spring boot 实现怎删改查

在Spring Boot中实现简单的CRUD（创建、读取、更新、删除）操作，你可以使用Spring Data JPA。以下是一个简单的例子：

1. 添加依赖到你的pom.xml：

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
</dependencies>

2. 创建一个实体类（Entity）：

import javax.persistence.*;
 
@Entity
public class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
 
    private String name;
 
    // 省略getter和setter方法
}

3. 创建一个继承JpaRepository的接口：

import org.springframework.data.jpa.repository.JpaRepository;
 
public interface MyEntityRepository extends JpaRepository<MyEntity, Long> {
}

4. 创建一个服务类（Service）：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.util.List;
 
@Service
public class MyEntityService {
    @Autowired
    private MyEntityRepository repository;
 
    public List<MyEntity> findAll() {
        return repository.findAll();
    }
 
    public MyEntity save(MyEntity entity) {
        return repository.save(entity);
    }
 
    public MyEntity findById(Long id) {
        return repository.findById(id).orElse(null);
    }
 
    public void deleteById(Long id) {
        repository.deleteById(id);
    }
 
    public MyEntity update(MyEntity entity) {
        return repository.save(entity);
    }
}

5. 创建一个控制器类（Controller）：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
 
import java.util.List;
 
@RestController
@RequestMapping("/api/myentities")
public class MyEntityController {
    @Autowired
    private MyEntityService service;
 
    @GetMapping
    public List<MyEntity> getAll() {
        return service.findAll();
    }
 
    @PostMapping
    public MyEntity create(@RequestBody MyEntity entity) {
        return service.save(entity);
    }
 
    @GetMap