Spring Boot 整合 Spring Data JPA

1. 依赖导入

<?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>2.6.6</version>
        <relativePath/>
    </parent>
    <groupId>com.liu</groupId>
    <artifactId>springboot_day4</artifactId>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

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

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

2. User实体类

@Data
@Entity(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Column
    private String name;
    @Column
    private String phone;
    @Column
    private String pwd;
}

3. 创建 UserDAO 接口

package com.liu.dao;

import com.liu.entity.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
//传入两个泛型，第一个是操作映射的实体类型，第二个是主键字段的类型
public interface UserDAO extends JpaRepository<User,Long> {
}

4. 创建controller，注入 UserDAO

package com.liu.controller;


import com.liu.dao.UserDAO;
import com.liu.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("user")
public class UserController {

    @Autowired
    private UserDAO userDAO;

    @GetMapping("/findAll")
    public List<User> findAll() {
        return userDAO.findAll();
    }

    @GetMapping("/findById/{id}")
    public User findById(@PathVariable("id") Long id) {
        return userDAO.findById(id).get();
    }

    @PostMapping("/save")
    public User save(@RequestBody User user) {
        return userDAO.save(user);
    }

    @PutMapping("/put")
    public User put(@RequestBody User user) {
        return userDAO.save(user);
    }

    @GetMapping("/deleteById/{id}")
    public void deleteById(@PathVariable("id") Long id) {
        userDAO.deleteById(id);
    }
}

5. application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/db08?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    name: root
    password: 8485
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    show-sql: true
    properties:
      hibernate:
        format_sql: true

6. Spring Boot 启动类

package com.liu;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootDay4Application {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootDay4Application.class, args);
    }

}

postman测试