/*
* @(#)InputParser.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.ParsingException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import org.apache.log4j.Logger;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
/**
* A package-private helper that provides a single static routine for
* parsing input based on the context schema.
*
* @since 1.0
* @author Seth Proctor
*/
class InputParser implements ErrorHandler
{
// the schema file, if provided
private File schemaFile;
// the single reference, which is null unless a schema file is provided
private static InputParser ipReference = null;
// the property string to set to turn on validation
private static final String CONTEXT_SCHEMA_PROPERTY =
"com.sun.xacml.ContextSchema";
// the logger we'll use for all messages
private static final Logger logger =
Logger.getLogger(InputParser.class.getName());
// standard strings for setting validation
private static final String JAXP_SCHEMA_LANGUAGE =
"http://java.sun.com/xml/jaxp/properties/schemaLanguage";
private static final String W3C_XML_SCHEMA =
"http://www.w3.org/2001/XMLSchema";
private static final String JAXP_SCHEMA_SOURCE =
"http://java.sun.com/xml/jaxp/properties/schemaSource";
/**
* Look for the property that names the schema, and if it exists get
* the file name and create a single InputParser instance
*/
static {
String schemaName = System.getProperty(CONTEXT_SCHEMA_PROPERTY);
if (schemaName != null) {
ipReference = new InputParser(new File(schemaName));
}
}
/**
* Constructor that takes the schema file.
*/
private InputParser(File schemaFile) {
this.schemaFile = schemaFile;
}
/**
* Tries to Parse the given output as a Context document.
*
* @param input the stream to parse
* @param rootTag either "Request" or "Response"
*
* @return the root node of the request/response
*
* @throws ParsingException if a problem occurred parsing the document
*/
static Node parseInput(InputStream input, String rootTag)
throws ParsingException
{
NodeList nodes = null;
try {
DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
factory.setIgnoringComments(true);
DocumentBuilder builder = null;
// as of 1.2, we always are namespace aware
factory.setNamespaceAware(true);
if (ipReference == null) {
// we're not validating
factory.setValidating(false);
builder = factory.newDocumentBuilder();
} else {
// we are validating
factory.setValidating(true);
factory.setAttribute(JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA);
factory.setAttribute(JAXP_SCHEMA_SOURCE,
ipReference.schemaFile);
builder = factory.newDocumentBuilder();
builder.setErrorHandler(ipReference);
}
Document doc = builder.parse(input);
nodes = doc.getElementsByTagName(rootTag);
} catch (ParserConfigurationException e) {
throw new ParsingException("Error tring to parse " + rootTag +
"Type", e);
} catch (SAXException e) {
throw new ParsingException("Error tring to parse " + rootTag +
"Type", e);
} catch (IOException e) {
throw new ParsingException("Error tring to parse " + rootTag +
"Type", e);
}
if (nodes.getLength() != 1) {
throw new ParsingException("Only one " + rootTag + "Type allowed "
+ "at the root of a Context doc");
}
return nodes.item(0);
}
/**
* Standard handler routine for the XML parsing.
*
* @param exception information on what caused the problem
*/
public void warning(SAXParseException exception) {
logger.warn("Warning on line " + exception.getLineNumber() +
": " + exception.getMessage());
}
/**
* Standard handler routine for the XML parsing.
*
* @param exception information on what caused the problem
*
* @throws SAXException always to halt parsing on errors
*/
public void error(SAXParseException exception) throws SAXException {
logger.warn("Error on line " + exception.getLineNumber() +
": " + exception.getMessage());
throw new SAXException("invalid context document");
}
/**
* Standard handler routine for the XML parsing.
*
* @param exception information on what caused the problem
*
* @throws SAXException always to halt parsing on errors
*/
public void fatalError(SAXParseException exception) throws SAXException {
logger.warn("FatalError on line " + exception.getLineNumber() +
": " + exception.getMessage());
throw new SAXException("invalid context document");
}
}