6_5.springboot2.x数据整合springData JPA

清疚 2023-06-03 09:59 120阅读 0赞

### 1、配置文件 ###

**pom.xml**

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jdbc</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
        </dependencies>

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2phdHBlbg_size_16_color_FFFFFF_t_70][]

**2、application.yml**

spring:
      datasource:
        url: jdbc:mysql://localhost:3306/jpa?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone = GMT
        username: root
        password: 123456
        driver-class-name: com.mysql.cj.jdbc.Driver
      jpa:
        hibernate:
          # 更新或者创建数据表
          ddl-auto: update
          # 展示sql
        show-sql: true
    
      main:
        allow-bean-definition-overriding: true

**3、新建pojo**

**使用JPAz注解配置映射关系**

package com.spoot.springboot.pojo;
    
    import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
    
    import javax.persistence.*;
    
    //使用JPAz注解配置映射关系
    //@Entity告诉JPA这是一个实体类和数据表映射的类 @Table指定和哪个表对应；如果省略表明就是user
    @Entity
    @Table(name = "tb_user")
    @JsonIgnoreProperties(value = { "hibernateLazyInitializer", "handler" })
    public class User {
        //这是一个主键.同时标注这是一个自增主键
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Integer id;
        @Column(name = "last_name",length = 255)
        private String lastName;
        @Column
        private String email;
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public String getLastName() {
            return lastName;
        }
    
        public void setLastName(String lastName) {
            this.lastName = lastName;
        }
    
        public String getEmail() {
            return email;
        }
    
        public void setEmail(String email) {
            this.email = email;
        }
    }

@JsonIgnoreProperties(value = \{ "hibernateLazyInitializer", "handler" \})

fasterxml.jackson将对象转换为json

**4、编写repository接口**

package com.spoot.springboot.repository;
    
    import com.spoot.springboot.pojo.User;
    import org.springframework.data.jpa.repository.JpaRepository;
    
    //继承JpaRepository完成数据的操作 JpaRepository<User,Integer> 泛型操作的类和主键
    public interface UserRepository extends JpaRepository<User,Integer> {
    
    
    
    }

继承JpaRepository完成数据的操作 JpaRepository<User,Integer> 泛型操作的类和主键

**5、controller**

package com.spoot.springboot.controller;
    
    import com.spoot.springboot.pojo.User;
    import com.spoot.springboot.repository.UserRepository;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.Optional;
    
    @RestController
    public class UserController {
    
        @Autowired
        UserRepository userRepository;
    
        @RequestMapping("/user/{id}")
        public User getUset(@PathVariable("id") Integer id){
            User user = userRepository.getOne(id);
            return user;
        }
    
        @GetMapping("/user")
        public User getUset(User user){
            User save = userRepository.save(user);
            return save;
        }
    }

在yml中配置 ddl-auto: update会自动更新和创建表

测试：

![2019100613173186.png][]

OK！

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2phdHBlbg_size_16_color_FFFFFF_t_70]: /images/20230601/03b45cd310b54172a7017656db40c3ed.png
[2019100613173186.png]: /images/20230601/6c5ec896a0d64261b3d2cfeb0390fabe.png