xstream:实现JavaBean与XML/JSON的相互转换

     XML和JSON是两种很常用的数据描述和传输格式，在java里提供了完成JavaBean与这两种格式相互转换的组件，即XStream和JSON-lib，通过组件实现可以使得转换省事很多。这里主要讲解xstream的实现。首先要加载xstream包，当前版本是1.3.1，即xstream-1.3.1.jar。

这里先举个最简单的例子：

JavaBean:

package xstream;

public class Person {
private int id;
private String name;
private int age;
        //这里省略setter和getter及构造方法
}

转换测试类：

package xstream;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.json.JsonHierarchicalStreamDriver;
import com.thoughtworks.xstream.io.xml.DomDriver;

public class Convert 
{
public static void main(String[] args) 
{
  Person person = new Person(1,"admin",20);
  XStream xstream = new XStream(new DomDriver());     
  xstream.alias("Person", Person.class);  
  String xml = xstream.toXML(person);//JavaBean->XML
  System.out.println(xml);   

  Person otherPerson = (Person) xstream.fromXML(xml);//XML->JavaBean
  System.out.println("id:"+otherPerson.getId());
  System.out.println("name:"+otherPerson.getName());
  System.out.println("age:"+otherPerson.getAge());

  XStream json = new XStream(new JsonHierarchicalStreamDriver()); 
  json.alias("Person", Person.class);    
  String js = json.toXML(person);//JavaBean->JSON
  System.out.println(js);
}
}

输出结果：

<Person>
  <id>1</id>
  <name>admin</name>
  <age>20</age>
</Person>

id:1
name:admin
age:20

{"Person": {
  "id": 1,
  "name": "admin",
  "age": 20
}}