How to exclude other class objects in a GET request? - Java Spring Boot

Question

I'm writing a simple GameShop Spring Boot CRUD service application. I have 3 classes Game, Customer, Order. The Order class has both the Game and Customer object.

public class Game {

    @JsonView(View.Summary.class)
    private int id;
    @JsonView(View.Summary.class)
    private String name;
    private String genre;
    private String platform;
    @JsonView(View.Summary.class)
    private String price;
    private String developer;
}

public class Customer {

    @JsonView(View.Summary.class)
    private int id;
    @JsonView(View.Summary.class)
    private String name;
    @JsonView(View.Summary.class)
    private String email;
    private String phoneNumber;
}

public class Order {

    @JsonView(View.Summary.class)
    private int id;
    @JsonView(View.Summary.class)
    private Date orderDate; // Mby string idk
    @JsonView(View.Summary.class)
    private boolean completed;
    private Game game;
    private Customer customer;
}

The problem is when I do a GET request like http://localhost:8080/orders it responds with the Game and Customer objects included as well like this:

"_embedded": {
    "orderList": [
        {
            "id": 1,
            "orderDate": "2019-03-04T20:12:20.207+0000",
            "completed": false,
            "game": {
                "id": 1,
                "name": "Persona 5",
                "genre": "JRPG",
                "platform": "PS4",
                "price": "59.99",
                "developer": "Atlus"
            },
            "customer": {
                "id": 1,
                "name": "Jonas",
                "email": "Jonas123@gmail.com",
                "phoneNumber": "867492455"
            }
        },
        {
            "id": 2,
            "orderDate": "2019-03-04T20:12:20.207+0000",
            "completed": false,
            "game": {
                "id": 2,
                "name": "Red dead redemption 2",
                "genre": "Action Adventure",
                "platform": "PS4",
                "price": "59.99",
                "developer": "Rockstar"
            },
            "customer": {
                "id": 2,
                "name": "Petras",
                "email": "Petras123@gmail.com",
                "phoneNumber": "867296545"
            }
        },
        {
            "id": 3,
            "orderDate": "2019-03-04T20:12:20.207+0000",
            "completed": false,
            "game": {
                "id": 3,
                "name": "XCOM 2",
                "genre": "Strategy",
                "platform": "PC",
                "price": "49.99",
                "developer": "Dev3"
            },
            "customer": {
                "id": 3,
                "name": "Zilvinas",
                "email": "Zilve123@gmail.com",
                "phoneNumber": "869444455"
            }
        }
    ]
},
"_links": {
    "self": {
        "href": "http://localhost:8080/orders"
    }
}

}

Meanwhile, I would like just to have links to them instead, for example http://localhost:8080/game/1 http://localhost:8080/customer/1 for the first order but I'm unsure how to exclude the objects themselves. I tried with @JsonView, but it just responds with and empty Json object.

Here is my controller for Order

@RestController
public class OrderController {

    @Autowired
    private OrderService orderService;

    //@JsonView(View.Summary.class) // commented out because gives empty response
    @GetMapping("/orders")
    public ResponseEntity<Resources<Order>>getAllOrders(){

    List<Order> orders = orderService.getAllOrders();
    Resources<Order> resources = new Resources<Order>(orders);
    Link linkTo = 
linkTo(methodOn(this.getClass()).getAllOrders()).withSelfRel();
    resources.add(linkTo);
    return ResponseEntity.ok(resources);
    }

    @GetMapping("/orders/{orderId}")
    public Order getOrderById(@PathVariable int orderId) {
        return orderService.getOrderById(orderId);
    }
}

Also, my View class

public class View {
    public interface Summary {}
}

Also, I'm not using any database for now and have all of the object instances in static blocks of the CustomerService, OrderService, GameService classes.

private static List <Order> orders = new ArrayList<Order>();
private static List <Game> games = new ArrayList<Game>();
private static List <Customer> customers = new ArrayList<Customer>();

static {
    GameService gameService = new GameService();
    CustomerService customerService = new CustomerService();
    games = gameService.getAllGames();
    customers = customerService.getAllCustomers();

    Order order1 = new Order(1,new Date(),false,games.get(0),customers.get(0));
    Order order2 = new Order(2,new Date(),false,games.get(1),customers.get(1));
    Order order3 = new Order(3,new Date(),false,games.get(2),customers.get(2));

    orders.add(order1);
    orders.add(order2);
    orders.add(order3);

}

Lastly, I would still want when passed some type of argument to the GET request that it would show all the information(with the objects included)

I'm stuck for a few days now and have no other ideas. Any suggestions would be appreciated.

Thank you.

EDIT

After adding @JsonIgnore to the getters the Game and Customer do not appear in the Json response anymore. I would still like if anyone can help me with the JsonView and what additional steps do I need to take for it not to return an empty object "{}"(when accessing /orders). Also updated my OrderController.

Answer 1

Use @JsonIgnore for ignore object in response

@JsonIgnore
private Game game;

@JsonIgnore
private Customer customer;

Answer 2

在这种情况下，不要使用@JsonIgnore，只需创建一个单独的DTO，并包含所需的字段并在其中设置数据后返回即可。