/*
    * Copyright 2005-2008 The Kuali Foundation
    * 
    * 
    * Licensed under the Educational Community License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    * http://www.opensource.org/licenses/ecl2.php
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.kuali.rice.kew.transformation;
  
  //Raja Sooriamurthi
  //S531 Web application development
  
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.xpath.XPath;
  import javax.xml.xpath.XPathFactory;
  
  import org.w3c.dom.Document;
  import org.xml.sax.SAXException;
  
  public final class XMLUtil {
  
      
  
  	private XMLUtil() {
  		throw new UnsupportedOperationException("do not call");
  	}
  	
  	// an XPath constructor
  	
  	static XPath makeXPath() {
  		XPathFactory xpfactory = XPathFactory.newInstance();
  		return xpfactory.newXPath();
  	}
  
  	// Three methods for parsing XML documents based on how they are specified
  	//   ... as a file
  	//   ... as a URL
  	//   ... as the contents of an InputStream
  	
  	static Document parseFile(String fname) {
  		InputStream in = null;
  		try {
  			in = new FileInputStream(fname);
  		} catch (FileNotFoundException e) {
  			e.printStackTrace();
  			System.exit(1);
  		}
  		return parseInputStream(in);
  	}
  
  	static Document parseURL(String url) {
  		InputStream in = null;
  		try {
  			in = new URL(url).openStream();
  		} catch (IOException e) {
  			e.printStackTrace();
  			System.exit(1);
  		}
  		return parseInputStream(in);
  	}
  
  	static Document parseInputStream(InputStream in) {
  		Document doc = null;
  		try {
  			DocumentBuilder xml_parser = makeDOMparser();
  			doc = xml_parser.parse(in);
  		} catch (IOException e) {
  			e.printStackTrace();
  			System.exit(1);
  		} catch (SAXException e) {
  			e.printStackTrace();
  			System.exit(1);
  		}
  		return doc;
  	}
  	
  	static DocumentBuilder makeDOMparser() {
  		DocumentBuilder parser = null;
  		try {
  			DocumentBuilderFactory dbfactory = DocumentBuilderFactory.newInstance();
  			dbfactory.setIgnoringElementContentWhitespace(true);
  			parser = dbfactory.newDocumentBuilder();
 		} catch (ParserConfigurationException pce) {
 			pce.printStackTrace();
 			System.exit(1);
 		}
 		return parser;
 	}
     
 }