/*
* @(#)VariableDefinition.java
*
* Copyright 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
* 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
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package org.jboss.security.xacml.sunxacml.cond;
import java.io.OutputStream;
import java.io.PrintStream;
import org.jboss.security.xacml.sunxacml.Indenter;
import org.jboss.security.xacml.sunxacml.ParsingException;
import org.jboss.security.xacml.sunxacml.PolicyMetaData;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* This class supports the VariableDefinitionType type introuced in XACML
* 2.0. It allows a Policy to pre-define any number of expression blocks for
* general use. Note that it's legal (though not usually useful) to define
* expressions that don't get referenced within the Policy. It is illegal to
* have more than one definition with the same identifier within a Policy.
*
* @since 2.0
* @author Seth Proctor
*/
public class VariableDefinition
{
// the identitifer for this definition
private String variableId;
// the actual expression defined here
private Expression expression;
/**
* Creates a new <code>VariableDefinition</code> with the given
* identifier and expression.
*
* @param variableId the identifier for this definition
* @param expression the expression defined here
*/
public VariableDefinition(String variableId, Expression expression) {
this.variableId = variableId;
this.expression = expression;
}
/**
* Returns a new instance of the <code>VariableDefinition</code> class
* based on a DOM node. The node must be the root of an XML
* VariableDefinitionType.
*
* @param root the DOM root of a VariableDefinitionType XML type
* @param metaData the meta-data associated with the containing policy
* @param manager <code>VariableManager</code> used to connect references
* to this definition
*
* @throws ParsingException if the VariableDefinitionType is invalid
*/
public static VariableDefinition getInstance(Node root,
PolicyMetaData metaData,
VariableManager manager)
throws ParsingException
{
String variableId = root.getAttributes().getNamedItem("VariableId").
getNodeValue();
// get the first element, which is the expression node
NodeList nodes = root.getChildNodes();
Node xprNode = nodes.item(0);
int i = 1;
while (xprNode.getNodeType() != Node.ELEMENT_NODE)
xprNode = nodes.item(i++);
// use that node to get the expression
Expression xpr = ExpressionHandler.
parseExpression(xprNode, metaData, manager);
return new VariableDefinition(variableId, xpr);
}
/**
* Returns the identifier for this definition.
*
* @return the definition's identifier
*/
public String getVariableId() {
return variableId;
}
/**
* Returns the expression provided by this definition.
*
* @return the definition's expression
*/
public Expression getExpression() {
return expression;
}
/**
* Encodes this class into its XML representation and writes this
* encoding to the given <code>OutputStream</code> with no indentation.
*
* @param output a stream into which the XML-encoded data is written
*/
public void encode(OutputStream output) {
encode(output, new Indenter(0));
}
/**
* Encodes this class into its XML representation and writes this
* encoding to the given <code>OutputStream</code> with indentation.
*
* @param output a stream into which the XML-encoded data is written
* @param indenter an object that creates indentation strings
*/
public void encode(OutputStream output, Indenter indenter) {
PrintStream out = new PrintStream(output);
String indent = indenter.makeString();
out.println(indent + "<VariableDefinition VariableId=\"" +
variableId + "\">");
indenter.in();
expression.encode(output, indenter);
out.println("</VariableDefinition>");
indenter.out();
}
}