SpringBoot学习笔记09——spring-data-jpa初探

大家对JPA的褒贬不一，如果想弄清楚JPA是什么、值不值得用大家可以自行百度，博主这里就不再多说，因为说可能也说不明白，所以话不多说直接讲干货！

1.引入依赖

下边是整个dao曾模块的pom文件，世界上JPA的以来只有一个，已经添加了注释

<?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>com.example</groupId>
    <artifactId>world-address-dao</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>world-address-dao</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <artifactId>world</artifactId>
        <groupId>com.youyou</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </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>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!--这里是JPA的依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>${spring.boot.version}</version>
        </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

#配置数据源
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#配置数据源
spring.datasource.url=jdbc:mysql://192.168.31.199:3306/world?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root

#配置自动建表：updata:没有表新建，有表更新操作,控制台显示建表语句
spring.jpa.hibernate.ddl-auto=update
#显示执行的sql
spring.jpa.show-sql=true
#显示参数
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=trace

3.定义数据表实体

这里需要注意的是@Table注解中的参数是数据表的名字。

package com.youyou.address.entity;


import lombok.Data;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

/**
 * 数据库实体，联系人
 */
@Data
@Entity
@Table(name = "ts_contacter")
public class ContacterEO {
    /**
     * 主键
     */
    @Id
    private String id;
    /**
     * 姓名
     */
    private String name;

    /**
     * 性别（0，女；1，男）
     */
    private String sex;

    /**
     * 年龄
     */
    private Integer age ;

    /**
     * 电话
     */
    private  String phone;

    /**
     * 地址
     */
    private String location;

    /**
     * 删除（0，未删除；1，删除）
     */
    private String dflag ;
}

4.继承JpaRepository接口

继承JpaRepository接口之后会继承过来一系列的增删改查的方法

package com.youyou.address.dao;


import com.youyou.address.entity.ContacterEO;
import org.springframework.data.jpa.repository.JpaRepository;

public interface ContacterEORepo extends JpaRepository<ContacterEO , String> {
}

5.编写service类

这里只写了一个新增的方法用来测试。

package com.youyou.address.service;

import com.youyou.address.dao.ContacterDao;
import com.youyou.address.dao.ContacterEORepo;
import com.youyou.address.entity.ContacterEO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@Transactional
public class ContacterService {

    @Autowired
    private ContacterEORepo contacterEORepo;

    /**
     * 保存联系人
     * @param contacterEO
     */
    public void saveOne(ContacterEO contacterEO){
        contacterEORepo.save(contacterEO);
    }

}

6.controller层

package com.youyou.address.controller;


import com.youyou.address.entity.ContacterEO;
import com.youyou.address.service.ContacterService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@Api(description = "联系人接口")
@RestController
@RequestMapping(value = "/contacter")
public class ContacterController {

    @Autowired
    private ContacterService service;

    @ApiOperation(value = "新增")
    @GetMapping("/add")
    public ContacterEO  add(ContacterEO contacterEO){
        System.out.println("添加一个联系人");

        service.saveOne(contacterEO);

        return contacterEO;
    }

    

}

触探spring-data-jpa到此结束。