/*
* @(#)ResponseCtx.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
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package com.sun.xacml.ctx;
import com.sun.xacml.Constants;
import com.sun.xacml.Indenter;
import com.sun.xacml.ParsingException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* Represents the response to a request made to the XACML PDP.
*
* @since 1.0
* @author Seth Proctor
* @author Marco Barreno
*/
public class ResponseCtx
{
// The set of Result objects returned by the PDP
private Set<Result> results = null;
/**
* Constructor that creates a new <code>ResponseCtx</code> with only a
* single <code>Result</code> (a common case).
*
* @param result the single result in the response
*/
public ResponseCtx(Result result) {
this.results = new HashSet<Result>();
this.results.add(result);
}
/**
* Constructor that creates a new <code>ResponseCtx</code> with a
* <code>Set</code> of <code>Result</code>s. The <code>Set</code> must
* be non-empty.
*
* @param results a <code>Set</code> of <code>Result</code> objects
*/
public ResponseCtx(Set<Result> results) {
this.results = Collections.unmodifiableSet(new HashSet<Result>(results));
}
/**
* Creates a new instance of <code>ResponseCtx</code> based on the given
* DOM root node. A <code>ParsingException</code> is thrown if the DOM
* root doesn't represent a valid ResponseType.
*
* @param root the DOM root of a ResponseType
*
* @return a new <code>ResponseCtx</code>
*
* @throws ParsingException if the node is invalid
*/
public static ResponseCtx getInstance(Node root) throws ParsingException {
// check if this really is a response
if (root.getNodeType() != Node.ELEMENT_NODE
|| !root.getLocalName().equals("Response")) {
throw new ParsingException("Can't create a Response from a "
+ root.getLocalName() + " element");
}
Set<Result> results = new HashSet<Result>();
NodeList nodes = root.getChildNodes();
for (int i = 0; i < nodes.getLength(); i++) {
Node node = nodes.item(i);
if (node.getNodeType() == Node.ELEMENT_NODE
&& node.getLocalName().equals("Result")) {
results.add(Result.getInstance(node));
}
}
if (results.size() == 0) {
throw new ParsingException("must have at least one Result");
}
return new ResponseCtx(results);
}
/**
* Creates a new <code>ResponseCtx</code> by parsing XML from an
* input stream. Note that this is a convenience method, and it will
* not do schema validation by default. You should be parsing the data
* yourself, and then providing the root node to the other
* <code>getInstance</code> method. If you use this convenience
* method, you probably want to turn on validation by setting the
* context schema file (see the programmer guide for more information
* on this).
*
* @param input a stream providing the XML data
*
* @return a new <code>ResponseCtx</code>
*
* @throws ParsingException if there is an error parsing the input
*/
public static ResponseCtx getInstance(InputStream input)
throws ParsingException
{
return getInstance(InputParser.parseInput(input, "Response"));
}
/**
* Get the set of <code>Result</code>s from this response.
*
* @return a <code>Set</code> of results
*/
public Set<Result> getResults() {
return this.results;
}
/**
* Encodes this context 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
* @param charsetName the character set to use in encoding of strings.
* This may be null in which case the platform
* default character set will be used.
*
* @throws UnsupportedEncodingException
*/
public void encode(OutputStream output, String charsetName)
throws UnsupportedEncodingException {
encode(output, charsetName, new Indenter(0));
}
/**
* Encodes this context 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 charsetName the character set to use in encoding of strings.
* This may be null in which case the platform
* default character set will be used.
* @param indenter an object that creates indentation strings
*
* @throws UnsupportedEncodingException
*/
public void encode(OutputStream output, String charsetName,
Indenter indenter)
throws UnsupportedEncodingException {
// Make a PrintStream for a nicer printing interface
PrintStream out;
if(charsetName == null) {
out = new PrintStream(output);
} else {
out = new PrintStream(output, false, charsetName);
}
// Prepare the indentation string
String indent = indenter.makeString();
// Now write the XML...
out.println(indent + "<Response xmlns=\"" +
Constants.XACML_3_0_IDENTIFIER + "\">");
// Go through all results
Iterator<Result> it = this.results.iterator();
indenter.in();
while (it.hasNext()) {
Result result = it.next();
result.encode(out, charsetName, indenter);
}
indenter.out();
// Finish the XML for a response
out.println(indent + "</Response>");
}
}