Conversion between Java Object and Json

fastjson maven dependency

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>2.0.23</version>
</dependency>

1. Java Object TO Json Object

public class JSONTest{
    public static void main(String[] args) {
        User user = new User("John", "Male", 18);
 
        JSONObject jsonObject = (JSONObject) JSONObject.toJSON(user);        
    }
}

2. Java Object TO Json String

public class JSONTest{
    public static void main(String[] args) {
        User user = new User("John", "Male", 18);
 
        String userStr = JSONObject.toJSONString(user);        
    }
}

3. Json Object to Json String

public class JSONTest{
    public static void main(String[] args) {
        User user = new User("John", "Male", 18);
 
        JSONObject jsonObject = (JSONObject) JSONObject.toJSON(user);
        String jsonStr = jsonObject.toJSONString();
    }
}

4. Json Object TO Java Object

public class JSONTest{
    public static void main(String[] args) {
        User user1 = new User("John", "Male", 18);
 
        JSONObject jsonObject = (JSONObject) JSONObject.toJSON(user1);
        
        User user = JSONObject.toJavaObject(jsonObject, User.class);
    }
}

5. Json String TO Json Object

public class JSONTest{
    public static void main(String[] args) {
        String userStr = "{\"age\":18,\"name\":\"John\",\"sex\":\"Male\"}";
 
        JSONObject jsonObject1 = JSONObject.parseObject(userStr);
    }
}

6. Json String TO Java Object

public class JSONTest{
    public static void main(String[] args) {
        String userStr = "{\"age\":18,\"name\":\"John\",\"sex\":\"Male\"}";
 
        User user = JSONObject.parseObject(userStr, User.class);
    }
}