1.引入依赖

<?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>2.0.7.RELEASE</version>
        <relativePath/>
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
    	<!-- SpringDataJPA依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
      	<!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        
 		<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

2.配置文件application.properties

# 数据源DataSource
spring.datasource.url=jdbc:mysql://8.129.176.154:3307/addressbook?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root

#SpringDataJPA的配置
#创建数据库的方式类型 update:当实体类有属性变动时，表就会跟着更新
spring.jpa.hibernate.ddl-auto=update
#显示对应操作的sql语句
spring.jpa.show-sql=true

3.创建实体类

@Entity //指明此类是与数据库表对应的实体类
@Table(name = "t_user") //指名 此类对应的表名
public class User {

    @Id //指明此属性 是主键
    @GeneratedValue(strategy = GenerationType.IDENTITY) //主键自增，也即：数据表的主键自增
    private Integer id;

	@Column(name = "name")
    private String name;

    private String number;

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getNumber() {
        return number;
    }

    public void setNumber(String number) {
        this.number = number;
    }
}

注：若实体类中属性名与数据库中字段名不同，需要用  @Column(name="t_name")指明映射关系

4.SpringBoot JPA提供的核心接口
 
 1、Repository接口
 2、CrudRepository接口
 3、PagingAndSortingRepository接口
 4、JpaRepository接口
 5、JPASpecificationExecutor接口
 

5.主要学习JpaRepository接口，创建持久化接口，简化操作持久层的代码，只需要编写接口就可以

注：创建一个接口，继承接口 JpaRepository<类名，类的主键属性的类型>

public interface UserRepository extends JpaRepository<User,Integer> {
}

 

6.发送请求测试

@RestController
public class UserController {

    @Autowired
    private UserRepository userRepository;


    @RequestMapping("/hello")
    public Object hello(){
        return "hello";
    }

    @RequestMapping("/save")
    public void save(){
        User user = new User();
        user.setName("xiaomeimei");
        user.setNumber("15999999999");
        userRepository.save(user);
    }

    @RequestMapping("/find")
    public Object find(){
        return userRepository.findAll();
    }
}