SpringBoot 与 JPA

实现数据的增删改查

1.导入依赖

<!--  引入mysql需要的依赖  -->
    <dependency>  
            <groupId>mysql</groupId>  
            <artifactId>mysql-connector-java</artifactId>  
   </dependency>  
    <!--  引入spring data jpa需要的依赖  -->
    <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-data-jpa</artifactId>  
   </dependency>

2. 创建src/main/resource下的application.yml文件

##数据库四大连接参数
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql:///springbootjpa
    username: root
    password: 123
##jpa表的生成策略
  jpa:
    hibernate:
      ddl-auto: update

3.创建Grade实体类

@Entity
public class Grade {
    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private Integer grade_id;
    private String grade_name;

    public Integer getGrade_id() {
        return grade_id;
    }

    public void setGrade_id(Integer grade_id) {
        this.grade_id = grade_id;
    }

    public String getGrade_name() {
        return grade_name;
    }

    public void setGrade_name(String grade_name) {
        this.grade_name = grade_name;
    }
}

4. 创建dao层

/**
 * CrudRepository<实体，主键数据类型>
 */
@Repository
public interface IGradeMapper extends CrudRepository<Grade,Integer> {
}

5. 创建service层接口

public interface IGradeService {
    public Grade insertGrade(Grade grade);


    public Grade updateGrade(Grade grade);

    public void deleteGrade(Integer id);


    public Iterable<Grade> getAll();
}

6.创建service实现类

@Service("iGradeService")
public class IGradeServcieImpl implements IGradeService {
    @Resource
    private IGradeMapper iGradeMapper;


    @Override
    public Grade insertGrade(Grade grade) {
        return iGradeMapper.save(grade);
    }

    @Override
    public Grade updateGrade(Grade grade) {
        return iGradeMapper.save(grade);
    }

    @Override
    public void deleteGrade(Integer id) {
        iGradeMapper.delete(id);

    }

    @Override
    public Iterable<Grade> getAll() {
        return iGradeMapper.findAll();
    }

}

7. 创建controller层

@RestController
@RequestMapping("/IGradeController")
public class IGradeController {
    @Resource
    private IGradeService iGradeService;

    //新增数据
    @RequestMapping("/insertGrade")
    public Grade insertGrade(){
        Grade grade=new Grade();
        grade.setGrade_name("S1");
        return iGradeService.insertGrade(grade);
    }

    @RequestMapping("/updateGrade")
    public Grade updateGrade(){
        Grade grade=new Grade();
        grade.setGrade_id(1);
        grade.setGrade_name("S2");
        return iGradeService.updateGrade(grade);
    }

    @RequestMapping("/deleteGrade")
    public void deleteGrade(){

        iGradeService.deleteGrade(1);
    }

    @RequestMapping("/getAllGrade")
    public Iterable<Grade> getAllGrade(){
       return  iGradeService.getAll();
    }
}

8.创建StartSpringBoot测试类

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

9.浏览器测试

(1.)基本理论

JPA是Java Persistence API的简称，中文名Java持久层API，是JDK 5.0注解或XML描述对象－关系表的映射关系，并将运行期的实体对象持久化到数据库中。

(1.)基本理论

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