1, guide dependence

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.47</version>
        </dependency>

2, create a Pojo object ()

public class Myuser {
    private int id;
    private String username;
    private String userpwd;
    private String usersex;
    private Integer version;
    private Date createTime;
    private Date updateTime;
}

3. Initialization of the object "Boss" in the test method

        Myuser myuser1 = new Myuser();
        myuser1.setId(1);
        Myuser1.setUsername ("Boss");
        myuser1.setUsersex("male");
        myuser1.setUserpwd("123");

4, transform "boss"

JSON.toJSONString Convert "Boss" to JSON format String:

String receiverOfPOJO = JSON.toJSONString(myuser1);
System.out.println(receiverOfPOJO);

Output results:

{"ID": 1, "Username": "Boss", "UserPwd": "123", "Usersex": "Male"}

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Plus: Why do you use myuser1.toString ()?

System.out.println(myuser1.toString());

Output

Myuser (id = 1, username = boss, userpwd = 123, usersex = Male, Version = null, createtime = null, updatetime = null)

Contrast discovery: toString () method does not meet the JSON format, and JSON converted characters will ignore the attributes of the NULL. For example, you will find that we have not assigned to Version, and you can't see the JSON string. .

---

 

JSONObject.parseObjectTransform the "boss" of the String type to a Myuser type (note that the Myuser.class is passed, telling ParseObject to convert the target type):

Myuser receiverOfJSONObject = JSONObject.parseObject(receiverOfPOJO, Myuser.class);
System.out.println(myuser1.equals(receiverOfJSONObject));

Output result

true

 

5, build "old two", generate a list object

        Myuser myuser2 = new Myuser();
        myuser2.setId(2);
                 Myuser2.setusername ("old two");
        myuser2.setUsersex("male");
        myuser2.setUserpwd("abc");

        List<Myuser> myusers = new ArrayList<>();
        myusers.add(myuser1);
        myusers.add(myuser2);

6, convert LIST

JSON.toJSONString Convert List objects to JSON format strings

String receiverOfList = JSON.toJSONString(myusers);
System.out.println(receiverOfList);
System.out.println(myusers.toString());

Output:

[{"ID": 1, "UserName": "UserPwd": "123", "Usersex": "Male"}, {"ID": 2, "Username": "Old 2", " UserPwd ":" ABC "," Usersex ":" Male "}]
 [Myuser (id = 1, username = boss, userpwd = 123, usersex = malec, version = null, createtime = null, updatetime = null), myuser (id = 2, username = old two, userpwd = ABC, usersex = Male , Version = null, createtime = null, updatetime = null)]

Still comparing the string of the JSON converted string and the TOSTRING method to discovery differences.

 

 

 JSONArray.parseArrayConvert JSON format List strings to list <user>

List<Myuser> receiverOfJSONList = JSONArray.parseArray(receiverOfList,Myuser.class);
System.out.println(receiverOfJSONList.equals(myusers));

Output:

true