Response Data Trong Spring Boot

1. Response Data với ResponseEntity

1.1 Tạo ResponseSuccess để phản hồi nếu xử lý thành công

import com.fasterxml.jackson.annotation.JsonInclude;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.util.MultiValueMap;

public class ResponseSuccess extends ResponseEntity {

    public ResponseSuccess(HttpStatus status, String message) {
        super(new Payload(status.value(), message), HttpStatus.OK);
    }

    public ResponseSuccess(HttpStatus status, String message, Object data) {
        super(new Payload(status.value(), message, data), status);
    }

    public ResponseSuccess(Payload body, HttpStatus status) {
        super(body, status);
    }

    public ResponseSuccess(MultiValueMap<String, String> headers, HttpStatus status) {
        super(headers, status);
    }

    public ResponseSuccess(Payload payload, MultiValueMap<String, String> headers, int rawStatus) {
        super(payload, headers, rawStatus);
    }

    public ResponseSuccess(Payload payload, MultiValueMap<String, String> headers, HttpStatus status) {
        super(payload, headers, status);
    }

    public static class Payload {
        private final int status;
        private final String message;
        @JsonInclude(JsonInclude.Include.NON_NULL)
        private Object data;

        public Payload(int status, String message) {
            this.status = status;
            this.message = message;
        }

        public Payload(int status, String message, Object data) {
            this.status = status;
            this.message = message;
            this.data = data;
        }

        public int getStatus() {
            return status;
        }

        public String getMessage() {
            return message;
        }

        public Object getData() {
            return data;
        }
    }
}

1.2 Tạo ResponseFailure để phản hồi nếu xử lý thất bại

public class ResponseFailure extends ResponseSuccess{
    public ResponseFailure(HttpStatus status, String message) {
        super(status, message);
    }
}

1.3 Áp dụng ResponseSuccess và ResponseFailure tại controller.

import jakarta.validation.Valid;
import jakarta.validation.constraints.Min;
import org.springframework.http.HttpStatus;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
import vn.tayjava.dto.request.UserRequestDTO;
import vn.tayjava.dto.response.ResponseFailure;
import vn.tayjava.dto.response.ResponseSuccess;

import java.util.List;

@RestController
@RequestMapping("/user")
@Validated
public class UserController {

    @PostMapping("/")
    public ResponseSuccess addUser(@Valid @RequestBody UserRequestDTO user) {
        System.out.println("Request add user " + user.getFirstName());
        
        try {
            return new ResponseSuccess(HttpStatus.CREATED, "User added successfully,", 1);
        } catch (Exception e) {
            return new ResponseFailure(HttpStatus.BAD_REQUEST, e.getMessage());
        }
    }

    @PutMapping("/{userId}")
    public ResponseSuccess updateUser(@PathVariable @Min(1) int userId, @Valid @RequestBody UserRequestDTO user) {
        System.out.println("Request update userId=" + userId);
       
        try {
            return new ResponseSuccess(HttpStatus.ACCEPTED, "User updated successfully");
        } catch (Exception e) {
            return new ResponseFailure(HttpStatus.BAD_REQUEST, e.getMessage());
        }
    }

    @PatchMapping("/{userId}")
    public ResponseSuccess updateStatus(@Min(1) @PathVariable int userId, @RequestParam boolean status) {
        System.out.println("Request change status, userId=" + userId);
        
        try {
            return new ResponseSuccess(HttpStatus.ACCEPTED, "User's status changed successfully");
        } catch (Exception e) {
            return new ResponseFailure(HttpStatus.BAD_REQUEST, e.getMessage());
        }
    }

    @DeleteMapping("/{userId}")
    public ResponseSuccess deleteUser(@PathVariable @Min(value = 1, message = "userId must be greater than 0") int userId) {
        System.out.println("Request delete userId=" + userId);

        try {
            return new ResponseSuccess(HttpStatus.NO_CONTENT, "User deleted successfully");
        } catch (Exception e) {
            return new ResponseFailure(HttpStatus.BAD_REQUEST, e.getMessage());
        }
    }

    @GetMapping("/{userId}")
    public ResponseSuccess getUser(@PathVariable @Min(1) int userId) {
        System.out.println("Request get user detail, userId=" + userId);
        
        try {
            return new ResponseSuccess(HttpStatus.OK, "user", new UserRequestDTO("Tay", "Java", "admin@tayjava.vn", "0123456789"));
        } catch (Exception e) {
            return new ResponseFailure(HttpStatus.BAD_REQUEST, e.getMessage());
        }
    }

    @GetMapping("/list")
    public ResponseSuccess getAllUser(@RequestParam(defaultValue = "0", required = false) int pageNo,
                                                         @Min(10) @RequestParam(defaultValue = "20", required = false) int pageSize) {
        System.out.println("Request get all of users");
        return new ResponseSuccess(HttpStatus.OK, "users", List.of(new UserRequestDTO("Tay", "Java", "admin@tayjava.vn", "0123456789"),
                new UserRequestDTO("Leo", "Messi", "leomessi@email.com", "0123456456")));
    }
}

2. Response Data với Generic

2.1 Tạo class ResponseData với kiểu generic là kiểu T để nhận mọi kiểu data type khác nhau trả về kết quả nếu như xử lý thành công.

import com.fasterxml.jackson.annotation.JsonInclude;

public class ResponseData {
    private final int status;
    private final String message;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private T data;

    /**
     * Response data for the API to retrieve data successfully. For GET, POST only
     * @param status
     * @param message
     * @param data
     */
    public ResponseData(int status, String message, T data) {
        this.status = status;
        this.message = message;
        this.data = data;
    }

    /**
     * Response data when the API executes successfully or getting error. For PUT, PATCH, DELETE
     * @param status
     * @param message
     */
    public ResponseData(int status, String message) {
        this.status = status;
        this.message = message;
    }

    public int getStatus() {
        return status;
    }

    public String getMessage() {
        return message;
    }

    public T getData() {
        return data;
    }
}

2.2 Tạo class ResponseError kế thừa từ ResponseData để nhận phản hồi nếu xử lý thất bại

public class ResponseError extends ResponseData {

    public ResponseError(int status, String message) {
        super(status, message);
    }
}

2.3 Áp dụng ResponseData và ResponseError tại UserController.

@RestController
@RequestMapping("/user")
@Validated
public class UserController {

    @PostMapping("/")
    public ResponseData addUser(@Valid @RequestBody UserRequestDTO user) {
        System.out.println("Request add user " + user.getFirstName());
        return new ResponseData<>(HttpStatus.CREATED.value(), "User added successfully,", 1);
    }

    @PutMapping("/{userId}")
    public ResponseData<?> updateUser(@PathVariable @Min(1) int userId, @Valid @RequestBody UserRequestDTO user) {
        System.out.println("Request update userId=" + userId);
        return new ResponseData<>(HttpStatus.ACCEPTED.value(), "User updated successfully");
    }

    @PatchMapping("/{userId}")
    public ResponseData<?> updateStatus(@Min(1) @PathVariable int userId, @RequestParam boolean status) {
        System.out.println("Request change status, userId=" + userId);
        return new ResponseData<>(HttpStatus.ACCEPTED.value(), "User's status changed successfully");
    }

    @DeleteMapping("/{userId}")
    public ResponseData<?> deleteUser(@PathVariable @Min(value = 1, message = "userId must be greater than 0") int userId) {
        System.out.println("Request delete userId=" + userId);
        return new ResponseData<>(HttpStatus.NO_CONTENT.value(), "User deleted successfully");
    }

    @GetMapping("/{userId}")
    public ResponseData getUser(@PathVariable @Min(1) int userId) {
        System.out.println("Request get user detail, userId=" + userId);
        return new ResponseData<>(HttpStatus.OK.value(), "user", new UserRequestDTO("Tay", "Java", "admin@tayjava.vn", "0123456789"));
    }

    @GetMapping("/list")
    public ResponseData<List> getAllUser(@RequestParam(defaultValue = "0", required = false) int pageNo,
                                                         @Min(10) @RequestParam(defaultValue = "20", required = false) int pageSize) {
        System.out.println("Request get all of users");
        return new ResponseData<>(HttpStatus.OK.value(), "users", List.of(new UserRequestDTO("Tay", "Java", "admin@tayjava.vn", "0123456789"),
                new UserRequestDTO("Leo", "Messi", "leomessi@email.com", "0123456456")));
    }
}

Xem video để được nghe hướng dẫn chi tiết từ Tây Java

Xem Source Code: https://github.dev/luongquoctay87/tayjava-sample-code/tree/bai-5-response-data

⇒ Lấy Source Code
$ git clone https://github.com/luongquoctay87/tayjava-sample-code.git
$ git checkout bai-5-response-data