对象转json

 <dependency>  
   <groupId>com.alibaba</groupId>  
   <artifactId>fastjson</artifactId>  
   <version>1.1.36</version>  
      </dependency> 


 User user = new User(100 , "shishi"); 
    String json = JSON.toJSONString(user);  
    System.out.println(json);




 <dependency>
    <groupId>net.sf.json-lib</groupId>
    <artifactId>json-lib-ext-spring</artifactId>
    <version>1.0.2</version>
   </dependency>


JSONArray jsonArray2 = JSONArray.fromObject(list);
System.out.println(jsonArray2);