javaBean List Map json（转）

1、依赖的包

根据：http://json-lib.sourceforge.net/ 可见json-lib使用需要依赖一下包：

 

下载地址：http://download.csdn.net/download/zfxinli/2117292  或百度盘：http://pan.baidu.com/s/1hq5kGQC

非常有用的参考：

（1）json在线转换器：http://json.parser.online.fr/

（2）json介绍：http://www.json.org/json-zh.html

2、普通JavaBean

（1）基本JavaBean

public class User {
    private String username;
    private String password;
    
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

（2）转化成JSONArray

User user = new User();
user.setUsername("lp");
user.setPassword("1234");
JSONArray json = JSONArray.fromObject(user);
System.out.println(json);
//结果：[{"password":"1234","username":"lp"}]

（3）转化成JSONObject

User user = new User();
user.setUsername("lp");
user.setPassword("1234");
JSONObject json = JSONObject.fromObject(user);
System.out.println(json);
//结果;{"password":"1234","username":"lp"}

3、List<User>

（1）转化成JSONArray

List<User>users = new ArrayList<>();
User user = new User();
user.setUsername("lp");
user.setPassword("1234");
User userSecond = new User();
userSecond.setUsername("ch");
userSecond.setPassword("4567");
users.add(user);
users.add(userSecond);
JSONArray json = JSONArray.fromObject(users);
System.out.println(json);
//结果：[{"password":"1234","username":"lp"},{"password":"4567","username":"ch"}]

（2）转化成JSONObject

不可以直接通过JSONObject jsonObj = JSONObject.fromObject(users);进行

可以通过如下方式：

JSONObject json = new JSONObject();
json.put("users", users);
json.put("userSecond", userSecond);
System.out.println(json);
//结果：{"users":[{"password":"1234","username":"lp"},{"password":"4567","username":"ch"}],"userSecond":{"password":"4567","username":"ch"}}

  

4、Map

（1）转化成JSONArray

Map<String, Object>map = new HashMap<String, Object>();
map.put("users", users);
map.put("user", user);
JSONArray json = JSONArray.fromObject(map);
System.out.println(json);
//结果：[{"users":[{"password":"1234","username":"lp"},{"password":"4567","username":"ch"}],"user":{"password":"1234","username":"lp"}}]

（2）转化成JSONObject

Map<String, Object>map = new HashMap<String, Object>();
map.put("users", users);
map.put("user", user);
JSONObject json = JSONObject.fromObject(map);
System.out.println(json);
//结果：{"users":[{"password":"1234","username":"lp"},{"password":"4567","username":"ch"}],"user":{"password":"1234","username":"lp"}}

来源：http://blog.sina.com.cn/s/blog_a15aa56901017i2x.html