XML解析为对象

jaxb解析xml为对象例子

文章分类:Java编程

通过jaxb方式把xml文件映射成bean对象。

1、新建java工程或者web工程都可以。
2、通过精简必须导入jar包
         activation.jar
        jaxb-api-2.0.jar
        jaxb-impl-2.0.1.jar
        jsr173_api-1.0.jar
3、 新建xml文件
    <?xml version="1.0" encoding="UTF-8"?>
    <root>

<template
   start="true"
   ip="127.0.0.1"
   port="3344"
   server="server"
/>
<template ... ... />
    </root>

4、新建bean对象，xml的映射文件。
Vo.java 如下
  

Java代码

1. import javax.xml.bind.annotation.XmlAccessType;   
2. import javax.xml.bind.annotation.XmlAccessorType;   
3. import javax.xml.bind.annotation.XmlAttribute;   
4. import javax.xml.bind.annotation.XmlRootElement;   
5. import javax.xml.bind.annotation.XmlType;   
6.   
7. @XmlAccessorType(XmlAccessType.FIELD)   
8. @XmlType(name = "", propOrder = {   
9. })   
10. @XmlRootElement(name = "[color=red]template[/color]")   
11. public class Vo {   
12.   
13.     @XmlAttribute  
14.     private String start;   
15.     @XmlAttribute  
16.     private String ip;   
17.     @XmlAttribute  
18.     private String port;   
19.     @XmlAttribute  
20.     private String server;   
21.        
22.        
23.     public String getStart() {   
24.         return start;   
25.     }   
26.     public void setStart(String start) {   
27.         this.start = start;   
28.     }   
29.     public String getIp() {   
30.         return ip;   
31.     }   
32.     public void setIp(String ip) {   
33.         this.ip = ip;   
34.     }   
35.     public String getPort() {   
36.         return port;   
37.     }   
38.     public void setPort(String port) {   
39.         this.port = port;   
40.     }   
41.     public String getServer() {   
42.         return server;   
43.     }   
44.     public void setServer(String server) {   
45.         this.server = server;   
46.     }   
47. }   
48.      

import javax.xml.bind.annotation.XmlAccessType;import javax.xml.bind.annotation.XmlAccessorType;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlRootElement;import javax.xml.bind.annotation.XmlType;@XmlAccessorType(XmlAccessType.FIELD)@XmlType(name = "", propOrder = {})@XmlRootElement(name = "[color=red]template[/color]")public class Vo {@XmlAttributeprivate String start;@XmlAttributeprivate String ip;@XmlAttributeprivate String port;@XmlAttributeprivate String server;public String getStart() {return start;}public void setStart(String start) {this.start = start;}public String getIp() {return ip;}public void setIp(String ip) {this.ip = ip;}public String getPort() {return port;}public void setPort(String port) {this.port = port;}public String getServer() {return server;}public void setServer(String server) {this.server = server;}}   

该文件对应xml文件中 循环节点 template 元素

Root.java 文件如下

Java代码

1. import java.util.ArrayList;   
2. import java.util.List;   
3.   
4. import javax.xml.bind.annotation.XmlAccessType;   
5. import javax.xml.bind.annotation.XmlAccessorType;   
6. import javax.xml.bind.annotation.XmlRootElement;   
7. import javax.xml.bind.annotation.XmlType;   
8.   
9. @XmlAccessorType(XmlAccessType.FIELD)   
10. @XmlType(name = "", propOrder = {   
11. })   
12. @XmlRootElement(name = "[color=blue]root[/color]")   
13. public class Root {   
14.        
15.     protected List<Vo> [color=red]template[/color];   
16.        
17.     public List<Vo> getTemplateList() {   
18.         if (template == null) {   
19.             template = new ArrayList<Vo>();   
20.         }   
21.         return this.template;   
22.     }   
23. }  

import java.util.ArrayList;import java.util.List;import javax.xml.bind.annotation.XmlAccessType;import javax.xml.bind.annotation.XmlAccessorType;import javax.xml.bind.annotation.XmlRootElement;import javax.xml.bind.annotation.XmlType;@XmlAccessorType(XmlAccessType.FIELD)@XmlType(name = "", propOrder = {})@XmlRootElement(name = "[color=blue]root[/color]")public class Root {protected List<Vo> [color=red]template[/color];public List<Vo> getTemplateList() {        if (template == null) {        template = new ArrayList<Vo>();        }        return this.template;    }}

注意bean对象与xml映射的关系。

5、 解析xml为bean类

Java代码

1. public static void gernateConfig() throws Exception{   
2.         StringBuffer buffer  = null;   
3.         JAXBContext jaxbContext;   
4.         try {   
5.                            //读入xml文件流   
6.                            InputStream is = Excecute.class.getResourceAsStream(“/conf/config.xml”);   
7.             BufferedReader in = new BufferedReader(new InputStreamReader(is));   
8.             buffer = new StringBuffer();   
9.             String line = "";   
10.             while ((line = in.readLine()) != null) {   
11.                 buffer.append(line);   
12.             }   
13.                
14.             //加载映射bean类   
15.             jaxbContext = JAXBContext.newInstance(Root.class);   
16.                            //创建解析   
17.             Unmarshaller um = jaxbContext.createUnmarshaller();   
18.             StreamSource streamSource = new StreamSource(new StringReader(buffer.toString()));   
19.             Root root = (Root) um.unmarshal(streamSource);    
20.         } catch (Exception e) {   
21.             e.printStackTrace();   
22.             throw new Exception(e.getMessage());   
23.         }   
24.     }  

public static void gernateConfig() throws Exception{StringBuffer buffer  = null;JAXBContext jaxbContext;try {                           //读入xml文件流                           InputStream is = Excecute.class.getResourceAsStream(“/conf/config.xml”);BufferedReader in = new BufferedReader(new InputStreamReader(is));buffer = new StringBuffer();String line = "";while ((line = in.readLine()) != null) {buffer.append(line);}//加载映射bean类jaxbContext = JAXBContext.newInstance(Root.class);                           //创建解析Unmarshaller um = jaxbContext.createUnmarshaller();StreamSource streamSource = new StreamSource(new StringReader(buffer.toString()));Root root = (Root) um.unmarshal(streamSource); } catch (Exception e) {e.printStackTrace();throw new Exception(e.getMessage());}}

6、 把bean对象生成xml字符串方法

Java代码

1. public static String gernateConfigXml(Root root) throws Exception {   
2.         if (root != null) {   
3.             try {   
4.                 JAXBContext context = JAXBContext.newInstance(Root.class);   
5.                 Marshaller m = context.createMarshaller();   
6.                 m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);   
7.                 Writer writer = new StringWriter();   
8.                 m.marshal(root, writer);   
9.                 try {   
10.                     String xml = writer.toString();   
11.                     writer.flush();   
12.                     writer.close();   
13.                     return xml;   
14.                 } catch (IOException e) {   
15.                     return "";   
16.                 }   
17.             } catch (Exception e) {   
18.                 throw new Exception("失败!");   
19.             }   
20.         } else {   
21.             return null;   
22.         }   
23.     }  

public static String gernateConfigXml(Root root) throws Exception {if (root != null) {try {JAXBContext context = JAXBContext.newInstance(Root.class);Marshaller m = context.createMarshaller();m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);Writer writer = new StringWriter();m.marshal(root, writer);try {String xml = writer.toString();writer.flush();writer.close();return xml;} catch (IOException e) {return "";}} catch (Exception e) {throw new Exception("失败!");}} else {return null;}}