transformingbetweendomandxml.java

介绍xml加密和xml数字签名的方法的源代码

package XMLEncrypt;

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

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
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 org.w3c.dom.Document;
import org.xml.sax.SAXException;

public class TransformingBetweenDOMandXML {
	/*将xml对象转化为DOM对象*/
	public Document XMLtoDOM(String filename) {
		Document doc = null;
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		File f = new File(filename);
		DocumentBuilder builder = null;
		try {
			builder = factory.newDocumentBuilder();
		} catch (ParserConfigurationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		try {
			doc = builder.parse(f);
			//System.out.println("get DOM from XML file OK!");
		} catch (SAXException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return doc;
	}
	
	/*将DOM对象转换为XML对象*/
	public void DOMtoXML(Document doc,String filename){
		//获得将DOM文档转化为XML文件的转换器，在jdk1.4中，有类TransformerFactory
		// 来实现，类Transformer实现转化API。      
		TransformerFactory tfactory = TransformerFactory.newInstance();      
		Transformer transformer;
		try {
			transformer = tfactory.newTransformer();
			//将DOM对象转化为DOMSource类对象，该对象表现为转化成别的表达形式的信息容器。      
			DOMSource source = new DOMSource(doc);
			/* 获得一个StreamResult类对象，该对象是DOM文档转化成的其他形式的文档的容器，可以是XML文件，文本文件，HTML文件。这里为一个XML文件。*/    
			StreamResult result = new StreamResult(new File(filename));
			// 调用API，将DOM文档转化成XML文件。    
			try {
				transformer.transform(source,result);
			} catch (TransformerException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
		} catch (TransformerConfigurationException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
	}
}