JDOM中XPath.selectNodes()和XPath.selectSingNodes()用法

JDOM中XPath.selectNodes()是返回一个节点集；而XPath.selectSingleNode()是返回符合要求的第一条记录。

1.测试用的message.xml文件：

Java代码

1. <?xml version="1.0" encoding="UTF-8"?>   
2. <root>   
3.     <person id="1">   
4.         <username ip="11111">xiaoma</username>   
5.         <password>xiaoma</password>   
6.     </person>   
7.     <person id="2">   
8.         <username ip="22222">manager</username>   
9.         <password>password2</password>   
10.     </person>   
11.     <person id="3">   
12.         <username ip="33333">manager</username>   
13.         <password>3333</password>   
14.     </person>   
15.     <hello id="999">   
16.         <username ip="22444">hello</username>   
17.         <password>world</password>   
18.     </hello>   
19.        
20. </root>  

<?xml version="1.0" encoding="UTF-8"?><root><person id="1"><username ip="11111">xiaoma</username><password>xiaoma</password></person><person id="2"><username ip="22222">manager</username><password>password2</password></person><person id="3"><username ip="33333">manager</username><password>3333</password></person><hello id="999"><username ip="22444">hello</username><password>world</password></hello></root>

2.selectNodes()方法：

Java代码

1. public static void list() throws JDOMException, IOException {   
2.         SAXBuilder builder = new SAXBuilder();   
3.         String xmlPath = "./src/xmldom/message.xml";   
4.         // 获得文档对象   
5.         Document document = builder.build(xmlPath);   
6.         // 获得根节点   
7.         Element root = document.getRootElement();   
8.         List reslist = XPath.selectNodes(root, "/root/person");   
9.         System.out.println("size:"+reslist.size());   
10.         for(int i=0;i<reslist.size();i++){   
11.             Element e = (Element)list.get(i);   
12.             System.out.println("id:"+e.getAttributeValue("id"));   
13.             System.out.println("username:"+e.getChild("username").getText());   
14.             System.out.println("ip:"+e.getChild("username").getAttributeValue("ip"));   
15.             System.out.println("password:"+e.getChild("password").getText());   
16.             System.out.println("-------------------");   
17.         }   
18.            
19.     }  

public static void list() throws JDOMException, IOException {SAXBuilder builder = new SAXBuilder();String xmlPath = "./src/xmldom/message.xml";// 获得文档对象Document document = builder.build(xmlPath);// 获得根节点Element root = document.getRootElement();List reslist = XPath.selectNodes(root, "/root/person");System.out.println("size:"+reslist.size());for(int i=0;i<reslist.size();i++){Element e = (Element)list.get(i);System.out.println("id:"+e.getAttributeValue("id"));System.out.println("username:"+e.getChild("username").getText());System.out.println("ip:"+e.getChild("username").getAttributeValue("ip"));System.out.println("password:"+e.getChild("password").getText());System.out.println("-------------------");}}

运行结果：

Java代码

1. size:3  
2. id:1  
3. username:xiaoma   
4. ip:11111  
5. password:xiaoma   
6. -------------------   
7. id:2  
8. username:manager   
9. ip:22222  
10. password:password2   
11. -------------------   
12. id:3  
13. username:manager   
14. ip:33333  
15. password:3333  
16. -------------------  

size:3id:1username:xiaomaip:11111password:xiaoma-------------------id:2username:managerip:22222password:password2-------------------id:3username:managerip:33333password:3333-------------------

3.selectSingleNode()方法：

Java代码

1. Element e1 = (Element)XPath.selectSingleNode(root, "/root/hello/username");   
2. System.out.println("ip:"+e1.getAttributeValue("ip"));   
3. System.out.println("username:"+e1.getText());   
4. System.out.println("--------------");   
5. Element e2 = (Element)XPath.selectSingleNode(root, "/root/hello");   
6. System.out.println("id:"+e2.getAttributeValue("id"));   
7. System.out.println("ip:"+e2.getChild("username").getAttributeValue("ip"));   
8. System.out.println("username:"+e2.getChild("username").getText());   
9. System.out.println("password:"+e2.getChild("password").getText());  

Element e1 = (Element)XPath.selectSingleNode(root, "/root/hello/username");System.out.println("ip:"+e1.getAttributeValue("ip"));System.out.println("username:"+e1.getText());System.out.println("--------------");Element e2 = (Element)XPath.selectSingleNode(root, "/root/hello");System.out.println("id:"+e2.getAttributeValue("id"));System.out.println("ip:"+e2.getChild("username").getAttributeValue("ip"));System.out.println("username:"+e2.getChild("username").getText());System.out.println("password:"+e2.getChild("password").getText());

测试结果：

Java代码

1. ip:22444  
2. username:hello   
3. --------------   
4. id:999  
5. ip:22444  
6. username:hello   
7. password:world  

ip:22444username:hello--------------id:999ip:22444username:hellopassword:world