Spring Boot으로 웹 출시까지 #7. JPA이용한 RESTful API 작성

참고 사이트에서 REST 서비스를 Spring을 이용해서 다뤄보자.

 

• JPA를 이용해서 mariaDB의 데이터 조작할 수 있는 컨트롤러 생성

 

• PostMan을 이용해서 http요청을 통해 CRUD 데이터 조작하기 

 

 

참고 사이트

아래의 HTTP is the Platform을 사용해보자.

package payroll;

import java.util.List;

import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
class EmployeeController {

  private final EmployeeRepository repository;

  EmployeeController(EmployeeRepository repository) {
    this.repository = repository;
  }


  // Aggregate root
  // tag::get-aggregate-root[]
  @GetMapping("/employees")
  List<Employee> all() {
    return repository.findAll();
  }
  // end::get-aggregate-root[]

  @PostMapping("/employees")
  Employee newEmployee(@RequestBody Employee newEmployee) {
    return repository.save(newEmployee);
  }

  // Single item
  
  @GetMapping("/employees/{id}")
  Employee one(@PathVariable Long id) {
    
    return repository.findById(id)
      .orElseThrow(() -> new EmployeeNotFoundException(id));
  }

  @PutMapping("/employees/{id}")
  Employee replaceEmployee(@RequestBody Employee newEmployee, @PathVariable Long id) {
    
    return repository.findById(id)
      .map(employee -> {
        employee.setName(newEmployee.getName());
        employee.setRole(newEmployee.getRole());
        return repository.save(employee);
      })
      .orElseGet(() -> {
        newEmployee.setId(id);
        return repository.save(newEmployee);
      });
  }

  @DeleteMapping("/employees/{id}")
  void deleteEmployee(@PathVariable Long id) {
    repository.deleteById(id);
  }
}

 

 

 

 

 

Controller Package를 만들고 BoardApiController를 만들어주자.

만들어주고 localhost:8080/api/boards에 들어가주면 아래와 같이 나온다.

[{"id":1,"title":"제목","content":"내용"},{"id":2,"title":"헬로","content":"월드"}]

package com.example.myhome.controller;

import com.example.myhome.model.Board;
import com.example.myhome.repository.BoardRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/api")
class BoardApiController {

    @Autowired
    private BoardRepository repository;

    @GetMapping("/boards")
    List<Board> all() {
        return repository.findAll();
    }
    // end::get-aggregate-root[]

    @PostMapping("/boards")
    Board newBoard(@RequestBody Board newBoard) {
        return repository.save(newBoard);
    }

    // Single item

    @GetMapping("/boards/{id}")
    Board one(@PathVariable Long id) {
        return repository.findById(id).orElse(null);
    }

    @PutMapping("/boards/{id}")
    Board replaceBoard(@RequestBody Board newBoard, @PathVariable Long id) {

        return repository.findById(id)
                .map(Board -> {
                    Board.setTitle(newBoard.getTitle());
                    Board.setContent(newBoard.getContent());
                    return repository.save(Board);
                })
                .orElseGet(() -> {
                    newBoard.setId(id);
                    return repository.save(newBoard);
                });
    }

    @DeleteMapping("/boards/{id}")
    void deleteBoard(@PathVariable Long id) {
        repository.deleteById(id);
    }
}

 

 

제목으로 검색하는 api를 작성해보자.

package com.example.myhome.controller;

import com.example.myhome.model.Board;
import com.example.myhome.repository.BoardRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/api")
class BoardApiController {

    @Autowired
    private BoardRepository repository;

    @GetMapping("/boards")
    List<Board> all(@RequestParam(required = false) String title) {
        if(StringUtils.isEmpty(title)) {
            return repository.findAll();
        } else {
            return repository.findByTitle(title);
        }
    }

    @PostMapping("/boards")
    Board newBoard(@RequestBody Board newBoard) {
        return repository.save(newBoard);
    }

    // Single item

    @GetMapping("/boards/{id}")
    Board one(@PathVariable Long id) {
        return repository.findById(id).orElse(null);
    }

    @PutMapping("/boards/{id}")
    Board replaceBoard(@RequestBody Board newBoard, @PathVariable Long id) {

        return repository.findById(id)
                .map(Board -> {
                    Board.setTitle(newBoard.getTitle());
                    Board.setContent(newBoard.getContent());
                    return repository.save(Board);
                })
                .orElseGet(() -> {
                    newBoard.setId(id);
                    return repository.save(newBoard);
                });
    }

    @DeleteMapping("/boards/{id}")
    void deleteBoard(@PathVariable Long id) {
        repository.deleteById(id);
    }
}

 

 

BoardRepository도 아래와 같이 작성해준다.

package com.example.myhome.repository;

import com.example.myhome.model.Board;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface BoardRepository extends JpaRepository<Board, Long> {

    List<Board> findByTitle(String title);
}

 

BoardApiController Class 에 추가

@Autowired
    private BoardRepository repository;

    @GetMapping("/boards")
    List<Board> all(@RequestParam(required = false) String title,
        @RequestParam(required = false, defaultValue = "") String content) {
        if(StringUtils.isEmpty(title)) {
            return repository.findAll();
        } else {
            return repository.findByTitle(title);
        }
    }

 

BoardRepository Interface에 추가.

package com.example.myhome.repository;

import com.example.myhome.model.Board;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface BoardRepository extends JpaRepository<Board, Long> {

    List<Board> findByTitle(String title);

    List<Board> findByTitleOrContent(String title, String content);
}

 

BoardApiController에서 title이나 content에 해당하는 문자열을 or 조건으로 검색하는 코드를 작성해준다.

@GetMapping("/boards")
    List<Board> all(@RequestParam(required = false, defaultValue = "") String title,
        @RequestParam(required = false, defaultValue = "") String content) {
        if(StringUtils.isEmpty(title) && StringUtils.isEmpty(content)) {
            return repository.findAll();
        } else {
            return repository.findByTitleOrContent(title, content);
        }
    }

 

 

spring.io에서 spring data jpa를 확인해주자. 

 

query annotation도 참고해주자.(Declaring Interfaces 검색)

 

 

Postman을 이용해보자.

 

 

post로도 작성을 해주자. Body 부분을 JSON으로 세팅을 해주면 아래와 같고 post로 날린 table이 DB에서도 확인이 잘 된다.

 

console에서도 확인을 해주면 아래와 같다.

 

 

 

put으로 값을 변경해주면 아래와 같이 나온다.

 

 

 

마지막으로 Delete로 삭제도 해주자.

 

 

 

 

 

 

 

<참고 :Spring Boot으로 웹 출시까지 #7. JPA 이용한 RESTful API 작성>

https://www.youtube.com/watch?v=XHT6S5JH_RU&list=PLPtc9qD1979DG675XufGs0-gBeb2mrona&index=8