Code ví dụ Spring Boot RESTful Webservice (CRUD)

(Xem lại: Web Service là gì?)

(Xem lại: Giới thiệu về RESTful web service.)

(Xem lại: Code ví dụ, tạo RESTful Web Service với Spring MVC)

Các công nghệ sử dụng:

Tạo Spring Boot Project:

Cấu trúc Project

Khi tạo project Spring Boot nó sẽ tự động thêm các thư viện jackson để mapping dữ liệu trả về sang dạng JSON

File entities:

package stackjava.com.sbrestful.entities;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonInclude;

@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(value = { "password" })

public class User {
  private int id;
  private String username;
  private String password;

  public User() {
  }

  public User(int id, String username, String password) {
    this.id = id;
    this.username = username;
    this.password = password;
  }

  // getter - setter

}

Khi trả về đối tượng User mình sẽ bỏ qua trường password (thông tin nhạy cảm) và các trường bị null.

File Controller:

package stackjava.com.sbrestful.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class BaseController {

  @RequestMapping("/")
  public String index() {
    return "index";
  }

}

package stackjava.com.sbrestful.controller;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import stackjava.com.sbrestful.entities.User;

@RestController
@RequestMapping("/rest")
public class UserRestController {
  
   public static HashMap<Integer, User> mapUser = new HashMap<Integer, User>();
    static {
      mapUser.put(1, new User(1, "kai", "123456"));
      mapUser.put(2, new User(2, "admin", "admin1234"));
      mapUser.put(3, new User(3, "sena", "123456"));
      mapUser.put(4, new User(4, "peter", "1234"));
    }
    
    /* ---------------- GET ALL USER ------------------------ */
    @RequestMapping(value = "/users", method = RequestMethod.GET)
    public ResponseEntity<List<User>> getAllUser() {
      List<User> listUser = new ArrayList<User>(mapUser.values());
      return new ResponseEntity<List<User>>(listUser, HttpStatus.OK);
    }
    
    /* ---------------- GET USER BY ID ------------------------ */
    @RequestMapping(value = "/users/{id}", method = RequestMethod.GET)
    public ResponseEntity<Object> getUserById(@PathVariable int id) {
      User user = mapUser.get(id);
      if (user != null) {
        return new ResponseEntity<Object>(user, HttpStatus.OK);
      }
      return new ResponseEntity<Object>("Not Found User", HttpStatus.NO_CONTENT);
    }
    
    /* ---------------- CREATE NEW USER ------------------------ */
    @RequestMapping(value = "/users", method = RequestMethod.POST)
    public ResponseEntity<String> createUser(@RequestBody User user) {
      if (mapUser.containsKey(user.getId())) {
        return new ResponseEntity<String>("User Already Exist!", HttpStatus.CONFLICT);
      }
      mapUser.put(user.getId(), user);
      return new ResponseEntity<String>("Created!", HttpStatus.CREATED);
    }
    
    /* ---------------- DELETE USER ------------------------ */
    @RequestMapping(value = "/users/{id}", method = RequestMethod.DELETE)
    public ResponseEntity<String> deleteUserById(@PathVariable int id) {
      User user = mapUser.get(id);
      if (user == null) {
        return new ResponseEntity<String>("Not Found User", HttpStatus.OK);
      }
      
      mapUser.remove(id);
      return new ResponseEntity<String>("Deleted!", HttpStatus.OK);
    }
    
    /* ---------------- UPDATE USER ------------------------ */
    @RequestMapping(value = "/users", method = RequestMethod.PUT)
    public ResponseEntity<String> updateUser(@RequestBody User user) {
      User oldUser = mapUser.get(user.getId());
      if (oldUser == null) {
        return new ResponseEntity<String>("Not Found User", HttpStatus.NO_CONTENT);
      }
      
      // replace old user by new user.
      mapUser.put(user.getId(), user);
      return new ResponseEntity<String>("Updated!", HttpStatus.OK);
    }
    
}

File view:

<html>
<head>
</head>
<body>
  <h1>Demo Spring Boot RESTful Web Service</h1>
  <br />
  <a href="/rest/users">/users</a>
  <br />
  <a href="/rest/users/1">/users/1</a>
  <br />
</body>
</html>

Demo: