/*
* @(#)StringAttribute.java
*
* Copyright 2003-2005 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
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*/
package com.sun.xacml.attr;
import java.net.URI;
import org.w3c.dom.Node;
/**
* Representation of an xs:string value. This class supports parsing xs:string values. All objects
* of this class are immutable and all methods of the class are thread-safe.
* <p>
* Note that there was some confusion in the XACML specification about whether this datatype should
* be able to handle XML elements (ie, whether <AttributeValue
* DataType="...string"><foo/> </AttributeValue> is valid). This has been clarified
* to provide the correct requirement that a string may not contain mixed content (ie, the example
* provided here is invalid). If you need to specify something like this with the string datatype,
* then you must escape the <code><</code> and <code>></code> characters.
*
* @since 1.0
* @author Marco Barreno
* @author Seth Proctor
* @author Steve Hanna
*/
public class StringAttribute extends AttributeValue {
/**
* Official name of this type
*/
public static final String identifier = "http://www.w3.org/2001/XMLSchema#string";
/**
* URI version of name for this type
*/
private static final URI identifierURI = URI.create(identifier);
/**
* The actual String value that this object represents.
*/
private String value;
/**
* Creates a new <code>StringAttribute</code> that represents the String value supplied.
*
* @param value
* the <code>String</code> value to be represented
*/
public StringAttribute(String value) {
super(identifierURI);
// TODO: document why a null pointer is allowed here and not for other
// attributes.
if (value == null)
this.value = "";
else
this.value = value;
}
/**
* Returns a new <code>StringAttribute</code> that represents the xs:string at a particular DOM
* node.
*
* @param root
* the <code>Node</code> that contains the desired value
* @return a new <code>StringAttribute</code> representing the appropriate value (null if there
* is a parsing error)
*/
public static StringAttribute getInstance(Node root) {
Node node = root.getFirstChild();
// Strings are allowed to have an empty AttributeValue element and are
// just treated as empty strings...we have to handle this case
if (node == null)
return new StringAttribute("");
// get the type of the node
short type = node.getNodeType();
// now see if we have (effectively) a simple string value
if ((type == Node.TEXT_NODE) || (type == Node.CDATA_SECTION_NODE)
|| (type == Node.COMMENT_NODE)) {
return getInstance(node.getNodeValue());
}
// there is some confusion in the specifications about what should
// happen at this point, but the strict reading of the XMLSchema
// specification suggests that this should be an error
return null;
}
/**
* Returns a new <code>StringAttribute</code> that represents the xs:string value indicated by
* the <code>String</code> provided.
*
* @param value
* a string representing the desired value
* @return a new <code>StringAttribute</code> representing the appropriate value
*/
public static StringAttribute getInstance(String value) {
return new StringAttribute(value);
}
/**
* Returns the <code>String</code> value represented by this object.
*
* @return the <code>String</code> value
*/
public String 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 StringAttribute))
return false;
StringAttribute other = (StringAttribute) o;
return value.equals(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() {
return value.hashCode();
}
/**
* Converts to a String representation.
*
* @return the String representation
*/
public String toString() {
return "StringAttribute: \"" + value + "\"";
}
/**
*
*/
public String encode() {
return value;
}
}