xml文档操作

/**
*
*/
package com.gootrip.util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

/**
* @author advance
*
*/
public class Dom4jHelper {
/**
* 解析url xml文档
* @param url
* @return
* @throws DocumentException
*/
public Document parse(URL url) throws DocumentException {
SAXReader reader = new SAXReader();
Document document = reader.read(url);
return document;
}
/**
* 遍历解析文档
* @param document
*/
public void treeWalk(Document document) {
treeWalk( document.getRootElement() );
}
/**
* 遍历解析元素
* @param element
*/
public void treeWalk(Element element) {
for ( int i = 0, size = element.nodeCount(); i < size; i++ ) {
Node node = element.node(i);
if ( node instanceof Element ) {
treeWalk( (Element) node );
}
else {
// 处理....
}
}
}

/**
* 解析文件，获得根元素
* @param xmlPath
* @param encoding
* @return
* @throws Exception
*/
public static Element parse(String xmlPath,String encoding)throws Exception{
//文件是否存在
File file = new File(xmlPath);
if(!file.exists()){
throw new Exception("找不到xml文件："+xmlPath);
}

//解析
SAXReader reader = new SAXReader(false);
Document doc = reader.read(new FileInputStream(file),encoding);
Element root = doc.getRootElement();
return root;
}

/**
* 保存文档
* @param doc
* @param xmlPath
* @param encoding
* @throws Exception
*/
public static void save(Document doc,String xmlPath,String encoding)throws Exception{
OutputFormat format=OutputFormat.createPrettyPrint();
format.setEncoding(encoding);
XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream(xmlPath),encoding),format);
writer.write(doc);
writer.flush();
writer.close();
}
/**
* 修改xml某节点的值
* @param inputXml 原xml文件
* @param nodes 要修改的节点
* @param attributename 属性名称
* @param value 新值
* @param outXml 输出文件路径及文件名 如果输出文件为null，则默认为原xml文件
*/
public static void modifyDocument(File inputXml, String nodes, String attributename, String value, String outXml) {
try {
SAXReader saxReader = new SAXReader();
Document document = saxReader.read(inputXml);
List list = document.selectNodes(nodes);
Iterator iter = list.iterator();
while (iter.hasNext()) {
Attribute attribute = (Attribute) iter.next();
if (attribute.getName().equals(attributename))
attribute.setValue(value);
}
XMLWriter output;
if (outXml != null){ //指定输出文件
output = new XMLWriter(new FileWriter(new File(outXml)));
}else{ //输出文件为原文件
output = new XMLWriter(new FileWriter(inputXml));
}
output.write(document);
output.close();
}

catch (DocumentException e) {
System.out.println(e.getMessage());
} catch (IOException e) {
System.out.println(e.getMessage());
}
}

/**
* xml转换为字符串
* @param doc
* @param encoding
* @return
* @throws Exception
*/
public static String toString(Document doc,String encoding)throws Exception{
OutputFormat format=OutputFormat.createPrettyPrint();
format.setEncoding(encoding);
ByteArrayOutputStream byteOS=new ByteArrayOutputStream();
XMLWriter writer = new XMLWriter(new OutputStreamWriter(byteOS,encoding),format);
writer.write(doc);
writer.flush();
writer.close();
writer=null;

return byteOS.toString(encoding);
}
/**
* 字符串转换为Document
* @param text
* @return
* @throws DocumentException
*/
public static Document str2Document(String text) throws DocumentException{
Document document = DocumentHelper.parseText(text);
return document;
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

}

}