RestAPI 创建嵌套 Json

Question

I followed this link: https://spring.io/guides/gs/rest-service/ to develop a REST API for my game. Based on this, I made a "template" REST API for my game. This is the code I wrote:

RestServiceApplication.java:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
    public class RestServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(RestServiceApplication.class, args);
    }

}

RESTAPIState.java:

public class RestAPIState {

    private String id;
    private int[] location = new int[2];
    private int points;

    public RestAPIState (String id, int[] location, int points) {
        this.id = id;
        this.location = location;
        this.points = points;
    }

    public String getId() {
        return id;
    }

    public int[] getLocation() {
        return location;
    }

    public int getPoints() {
       return points;
    }


}

RestAPIController.java:

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class RestAPIController {

    @GetMapping("/game")
    public RestAPIState greeting() {
        int[] sample = new int[2];
        sample[0] = 1;
        sample[1] = 2;
        return new RestAPIState("123", sample, 5);
    }

}

When I go to http://localhost:8080/game , I get the output "{"id":"123","location":[1,2],"points":5}", as expected. However, for my game I need to know how to know how to write a function which takes input and outputs nested JSON (unlike above) such as "{"player1": {"id": (input), "location": (input), "points": (input)}, "player2": ...}". Could someone please explain to me how to do this? Thank you so much.

Answer 1

You would need a class that models your use case in terms of information to be sent to the REST API. Something along the following lines:

public class YourNestedClass {
    private RestAPIState player1;
    private RestAPIState player2;
    // ...
}

And then you need to use this class as the parameter of the POST endpoint in your Controller:

@RestController
public class RestAPIController {

    @PostMapping("/whatever-path")
    public YourResponseClass whatever(@RequestBody YourNestedClass yourNestedClass) {
        (...)
    }

}