springboot 2.1.x 整合 jpa

springboot 2.1.x 整合 jpa

思路 约定>配置>编码

记录一下了，方便以后复习；
版本：

java	1.8
spirngboot	v2.1.3.RELEASE
mysql	8.0.22
jpa	2.1.3.RELEASE

1.创键一个新的maven项目

下一步
2.配置 pom.xml 导入maven依赖

打开 pom.xml

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>springboot-jpa</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!-- JPA 依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>2.1.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.1.3.RELEASE</version>
        </dependency>

        <!-- 数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.16</version>
        </dependency>
    </dependencies>

</project>

3.创键springboot 启动类

TsetUserApplication.java

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

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

记得启动类TsetUserApplication一定要放到最外层

4.在resources文件夹下创键 application.yml

application.yml

#设置端口号
server:
  port: 8090

#数据源配置
spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://localhost:3306/shop?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root
    driverClassName: com.mysql.cj.jdbc.Driver

#jpa配置
  jpa:
      show-sql: true #控制台显示 sql语句
      hibernate:
        ddl-auto: update
      database-platform: org.hibernate.dialect.MySQL5InnoDBDialect

5.创键实体类 TestUser

不需要 创键表 jap 可以根据 实体类创键
@Table(name = “testUser”)
testUser ：表名

import lombok.Data;

import javax.persistence.*;


@Entity
@Data
@Table(name = "testUser")
public class TestUser {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    //id 主建自动增长 GenerationType.IDENTITY
    private Integer id;
    private String userName;
    private String password;
}

6.创建dao 层接口 TestUserDao

主意 JpaRepository<TestUser,Integer>

TestUser 实体类的名称
Integer 主建的数据类型

import com.zuoxing.entity.TestUser;
import org.springframework.data.jpa.repository.JpaRepository;

public interface TestUserDao extends JpaRepository<TestUser,Integer> {
}

7.创键controller 层 TestUserController

import com.zuoxing.dao.TestUserDao;
import com.zuoxing.entity.TestUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class TestUserController {

    @Autowired
    private TestUserDao dao;

    /**
     * 查询所有
     * @return
     */
    @GetMapping("")
    public List<TestUser> getAllTestUser(){
        return dao.findAll();
    }

    /**
     * 添加方法
     * @param testUser
     * @return
     */
    @PostMapping("/add")
    public TestUser addTestUser(TestUser testUser){
        return dao.save(testUser);
    }
}

8.输入地址 测试

http://localhost:8090/

没有也可以在浏览器上输入

注意是 post请求
如果浏览器不好测试的话 可以换成
@RequestMapping("/add")

下面放入项目路径图
这里简单测试一下就没有 写service层

创作不易，请标明出处
原著：一条努力的咸鱼