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Spring Boot CRUD using JPA

info

Create a Project, practice CRUD using Spring-JPA.

使用 Spring-JPA 练习增删改查

Maven 配置​

pom.xml 配置文件​

...

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

...

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.modelmapper/modelmapper -->
        <dependency>
            <groupId>org.modelmapper</groupId>
            <artifactId>modelmapper</artifactId>
            <version>2.4.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
    </dependencies>

Spring Boot 配置文件​

server.port = 8080
# datasource
spring.datasource.url = jdbc:mysql://localhost:3306/iccblog?useSSL=false&serverTimezone=UTC
spring.datasource.username= ...
spring.datasource.password= ...

# hibernate properties
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5InnoDBDialect
# hibernate ddl auto(create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto = update


...

logging.level.org.springframework.security=DEBUG
spring.security.user.name=...
spring.security.user.password=...
spring.security.user.roles=ADMIN

## App Properties
app.jwt-secret= JWTSecretKeysds
app.jwt-expiration-milliseconds = 604800000

## Spring Profile: dev, prod
spring.profiles.active=dev

Spring Boot CRUD​

entity​

package com.chuwa.iccblog.entity;

@Entity
@Table(name = "posts", uniqueConstraints = {
        @UniqueConstraint(columnNames = {"title"})
})
public class Post {

    @Id
    @GeneratedValue(
            strategy = GenerationType.IDENTITY
    )
    private Long id;

    @Column(name = "title", nullable = false)
    private String title;

    @Column(name = "description", nullable = false)
    private String description;

    @Column(name = "content", nullable = false)
    private String content;

    @OneToMany(mappedBy = "post", cascade = CascadeType.ALL, orphanRemoval = true)
    private Set<Comment> comments = new HashSet<>();

    @CreationTimestamp
    private LocalDateTime createDateTime;

    @UpdateTimestamp
    private LocalDateTime updateDateTime;
}

// ...

dao​

package com.chuwa.iccblog.dao;

@Repository
public interface PostRepository extends JpaRepository<Post, Long> {

}

payload​

package com.chuwa.iccblog.payload;

public class PostDto {
    private long id;

    @NotEmpty
    @Size(min = 2, message = "Post title should have at least 2 characters")
    private String title;

    @NotEmpty
    @Size(min = 10, message = "Post description should have at least 10 characters")
    private String description;

    @NotEmpty
    private String content;
}

// ...
package com.chuwa.iccblog.payload;

public class PostResponse {
    private List<PostDto> content;
    private int pageNo;
    private int pageSize;
    private long totalElements;
    private int totalPages;
    private boolean last;
}

// ...

service and impl​

package com.chuwa.iccblog.service;

public interface PostService {
    PostDto createPost(PostDto postDto);

    PostDto getPostById(long id);

    PostDto updatePost(PostDto postDto, long id);

    void deletePostById(long id);

    // 分页查询
    PostResponse getAllPost(int pageNo, int pageSize, String sortBy, String sortDir);
}
package com.chuwa.iccblog.service.impl;

@Service
public class PostServiceImpl implements PostService {

    @Autowired
    private PostRepository postRepository;

    @Override
    public PostDto createPost(PostDto postDto) {
        // 把payload转换为entity，让 DAO 去把该数据存到数据库中
        // postDto pojo -> post entity
        Post post = new Post();
        post.setTitle(postDto.getTitle());
        post.setDescription(postDto.getDescription());
        post.setContent(postDto.getContent());

        // 已转换成 entity
        Post savedPost = postRepository.save(post);

        // 把 post entity对象转换为dto
        PostDto postResponse = new PostDto();
        postResponse.setId(savedPost.getId());
        postResponse.setDescription(savedPost.getDescription());
        postResponse.setTitle(savedPost.getTitle());
        postResponse.setContent(savedPost.getContent());

        return postResponse;
    }

    @Override
    public PostDto getPostById(long id) {
        Post post = postRepository.findById(id).orElseThrow(() -> new ResourceNotFoundException("post", "id", id));

        return mapToDTO(post);
    }

    @Override
    public PostDto updatePost(PostDto postDto, long id) {
        Post post = postRepository.findById(id).orElseThrow(() -> new ResourceNotFoundException("post", "id", id));
        post.setTitle(postDto.getTitle());
        post.setDescription(postDto.getDescription());
        post.setContent(postDto.getContent());

        Post updatePost = postRepository.save(post);
        return mapToDTO(updatePost);
    }

    @Override
    public void deletePostById(long id) {
        Post post = postRepository.findById(id).orElseThrow(() -> new ResourceNotFoundException("post", "id", id));
        postRepository.delete(post);
    }


    @Override
    public PostResponse getAllPost(int pageNo, int pageSize, String sortBy, String sortDir) {

        Sort sort = sortDir.equalsIgnoreCase(Sort.Direction.ASC.name()) ? Sort.by(sortBy).ascending()
                : Sort.by(sortBy).descending();

        // create pageable instance
        PageRequest pageRequest = PageRequest.of(pageNo, pageSize, sort);
        Page<Post> pagePosts = postRepository.findAll(pageRequest);

        // get content for page abject
        List<Post> posts = pagePosts.getContent();
        List<PostDto> postDtos = posts.stream().map(post -> mapToDTO(post)).collect(Collectors.toList());;

        PostResponse postResponse = new PostResponse();
        postResponse.setContent(postDtos);
        postResponse.setPageNo(pagePosts.getNumber());
        postResponse.setPageSize(pagePosts.getSize());
        postResponse.setTotalElements(pagePosts.getTotalElements());
        postResponse.setTotalPages(pagePosts.getTotalPages());
        postResponse.setLast(pagePosts.isLast());
        return postResponse;
    }


    private PostDto mapToDTO(Post post) {
        PostDto postDto = new PostDto();
        postDto.setId(post.getId());
        postDto.setTitle(post.getTitle());
        postDto.setDescription(post.getDescription());
        postDto.setContent(post.getContent());

        return postDto;
    }

    private Post mapToEntity(PostDto postDto){
        Post post = new Post();
        post.setTitle(postDto.getTitle());
        post.setDescription(postDto.getDescription());
        post.setContent(postDto.getContent());

        return post;
    }
}

controller​

package com.chuwa.iccblog.controller;

@RestController
@RequestMapping("/api/v1/posts")
public class PostController {

    @Autowired
    private PostService postService;

    @PostMapping
    public ResponseEntity<PostDto> createPost(@RequestBody PostDto postDto) {
        // 调用 service
        PostDto postResponse = postService.createPost(postDto);
        return new ResponseEntity<>(postResponse, HttpStatus.CREATED);
    }


    @GetMapping("/{id}")
    public ResponseEntity<PostDto> getPostById(@PathVariable(name = "id") long id) {
        return ResponseEntity.ok(postService.getPostById(id));
    }

    @PutMapping("/{id}")
    public ResponseEntity<PostDto> updatePostById(@RequestBody PostDto postDto, @PathVariable(name = "id") long id) {
        PostDto postResponse = postService.updatePost(postDto, id);
        return new ResponseEntity<>(postResponse, HttpStatus.OK);
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<String> deletePost(@PathVariable(name = "id") long id) {
        postService.deletePostById(id);
        return new ResponseEntity<>("Post entity deleted successfully.", HttpStatus.OK);
    }

    /**
     * 该方法用于分页查询
     * @param pageNo
     * @param pageSize
     * @param sortBy
     * @param sortDir
     * @return PostResponse
     */
    @GetMapping
    public PostResponse getAllPosts(
            @RequestParam(value = "pageNo", defaultValue = AppConstants.DEFAULT_PAGE_NUMBER, required = false) int pageNo,
            @RequestParam(value = "pageSize", defaultValue = AppConstants.DEFAULT_PAGE_SIZE, required = false) int pageSize,
            @RequestParam(value = "sortBy", defaultValue = AppConstants.DEFAULT_SORT_BY, required = false) String sortBy,
            @RequestParam(value = "sortDir", defaultValue = AppConstants.DEFAULT_SORT_DIR, required = false) String sortDir
    ) {
        return postService.getAllPost(pageNo, pageSize, sortBy, sortDir);
    }
}

API Testing​

  • 通过 JWT 登录
  • 获取 accessToken

  • Authorization: Bearer Token
  • 填入 Token
  • 分页查询 or 全部查询