使用JSONObject生成json 博客分类： Java JSON

所需要的包

commons-httpclient-3.1.jar

commons-lang-2.4.jar

commons-logging-1.1.1.jar

json-lib-2.4-jdk15.jar

ezmorph-1.0.6.jar

commons-collections-3.2.1.jar

 1、bean转为Json

User u = new User();
u.setAge(22);
u.setUsername("hzucmj");
u.setEnabled(true);

JSONObject json = JSONObject.fromObject(u);
System.out.println(json.toString()); //结果为：{"enabled":true,"username":"hzucmj","age":22}

2、List转为Json

User u1 = new User();
u1.setAge(22);
u1.setUsername("hzucmj");
u1.setEnabled(true);

User u2 = new User();
u2.setAge(20);
u2.setUsername("ctf");
u2.setEnabled(true);

List<Object> list = new ArrayList<Object>();
list.add(u1);</p>
list.add(u2);</p>

JSONArray json = JSONArray.fromObject(list);
System.out.println(json.toString()); //结果为：[{"enabled":false,"username":"ctf","age":20},{"enabled":false,"username":"","age":0}]

3、Map转为Json

HashMap<String, Comparable> map = new HashMap<String, Comparable>();
map.put("name", "hzucmj");
map.put("age", 22);
JSONObject json = JSONObject.fromObject(map);
System.out.println(json.toString()); //结果为：{"name":"hzucmj","age":22}