08 데이터 생성 with JPA
# 데이터 생성 with JPA
## 미션
JPA를 활용하여 폼 데이터를 DB로 저장하시오.
## 03:49 DTO를 엔티티로 변환하기
#### ../controller/ArticleController
```
...
@Controller
public class ArticleController {
...
@PostMapping("/articles/create")
public String createArticle(ArticleForm form) {
System.out.println(form.toString());
// 1. Dto를 Entity 변환
Article article = form.toEntity();
// 2. Repository에게 Entity를 DB로 저장하게 함
return "";
}
}
```
## 04:17 엔티티 작성하기
#### ../entity/Article
```
package com.example.firstproject.entity;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
@Entity
public class Article {
@Id
@GeneratedValue
private Long id;
@Column
private String title;
@Column
private String content;
public Article(Long id, String title, String content) {
this.id = id;
this.title = title;
this.content = content;
}
@Override
public String toString() {
return "Article{" +
"id=" + id +
", title='" + title + '\'' +
", content='" + content + '\'' +
'}';
}
}
```
## 07:17 변환 메소드 추가
#### ../dto/ArticleForm
```
package com.example.firstproject.dto;
import com.example.firstproject.entity.Article;
public class ArticleForm {
...
public Article toEntity() {
return new Article(null, title, content);
}
}
```
## 08:32 리파지터리를 통한 엔티티 저장하기
#### ../controller/ArticleController
```
package com.example.firstproject.controller;
import com.example.firstproject.dto.ArticleForm;
import com.example.firstproject.entity.Article;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
@Controller
public class ArticleController {
private ArticleRepository articleRepository;
...
@PostMapping("/articles/create")
public String createArticle(ArticleForm form) {
System.out.println(form.toString());
// 1. Dto를 Entity 변환
Article article = form.toEntity();
// 2. Repository에게 Entity를 DB로 저장하게 함
Article saved = articleRepository.save(article);
return "";
}
}
```
## 09:30 리파지터리 작성
#### ../repository/ArticleRepository
```
package com.example.firstproject.repository;
import com.example.firstproject.entity.Article;
import org.springframework.data.repository.CrudRepository;
public interface ArticleRepository extends CrudRepository<Article, Long> {
}
```
## 13:42 의존성 주입하기(DI)
#### ../controller/ArticleController
```
package com.example.firstproject.controller;
import com.example.firstproject.dto.ArticleForm;
import com.example.firstproject.entity.Article;
import com.example.firstproject.repository.ArticleRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
@Controller
public class ArticleController {
@Autowired // 스프링 부트가 미리 생성해놓은 리파지터리 객체를 가져옴(DI)
private ArticleRepository articleRepository;
...
@PostMapping("/articles/create")
public String createArticle(ArticleForm form) {
System.out.println(form.toString());
// 1. Dto를 Entity 변환
Article article = form.toEntity();
// 2. Repository에게 Entity를 DB로 저장하게 함
Article saved = articleRepository.save(article);
return "";
}
}
```
## 15:14 데이터 저장 흐름 확인
#### ../controller/ArticleController
```
package com.example.firstproject.controller;
import com.example.firstproject.dto.ArticleForm;
import com.example.firstproject.entity.Article;
import com.example.firstproject.repository.ArticleRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
@Controller
public class ArticleController {
@Autowired
private ArticleRepository articleRepository;
@GetMapping("/articles/new")
public String newArticleForm() {
return "articles/new";
}
@PostMapping("/articles/create")
public String createArticle(ArticleForm form) {
System.out.println(form.toString());
// 1. Dto를 Entity 변환
Article article = form.toEntity();
System.out.println(article.toString());
// 2. Repository에게 Entity를 DB로 저장하게 함
Article saved = articleRepository.save(article);
System.out.println(saved.toString());
return "";
}
}
```
## 🔥 구글링 훈련하기
- JPA 개념
- JPA 리파지터리란
- JPA Entity 사용법
- @Entity
- @Table
- @Id
- @GeneratedValue
- @Column
- DTO Entity 분리 장점
- JPA CrudRepository
- @Autowired