Spring Boot Basic Course 03- Implement crud operation

Only change UserService interface,  UserServiceImpl class, and UserController class

UserService interface

package com.sb.basic.service;

import java.util.List;
import java.util.Optional;

import com.sb.basic.model.User;

public interface UserService {
	
	List<User> userList();
	
	Optional<User> findOne(Long id);
	
	User addUser(User user);
	
	String deleteUser(Long id);
}

UserServiceImpl class

package com.sb.basic.service.impl;

import java.util.List;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.sb.basic.model.User;
import com.sb.basic.repository.UserRepository;
import com.sb.basic.service.UserService;

@Service
public class UserServiceImpl implements UserService {
	
	private UserRepository userRepository;
	
	//Better go with constructor injection so no need to put @Autwired again and again
	
	@Autowired
	public UserServiceImpl(UserRepository userRepository) {
		this.userRepository = userRepository;
	}
	
	@Override
	public List<User> userList() {
		return userRepository.findAll();
	}
	
	@Override
	public Optional<User> findOne(Long id) {
		return userRepository.findById(id);
	}

	@Override
	public User addUser(User user) {
		return userRepository.save(user);
	}

	@Override
	public String deleteUser(Long id) {
		userRepository.deleteById(id);;
		return "{'message':'User Deleted'}";
	}

	
}

Create UserController class

package com.sb.basic.coontroller;

import java.util.List;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
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.RestController;

import com.sb.basic.model.User;
import com.sb.basic.service.UserService;

@RestController
@RequestMapping("/user")
public class UserController {
	
	private UserService userService;
	
	@Autowired
	public UserController(UserService userService) {
		this.userService = userService;
	}
	
	@RequestMapping("/list")
	public List<User> userList(){
		return userService.userList();
	}
	
	@RequestMapping("/id/{id}")	
	public Optional<User> findOne(@PathVariable Long id){
		return userService.findOne(id);
	}
	
	@RequestMapping("/add")
	public User addUser(@RequestBody User user){
		return userService.addUser(user);
	}
	
	@RequestMapping("/delete/{id}")
	public String deleteUser(@PathVariable Long id){
		return userService.deleteUser(id);
	}

}

Check URL



01. User List - 
      Method - Get
      Link      - http://localhost:9080/springbootbasic/user/list


02. Delete User - 
      Method - Get

      Link- http://localhost:9080/springbootbasic/user/delete/3             

03. Find User By Id - 
      Method - Get

      Link  - http://localhost:9080/springbootbasic/user/id/1


04. Add User - 
      Method - Post

      Link      - http://localhost:9080/springbootbasic/user/add
         {
   "userId":"167",
           "userName":"Perera",
           "password":"dser"
         }

04.1 User Update

      Now we don't need to update method. We can use add          method. Request body must identified with id.

      Method -Post
      Link-http://localhost:9080/springbootbasic/user/add
      {
           "id","3"
   "userId":"167",
           "userName":"Perera",
           "password":"dser"

         }

Priyantha.samaraweera