/*
* @(#)BooleanAttribute.java
*
* Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
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*
* You acknowledge that this software is not designed or intended for use in
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*/
package com.sun.xacml.attr;
import java.net.URI;
import org.w3c.dom.Node;
import com.sun.xacml.ParsingException;
/**
* Representation of an xs:boolean value. This class supports parsing xs:boolean values. All objects
* of this class are immutable and all methods of the class are thread-safe.
*
* @since 1.0
* @author Marco Barreno
* @author Steve Hanna
*/
public class BooleanAttribute extends AttributeValue {
/**
* Official name of this type
*/
public static final String identifier = "http://www.w3.org/2001/XMLSchema#boolean";
/**
* URI version of name for this type
*/
private static final URI identifierURI = URI.create(identifier);
/**
* Single instance of BooleanAttribute that represents true. Initialized by the static
* initializer below.
*/
private static BooleanAttribute trueInstance = new BooleanAttribute(true);
/**
* Single instance of BooleanAttribute that represents false. Initialized by the static
* initializer below.
*/
private static BooleanAttribute falseInstance = new BooleanAttribute(false);
/**
* The actual boolean value that this object represents.
*/
private boolean value;
/**
* Creates a new <code>BooleanAttribute</code> that represents the boolean value supplied.
* <p>
* This constructor is private because it should not be used by anyone other than the static
* initializer in this class. Instead, please use one of the getInstance methods, which will
* ensure that only two BooleanAttribute objects are created, thus avoiding excess object
* creation.
*/
private BooleanAttribute(boolean value) {
super(identifierURI);
this.value = value;
}
/**
* Returns a <code>BooleanAttribute</code> that represents the xs:boolean at a particular DOM
* node.
*
* @param root
* the <code>Node</code> that contains the desired value
* @return a <code>BooleanAttribute</code> representing the appropriate value (null if there is
* a parsing error)
*/
public static BooleanAttribute getInstance(Node root) throws ParsingException {
return getInstance(root.getFirstChild().getNodeValue());
}
/**
* Returns a <code>BooleanAttribute</code> that represents the xs:boolean value indicated by the
* string provided.
*
* @param value
* a string representing the desired value
* @return a <code>BooleanAttribute</code> representing the appropriate value (null if there is
* a parsing error)
*/
public static BooleanAttribute getInstance(String value) throws ParsingException {
if (value.equals("true"))
return trueInstance;
if (value.equals("false"))
return falseInstance;
throw new ParsingException("Boolean string must be true or false");
}
/**
* Returns a <code>BooleanAttribute</code> that represents the boolean value provided.
*
* @param value
* a boolean representing the desired value
* @return a <code>BooleanAttribute</code> representing the appropriate value
*/
public static BooleanAttribute getInstance(boolean value) {
if (value)
return trueInstance;
else
return falseInstance;
}
/**
* Returns a <code>BooleanAttribute</code> that represents a true value.
*
* @return a <code>BooleanAttribute</code> representing a true value
*/
public static BooleanAttribute getTrueInstance() {
return trueInstance;
}
/**
* Returns a <code>BooleanAttribute</code> that represents a false value.
*
* @return a <code>BooleanAttribute</code> representing a false value
*/
public static BooleanAttribute getFalseInstance() {
return falseInstance;
}
/**
* Returns the <code>boolean</code> value represented by this object.
*
* @return the <code>boolean</code> value
*/
public boolean getValue() {
return value;
}
/**
* Returns true if the input is an instance of this class and if its value equals the value
* contained in this class.
*
* @param o
* the object to compare
*
* @return true if this object and the input represent the same value
*/
public boolean equals(Object o) {
if (!(o instanceof BooleanAttribute))
return false;
BooleanAttribute other = (BooleanAttribute) o;
return (value == other.value);
}
/**
* Returns the hashcode value used to index and compare this object with others of the same
* type. Typically this is the hashcode of the backing data object.
*
* @return the object's hashcode value
*/
public int hashCode() {
// these numbers come from the javadoc for java.lang.Boolean...no,
// really, they do. I can't imagine what they were thinking...
return (value ? 1231 : 1237);
}
/**
*
*/
public String encode() {
return (value ? "true" : "false");
}
}