XMLHelper.java

/*
* Copyright (c) 2010-2012 Research In Motion Limited. All rights reserved.
*
* This program and the accompanying materials are made available
* under  the terms of the Apache License, Version 2.0,
* which accompanies this distribution and is available at
*
* http://www.apache.org/licenses/LICENSE-2.0
* 
*/
package net.rim.ejde.installer;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class XMLHelper {
    public static void writeXmlFile(Document doc, String filename) {
        try {
            // Prepare the DOM document for writing
            Source source = new DOMSource(doc);
    
            // Prepare the output file
            File file = new File(filename);
            Result result = new StreamResult(file);
    
            // Write the DOM document to the file
            Transformer xformer = TransformerFactory.newInstance().newTransformer();
            xformer.transform(source, result);
        } catch (TransformerConfigurationException ex) {
            System.out.println(ex.getMessage());
        } catch (TransformerException ex) {
            System.out.println(ex.getMessage());
        }
    }

    public static Document openXmlFile(String filename, boolean validating) {
    	return openXmlFile(new File(filename), validating);
    }
    
    public static Document openXmlFile(File file, boolean validating) {
        try {
            // Create a builder factory
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            factory.setValidating(validating);

            // Create the builder and parse the file
            Document doc = factory.newDocumentBuilder().parse(file);
            return doc;
        } catch (SAXException e) {
            // A parsing error occurred; the xml input is not valid
        } catch (ParserConfigurationException ex) {
            System.out.println(ex.getMessage());
        } catch (IOException ex) {
            System.out.println(ex.getMessage());
        }
        
        return null;
    }
    
    public static String evaluate(File xmlFile, String xPathExpression) {
    	String result=null;
    	
    	try {
    		XPathFactory factory=XPathFactory.newInstance();
    		XPath xPath=factory.newXPath();
    		result=xPath.evaluate(xPathExpression, new InputSource(new FileInputStream(xmlFile)));
    	}catch (Exception ex) {
    		System.out.println(ex.getMessage());
    	}
    	
    	return result;
    }

}