springboot 整合 jpa，mysql

<dependencies>
    <!-- Spring Boot Starter Data JPA -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
 
    <!-- MySQL Connector -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
 
    <!-- Spring Boot Starter Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

spring.datasource.url=jdbc:mysql://localhost:3306/your_database_name?useSSL=false&serverTimezone=UTC
spring.datasource.username=your_username
spring.datasource.password=your_password
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
 
# JPA 配置
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
 
@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String email;
 
    // Getters and setters
    public Long getId() {
        return id;
    }
 
    public void setId(Long id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public String getEmail() {
        return email;
    }
 
    public void setEmail(String email) {
        this.email = email;
    }
}

import org.springframework.data.jpa.repository.JpaRepository;
 
public interface UserRepository extends JpaRepository<User, Long> {
    // 你可以在这里定义自定义的查询方法
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
 
@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;
 
    public List<User> getAllUsers() {
        return userRepository.findAll();
    }
 
    public User getUserById(Long id) {
        return userRepository.findById(id).orElse(null);
    }
 
    public User createUser(User user) {
        return userRepository.save(user);
    }
 
    public User updateUser(Long id, User userDetails) {
        User user = userRepository.findById(id).orElse(null);
        if (user != null) {
            user.setName(userDetails.getName());
            user.setEmail(userDetails.getEmail());
            return userRepository.save(user);
        }
        return null;
    }
 
    public void deleteUser(Long id) {
        userRepository.deleteById(id);
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
 
import java.util.List;
 
@RestController
@RequestMapping("/users")
public class UserController {
    @Autowired
    private UserService userService;
 
    @GetMapping
    public List<User> getAllUsers() {
        return userService.getAllUsers();
    }
 
    @GetMapping("/{id}")
    public ResponseEntity<User> getUserById(@PathVariable Long id) {
        User user = userService.getUserById(id);
        if (user != null) {
            return ResponseEntity.ok(user);
        } else {
            return ResponseEntity.notFound().build();
        }
    }
 
    @PostMapping
    public User createUser(@RequestBody User user) {
        return userService.createUser(user);
    }
 
    @PutMapping("/{id}")
    public ResponseEntity<User> updateUser(@PathVariable Long id, @RequestBody User userDetails) {
        User updatedUser = userService.updateUser(id, userDetails);
        if (updatedUser != null) {
            return ResponseEntity.ok(updatedUser);
        } else {
            return ResponseEntity.notFound().build();
        }
    }
 
    @DeleteMapping("/{id}")
    public ResponseEntity<Void> deleteUser(@PathVariable Long id) {
        userService.deleteUser(id);
        return ResponseEntity.noContent().build();
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }
}