java读写xml文件

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;
public class Operate {
public static void main(String[] args) throws Exception
{
WriteXML(".//conf//12.xml", "searcher.dir", "123");
System.err.println(ReadXML(".//conf//12.xml","searcher.dir"));
}
public static String ReadXML(String path,String name) throws Exception{
DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
DocumentBuilder db=dbf.newDocumentBuilder();
InputStream is=new FileInputStream(path);
Document doc=db.parse(is);
Element root=doc.getDocumentElement();
NodeList datas=root.getChildNodes();
String str="";
if(datas!=null){
for(int i=0;i<datas.getLength();i++){
Node data=datas.item(i);
if(data.getNodeType()==Node.ELEMENT_NODE){
for(Node node=data.getFirstChild();node!=null;node=node.getNextSibling()){
if(node.getNodeType()==Node.ELEMENT_NODE){
if(node.getNodeName().equals("name")&&node.getTextContent().equals(name)){
NodeList nl=node.getParentNode().getChildNodes();
for (int k = 0; k <nl.getLength(); k++) {
if (nl.item(k).getNodeName().contains("value")) {
str=nl.item(k).getTextContent();
}
}
}
}
}
}
}
}
return str;
}

public static void WriteXML(String path,String name,String value){
DocumentBuilderFactory domfac=DocumentBuilderFactory.newInstance();
try {
DocumentBuilder dombuilder=domfac.newDocumentBuilder();
InputStream is=new FileInputStream(path);
Document doc=dombuilder.parse(is);
Element root=doc.getDocumentElement();
NodeList datas=root.getChildNodes();
if(datas!=null){
for(int i=0;i<datas.getLength();i++){
Node data=datas.item(i);
if(data.getNodeType()==Node.ELEMENT_NODE){
for(Node node=data.getFirstChild();node!=null;node=node.getNextSibling()){
if(node.getNodeName().equals("name")&&node.getTextContent().equals(name)){
NodeList nl=node.getParentNode().getChildNodes();
for (int k = 0; k <nl.getLength(); k++) {
if (nl.item(k).getNodeName().contains("value")) {
nl.item(k).setTextContent(value);
}
}
}
}
}
}
}
doc2XmlFile(doc, path);
System.err.println("success");
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static boolean doc2XmlFile(Document document, String filename) {
boolean flag = true;
try {

TransformerFactory tFactory = TransformerFactory.newInstance();
Transformer transformer = tFactory.newTransformer();
DOMSource source = new DOMSource(document);
StreamResult result = new StreamResult(new File(filename));
transformer.transform(source, result);
} catch (Exception ex) {
flag = false;
ex.printStackTrace();
}
return flag;
}
}

<?xml version="1.0" encoding="UTF-8" standalone="no"?><?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
<name>http.agent.name</name>
<value>my nutch agent</value>
</property>
<property>
<name>http.agent.version</name>
<value>1.2</value>
</property>
<property>
<name>searcher.dir</name>
<value>123</value>
<description>index dir</description>
</property>
</configuration>