How to build a blog engine with React & Spring Boot – Part 2

+--------------------+
|   BlogController   |
+--------------------+
| - blogService: BlogService |
+--------------------+
| + addNewpost(post: Blogpost): BlogPost  |
| + getPost(): BlogPost |
| + getAllPosts(): List<BlogPost> |
| + getPostsByUsername(id: String): Void |
| + updatePost(id: Long, body: BlogPost): Void |
| + deletePost(id: Long): Void |
+--------------------+

         |
         |
         |
         *
+--------------------+
|   BlogService   |
+--------------------+
| - blogRepository: BlogRepository |
+--------------------+
| + createNewPost(blogPost: BlogPost): BlogPost |
| + getBlogPostBy(id: String): List<BlogPost>
| + findAll(): List<BlogPost> |
| + getPostsByUser(username: String): List<BlogPost> |
| + updatePost(id: Long, body: BlogPost): BlogPost |
| + deletePost(id: Long): Void |
+--------------------+

         |
         |
         |
         *
+--------------------+
|  BlogRepository extends JpaRespository<String, BlogPost>  |
+--------------------+
| + findAll(): List<BlogPost> |
| + save(book: Book): BlogPost |
| + deleteById(id: Long): void|
| + findById(id: Long): Optional<BlogPost> |
| + findPostsByUser(id: Long): List<BlogPost> |
+--------------------+

         |
         |
         |
         *
+--------------------+
|       Book         |
+--------------------+
| - id: Long         |
| - title: String    |
| - content: String   |
| - datePublished: String     |
| - username: String     |
+--------------------+
| + getters(): Object    |
| + setters(): Void |
+--------------------+

@RestController
@RequestMapping("/api/blog")
public class BlogController {

    private final BlogService blogService;

    public BlogController(BlogService blogService) {
        this.blogService = blogService;
    }
    @PostMapping("/post")
    @ResponseStatus(HttpStatus.CREATED)
    public BlogPost addNewPost(@RequestBody @Valid BlogPost post) {
        return blogService.createNewPost(post);
    }

    @GetMapping("/addMockPosts")
    public BlogPost createDummyPost() {
        BlogPost post = BlogPost.builder()
                .title("New Blog")
                .content("Lots of new content to keep coming and coming soon")
                .username("bhuman@mydaytodo.com")
                .build();
        return blogService.createNewPost(post);
    }
    @GetMapping("/post/{id}")
    @ResponseStatus(HttpStatus.OK)
    public BlogPost getBlogPost(@PathVariable("id") String id) {
        return blogService.getBlogPostBy(id); // to be completed later
    }

    @GetMapping("/post/")
    @ResponseStatus(HttpStatus.OK)
    public List<BlogPost> getAllPosts() {
        return blogService.findAll(); // to be completed later
    }

    @PatchMapping("/post/{id}")
    @ResponseStatus(HttpStatus.NO_CONTENT)
    public BlogPost updatePost(@PathVariable("id") String id, @RequestBody @Valid BlogPost post) {
        return blogService.updatePost(id, post);
    }
    @DeleteMapping("/post/{id}")
    @ResponseStatus(HttpStatus.NO_CONTENT)
    public void deletePost(@PathVariable("id") String id) {
        blogService.deletePost(id);
    }

    @GetMapping("/post/by/{username}")
    @ResponseStatus(HttpStatus.OK)
    public List<BlogPost> getPostsByUsername(@PathVariable("username") String username) {
        return blogService.getPostsByUser(username);
    }
}

@Service
@Slf4j
public class BlogService {

    @Autowired
    private BlogRepository blogRepository;

    public BlogService(BlogRepository blogRepository) {
        this.blogRepository = blogRepository;
    }
    public BlogPost createNewPost(BlogPost blogPost) {
        blogPost.setDatePublished(new Date());
        return blogRepository.save(blogPost);
    }

    public BlogPost getBlogPostBy(String id) {
        return blogRepository.findById(id).orElseThrow();
    }

    public List<BlogPost> findAll(){
        return blogRepository.findAll();
    }
    public List<BlogPost> getPostsByUser(String username) {
        return blogRepository.findPostsByUser(username);
    }

    public void deletePost(String id) {
        blogRepository.deleteById(id);
    }

    public BlogPost updatePost(String id, BlogPost body) {
        BlogPost post = blogRepository.findById(id).orElseThrow();
        if(body.getContent() != null) {
            post.setContent(body.getContent());
        }
        if(body.getTitle() != null) {
            post.setTitle(body.getTitle());
        }
        return blogRepository.save(post);
    }
}

@Repository
public interface BlogRepository extends JpaRepository<BlogPost, String> {
    @Query(value = "select * from blogpost where username = :username", nativeQuery = true)
    List<BlogPost> findPostsByUser(@Param("username") String username);
}

@SpringBootApplication
@ComponentScan({"com.mydaytodo.blog_backend.repository", "com.mydaytodo.blog_backend.controller", "com.mydaytodo.blog_backend.service"})
public class BlogBackendApplication {

	public static void main(String[] args) {
		SpringApplication.run(BlogBackendApplication.class, args);
	}
}

CREATE TABLE IF NOT EXISTS blogpost (id VARCHAR(9) PRIMARY KEY AUTO_INCREMENT, title VARCHAR(255), content VARCHAR(255)
, date_published DATE, username VARCHAR(255));

spring.application.name=blog-backend
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
spring.jpa.defer-datasource-initialization=true
spring.h2.console.enabled=true
spring.h2.console.path=/h2-console

spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto=update

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>3.3.4</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.mydaytodo</groupId>
	<artifactId>blog-backend</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>blog-backend</name>
	<description>Backend for blog engine</description>
	<url/>
	<licenses>
		<license/>
	</licenses>
	<developers>
		<developer/>
	</developers>
	<scm>
		<connection/>
		<developerConnection/>
		<tag/>
		<url/>
	</scm>
	<properties>
		<java.version>17</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>com.h2database</groupId>
			<artifactId>h2</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>


		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-validation</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.data</groupId>
			<artifactId>spring-data-r2dbc</artifactId>
		</dependency>

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>