <code>true</code>, 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</code>
 * @since 1.4
 */
 public static String toString(boolean b) {
 return b ? "true" : "false";
 } /**
 * Returns a <tt>String</tt> object representing this Boolean's
 * value. If this object represents the value <code>true</code>,
 * 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 <tt>Boolean</tt> object.
 *
 * @return the integer <tt>1231</tt> if this object represents
 * <tt>true</tt>; returns the integer <tt>1237</tt> if this
 * object represents <tt>false</tt>.
 */
 public int hashCode() {
return value ? 1231 : 1237;
 } /**
 * Returns <code>true</code> if and only if the argument is not
 * <code>null</code> and is a <code>Boolean</code> object that
 * represents the same <code>boolean</code> value as this object.
 *
 * @param obj the object to compare with.
 * @return <code>true</code> if the Boolean objects represent the
 * same value; <code>false</code> otherwise.
 */
 public boolean equals(Object obj) {
if (obj instanceof Boolean) {
 return value == ((Boolean)obj).booleanValue();
}
return false;
 } /**
 * Returns <code>true</code> 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
 * JavaTM platform, the test of
 * this string is case insensitive.) A system property is accessible
 * through <code>getProperty</code>, a method defined by the
 * <code>System</code> class.
 * 
 * If there is no property with the specified name, or if the specified
 * name is empty or null, then <code>false</code> is returned.
 *
 * @param name the system property name.
 * @return the <code>boolean</code> 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 <tt>Boolean</tt> instance with another.
 *
 * @param b the <tt>Boolean</tt> 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 <tt>null</tt>
 * @see Comparable
 * @since 1.5
 */
 public int compareTo(Boolean b) {
 return (b.value == value ? 0 : (value ? 1 : -1));
 } private static boolean toBoolean(String name) {
return ((name != null) && name.equalsIgnoreCase("true"));
 }
}

JDK安装目录下面有个src.zip，自己解压了去看。

Boolean 源码就在JDK 目录下的src.zip包里,导到eclipse中,可以直接查看的.

/*
* %W% %E%
*
* Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/package java.lang;/**
* The Boolean class wraps a value of the primitive type
* <code>boolean</code> in an object. An object of type
* <code>Boolean</code> contains a single field whose type is
* <code>boolean</code>.
* 
* In addition, this class provides many methods for
* converting a <code>boolean</code> to a <code>String</code> and a
* <code>String</code> to a <code>boolean</code>, as well as other
* constants and methods useful when dealing with a
* <code>boolean</code>.
*
* @author Arthur van Hoff
* @version %I%, %G%
* @since JDK1.0
*/
public final class Boolean implements java.io.Serializable,
 Comparable<Boolean>
{
 /**
 * The <code>Boolean</code> object corresponding to the primitive
 * value <code>true</code>.
 */
 public static final Boolean TRUE = new Boolean(true); /**
 * The <code>Boolean</code> object corresponding to the primitive
 * value <code>false</code>.
 */
 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</code> object representing the
 * <code>value</code> argument.
 *
 * Note: It is rarely appropriate to use this constructor.
 * Unless a new 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.
 *
 * @param value the value of the <code>Boolean</code>.
 */
 public Boolean(boolean value) {
this.value = value;
 } /**
 * Allocates a <code>Boolean</code> object representing the value
 * <code>true</code> if the string argument is not <code>null</code>
 * and is equal, ignoring case, to the string {@code "true"}.
 * Otherwise, allocate a <code>Boolean</code> object representing the
 * value <code>false</code>. Examples:
 * {@code new Boolean("True")} produces a <tt>Boolean</tt> object
 * that represents <tt>true</tt>. 
 * {@code new Boolean("yes")} produces a <tt>Boolean</tt> object
 * that represents <tt>false</tt>.
 *
 * @param s the string to be converted to a <code>Boolean</code>.
 */
 public Boolean(String s) {
this(toBoolean(s));
 } /**
 * Parses the string argument as a boolean. The <code>boolean</code>
 * returned represents the value <code>true</code> if the string argument
 * is not <code>null</code> and is equal, ignoring case, to the string
 * {@code "true"}. 
 * Example: {@code Boolean.parseBoolean("True")} returns <tt>true</tt>. 
 * Example: {@code Boolean.parseBoolean("yes")} returns <tt>false</tt>.
 *
 * @param s the <code>String</code> 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 <tt>Boolean</tt> object as a boolean
 * primitive.
 *
 * @return the primitive <code>boolean</code> value of this object.
 */
 public boolean booleanValue() {
return value;
 } /**
 * Returns a <tt>Boolean</tt> instance representing the specified
 * <tt>boolean</tt> value. If the specified <tt>boolean</tt> value
 * is <tt>true</tt>, this method returns <tt>Boolean.TRUE</tt>;
 * if it is <tt>false</tt>, this method returns <tt>Boolean.FALSE</tt>.
 * If a new <tt>Boolean</tt> 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 <tt>Boolean</tt> instance representing <tt>b</tt>.
 * @since 1.4
 */
 public static Boolean valueOf(boolean b) {
 return (b ? TRUE : FALSE);
 } /**
 * Returns a <code>Boolean</code> with a value represented by the
 * specified string. The <code>Boolean</code> returned represents a
 * true value if the string argument is not <code>null</code>
 * and is equal, ignoring case, to the string {@code "true"}.
 *
 * @param s a string.
 * @return the <code>Boolean</code> value represented by the string.
 */
 public static Boolean valueOf(String s) {
return toBoolean(s) ? TRUE : FALSE;
 } /**
 * Returns a <tt>String</tt> object representing the specified
 * boolean. If the specified boolean is <code>true</code>, 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</code>
 * @since 1.4
 */
 public static String toString(boolean b) {
 return b ? "true" : "false";
 } /**
 * Returns a <tt>String</tt> object representing this Boolean's
 * value. If this object represents the value <code>true</code>,
 * 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 <tt>Boolean</tt> object.
 *
 * @return the integer <tt>1231</tt> if this object represents
 * <tt>true</tt>; returns the integer <tt>1237</tt> if this
 * object represents <tt>false</tt>.
 */
 public int hashCode() {
return value ? 1231 : 1237;
 } /**
 * Returns <code>true</code> if and only if the argument is not
 * <code>null</code> and is a <code>Boolean</code> object that
 * represents the same <code>boolean</code> value as this object.
 *
 * @param obj the object to compare with.
 * @return <code>true</code> if the Boolean objects represent the
 * same value; <code>false</code> otherwise.
 */
 public boolean equals(Object obj) {
if (obj instanceof Boolean) {
 return value == ((Boolean)obj).booleanValue();
}
return false;
 } /**
 * Returns <code>true</code> 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
 * JavaTM platform, the test of
 * this string is case insensitive.) A system property is accessible
 * through <code>getProperty</code>, a method defined by the
 * <code>System</code> class.
 * 
 * If there is no property with the specified name, or if the specified
 * name is empty or null, then <code>false</code> is returned.
 *
 * @param name the system property name.
 * @return the <code>boolean</code> 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 <tt>Boolean</tt> instance with another.
 *
 * @param b the <tt>Boolean</tt> 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 <tt>null</tt>
 * @see Comparable
 * @since 1.5
 */
 public int compareTo(Boolean b) {
 return (b.value == value ? 0 : (value ? 1 : -1));
 } private static boolean toBoolean(String name) {
return ((name != null) && name.equalsIgnoreCase("true"));
 }
}

ticmy，授人以鱼不如授人以渔你下载的jdk文件夹下，有一个src.zip

调试易

求Boolean类源代码

解决方案 »