0003SpringBoot整合SpringDataJPA

SpringBoot整合SpringDataJpa步骤如下：

1、添加data-jpa起步依赖（pom.xml）

2、添加数据库驱动坐标、添加Junit起步依赖(pom.xml)

3、添加数据库连接信息(application.properties)

4、创建user表，表已创建可省略

5、创建User对应的实体Bean(需要加注解的方式，而Mybatis不用任何注解)

6、创建UserReporitory接口，需要extends JpaRepository<User,Integer> (不再需要像Mybatis一样添加接口与查询语句对应的映射文件)

7、在application.properties中添加SpringDataJPA对应的关系

8、编写测试类

9、启动测试

具体内容如下：

pom.xml中的内容：

 <!--pringDataJPA-->
   <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <!--数据库驱动-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <!--不需要填写版本号，因为在父依赖里已经给了判断-->
        <!--<version>5.1.39</version>-->
    </dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

application.properties中的内容：

#数据库连接信息
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root@123
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#springboot整合springDataJPA信息
spring.jpa.hibernate.ddl-auto=update
# 控制台打印sql
spring.jpa.show-sql=true

User实体的内容：

package com.myself.domain;

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 int id;
    private String username;
    private String password;
    private String name;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", name='" + name + '\'' +
                '}';
    }
}

UserRepository.java接口的内容：

package com.myself.repository;

import com.myself.domain.User;
import org.springframework.data.jpa.repository.JpaRepository;
import java.util.List;

public interface UserRepository extends JpaRepository<User,Integer> {
    public List<User> findAll();
}

测试类的SpringDataJPATest.jva的内容：

package com.myself;

import com.myself.domain.User;
import com.myself.repository.UserRepository;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = SpringbootJpaApplication.class)
public class SpringDataJPATest {
    @Autowired
    private UserRepository userRepository;
    @Test
    public void queryUserTest(){
        List<User>  users = userRepository.findAll();
        System.out.println(users);

    }
}

项目结构图如下：

理解不到位之处望指教。