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。