Dom4J使用XPath解析XMl

//需要导入包dom4j.jar jaxen.jar

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.Node;

/**
* @author fanggt
* xml解析
*/
public class XmlUtils {

//文档
private static Document doc = null;
//根节点
private static Element root = null;

public static void init(String xml){
//SAXReader reader = new SAXReader();
try {
doc = DocumentHelper.parseText(xml);
root = doc.getRootElement();
} catch (DocumentException e) {
e.printStackTrace();
}
}

/**
* 获取名称为nodeName的文本
* @param nodeName
* @return
*/
public static String getNodeText(String nodeName){
Node n = root.selectSingleNode("//"+nodeName);
return n.getText();
}

/**
* 获取所有名称为nodeName的节点
* @param nodeName
* @return
*/
@SuppressWarnings("unchecked")
public static List<Node> getNodeList(String nodeName){
return root.selectNodes("//"+nodeName);
}

/**
* 获取节点名称为nodeName的attrName属性
* @param nodeName
* @param attrName
* @return
*/
public static String getNodeAttribute(String nodeName,String attrName){
Node node = root.selectSingleNode("//"+nodeName);
return node.valueOf("@"+attrName);
}

/**
* 获取节点名称为nodeName的attrName属性
* @param nodeName
* @param attrName
* @return
*/
@SuppressWarnings("unchecked")
public static String getNodeAttribute(String nodeName,String attrName,int index){
List<Node> nodes = root.selectNodes("//"+nodeName+"[@"+attrName+"]");
return nodes.get(index).valueOf("@"+attrName);
}

/**
* 获取节点名称为nodeName的attrName属性 条件：改节点里面有个属性为key值为value的属性
* @param nodeName
* @param attrName
* @return
*/
@SuppressWarnings("unchecked")
public static String getNodeAttribute(String nodeName,String attrName,String key,String value){
List<Node> nodes = root.selectNodes("//"+nodeName+"[@"+key+"='"+value+"']");
return nodes.get(0).valueOf("@"+attrName);
}
/**
* @param args
*/
public static void main(String[] args) throws Exception{
File file  = new File("src/111.xml");
InputStreamReader isr = new InputStreamReader(new FileInputStream(file), "UTF-8");  
BufferedReader br = new BufferedReader(isr);  
//BufferedReader br = new BufferedReader(new FileReader(file));
String temp = null;
StringBuffer buffer = new StringBuffer();
while((temp=br.readLine())!=null){
buffer.append(temp).append("\n");
}
System.out.println(buffer);
XmlUtils.init(buffer.toString());
//String str = XmlUtils.getNodeText("RESPONSECONTENT");//获取只有一个的节点的text
//String str = XmlUtils.getNodeAttribute("RESPONSE-INFO", "SERNUM");//获取只有一个节点的属性
//String str = XmlUtils.getNodeAttribute("CARDPRICES", "STOCKNUM",1);//获取多个节点的第二个属性
String str = XmlUtils.getNodeAttribute("CARDPRICES", "STOCKNUM","CARDAMT","2990");//获取多个节点cardAmt=2990的stocknum的属性
System.out.println(str);
}

}