一起来学SpringBoot（七）持久层框架

springboot具有非常棒的持久层框架支持，下面我将介绍我用过的三种持久层框架进行简述使用。

由于这里操作的都是一张表，这里贴出通用的yml和建表语句 切记这里使用的是mysql8 ，5.8之前的朋友请修改后缀去掉com.mysql.cj.jdbc.Driver 中的cj。

DROP TABLE IF EXISTS `Test`;
CREATE TABLE `Test`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '姓名',
  `age` int(11) NULL DEFAULT NULL COMMENT '年龄',
  `inhere` tinyint(4) NULL DEFAULT NULL COMMENT '在不在',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;

spring:
  datasource:
    url: jdbc:mysql://192.168.8.100:3306/FuLinTest?characterEncoding=utf8&useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver

---

JdbcTemplate

首先呢看下项目结构

记得使用之前千万不要不加依赖哈哈

        <!-- jdbcTemplate -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

然后贴出实体类

package com.maoxs.pojo;

import lombok.Data;

import java.io.Serializable;

@Data
public class MyTest implements Serializable {
    private Long id;
    private String name;
    private int age;
    private Boolean inhere;

    public MyTest() {
    }

    public MyTest(String name, int age, Boolean inhere) {
        this.name = name;
        this.age = age;
        this.inhere = inhere;
    }

    public MyTest(Long id, String name, int age, Boolean inhere) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.inhere = inhere;
    }

    @Override
    public String toString() {
        final StringBuffer sb = new StringBuffer("MyTest{");
        sb.append("id=").append(id);
        sb.append(", name='").append(name).append('\'');
        sb.append(", age=").append(age);
        sb.append(", inhere=").append(inhere);
        sb.append('}');
        return sb.toString();
    }
}

然后是dao层的实现类和接口

package com.maoxs.dao;

import com.maoxs.pojo.MyTest;

public interface MyTestDao {

    MyTest selectOne(Long id);

    int insert(MyTest myTest);

    int delete(Long id);

    int update(MyTest myTest);
}

package com.maoxs.dao.impl;

import com.maoxs.dao.MyTestDao;
import com.maoxs.pojo.MyTest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class MyTestDaoImpl implements MyTestDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public MyTest selectOne(Long id) {
        String sql = "select id,name,age,inhere from Test where id=? ";
        return jdbcTemplate.queryForObject(sql, (resultSet, i) -> {
            MyTest myTest = new MyTest();
            myTest.setId(resultSet.getLong("id"));
            myTest.setName(resultSet.getString("name"));
            myTest.setAge(resultSet.getInt("age"));
            myTest.setInhere(resultSet.getBoolean("inhere"));
            return myTest;
        }, id);
    }

    @Override
    public int insert(MyTest myTest) {
        String sql = "insert into Test (name,age,inhere) values(?,?,?)";
        return jdbcTemplate.update(sql, myTest.getName(), myTest.getAge(), myTest.getInhere());
    }

    @Override
    public int delete(Long id) {
        String sql = "delete from Test where id=?";
        return jdbcTemplate.update(sql, id);
    }

    @Override
    public int update(MyTest myTest) {
        String sql = "update Test set name=?,age=?,inhere=? where id=?";
        return jdbcTemplate.update(sql, myTest.getName(), myTest.getAge(), myTest.getInhere(), myTest.getId());
    }
}

然后呢编写测试看看都能用不

package com.maoxs;

import com.maoxs.dao.MyTestDao;
import com.maoxs.pojo.MyTest;
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.Collections;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootJdbcApplicationTests {
    @Autowired
    private MyTestDao myTestDao;

    @Test
    public void insert() {
        MyTest myTest = new MyTest("fulin", 18, true);
        myTestDao.insert(myTest);
    }

    @Test
    public void selectOne() {
        System.out.println(myTestDao.selectOne(1L));
    }


    @Test
    public void update() {
        MyTest myTest = new MyTest(1L, "fulin", 18, true);
        myTestDao.update(myTest);
    }

    @Test
    public void delete() {
        myTestDao.delete(13L);
    }
}

ok 我这边测试都通过了

---

Spring Data jpa

首先呢还是先看下项目结构

然后使用的时候千万不要忘了加依赖

        <!-- jpa -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

先看下实体，不要写错注解

package com.maoxs.pojo;

import lombok.Data;

import javax.persistence.*;
import java.io.Serializable;

@Data
@Entity
@Table(name = "MyTest")
public class MyTest implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Column
    private String name;
    @Column
    private int age;
    @Column
    private Boolean inhere;
}

SpringBoot创建DAO层很多种方法其中japrepository是最强大的而且最有特色的一种，我们可以针对不同的实体创建repository接口。Spring会根据方法名称的规则进行自动生成实现，强大的不要不要的。在SpringBoot中默认已经提供了非常多的常规CRUD操作的repository，以下就是Spring为我们提供的repository接口

package com.maoxs.dao;

import com.maoxs.pojo.MyTest;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface TestDao extends JpaRepository<MyTest, Long> {
}

别看啥都没有功能超级牛逼 具体可以去jpa官网学习下怎么使用的 JPA 学习手册

在看下service

package com.maoxs.service;

import com.maoxs.pojo.MyTest;

import java.util.List;

public interface TestService {
    void add(MyTest tset) throws Exception;

    void update(MyTest myTest) throws Exception;

    void del(Long id) throws Exception;

    List<MyTest> select() throws Exception;
}

package com.maoxs.service.impl;

import com.maoxs.dao.TestDao;
import com.maoxs.pojo.MyTest;
import com.maoxs.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class TestServiceImpl implements TestService {
    @Autowired
    private TestDao testDao;


    @Override
    public void add(MyTest tset) throws Exception {
        testDao.save(tset);
    }

    @Override
    public void update(MyTest myTest) throws Exception {
        testDao.saveAndFlush(myTest);
    }

    @Override
    public void del(Long id) throws Exception{
        testDao.deleteById(id);
    }

    @Override
    public List<MyTest> select() throws Exception {
        return testDao.findAll();
    }
}

然后写个测试类测试下

package com.maoxs;

import com.maoxs.pojo.MyTest;
import com.maoxs.service.TestService;
import org.junit.Assert;
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.Collections;
import java.util.List;
import java.util.stream.Collectors;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootJpaApplicationTests {

    @Autowired
    private TestService testService;


    @Test
    public void add() throws Exception {
        MyTest t = new MyTest();
        t.setAge(11);
        t.setInhere(false);
        t.setName("DesrCat");
        testService.add(t);
    }

    @Test
    public void update() throws Exception {
        MyTest t = new MyTest();
        t.setAge(180);
        t.setInhere(false);
        t.setName("昴先生111");
        t.setId(1L);
        testService.update(t);
    }

    @Test
    public void select() throws Exception {
        List<MyTest> select = testService.select();
        Assert.assertTrue(select.size() > 0);
        System.out.println(Collections.unmodifiableCollection(select));
    }

    @Test
    public void del() throws Exception {
        testService.del(11L);
    }


}

我这里是都通过了你呢?

---

Mybatis

这里看下项目结构

依赖依赖依赖依赖

        <!--mybatis  -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>

这里的yml需要加入

mybatis:
  mapper-locations: classpath:/mapper/*.xml
  type-aliases-package: com.maoxs.pojo

然后呢是实体

package com.maoxs.pojo;

import lombok.Data;

import java.io.Serializable;

@Data
public class MyTest implements Serializable {
    private Long id;
    private String name;
    private int age;
    private Boolean inhere;

}

然后呢是dao

package com.maoxs.dao;

import com.maoxs.pojo.MyTest;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface MyTestMapper {
    List<MyTest> findAll();
}

mapper

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.maoxs.dao.MyTestMapper">
    <sql id="base_sql">
         a.id as  id,
         a.name as  name,
         a.age as  age,
         a.inHere as inHere
    </sql>
    <select id="findAll" resultType="com.maoxs.pojo.MyTest">
        select
        <include refid="base_sql"/>
        from
        Test a
    </select>
</mapper>

切记在启动类上加入MapperScan 注解

package com.maoxs;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.maoxs")
public class SpringbootMybatisApplication {

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

然后是测试类

package com.maoxs;

import com.maoxs.dao.MyTestMapper;
import com.maoxs.pojo.MyTest;
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.Collections;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootMybatisApplicationTests {

    @Autowired
    private MyTestMapper myTestMapper;

    @Test
    public void findAll() {
        List<MyTest> all = myTestMapper.findAll();
        System.out.println(Collections.unmodifiableCollection(all));
    }

}

mybatis就不多说了，应该经常用吧实在不会的小伙伴 点击 mybatis 学习手册

---

然后呢就推荐大家使用mybatis的一个开源插件myabtis-plus

//TODO 后期呢我会放上使用帖子

mybatis-plus 学习手册

本博文是基于springboot2.x 如果有什么不对的请在下方留言。

相关连接：

个人博客地址 : www.fulinlin.com

csdn博客地址：https://blog.csdn.net/qq_32867467

集合源码地址 : https://gitee.com/Maoxs/springboot-test

注：如果不对联系本宝宝及时改正~~