Spring整合MyBatis

整合步骤

一、导入相关jar包

（1）junit

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>

　　　　

（2) mybatis

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.2</version>
</dependency>

　　　　

（3）mysql-connector-java

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.19</version>
</dependency>

　　　　

（4）spring相关

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.1.10.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.1.10.RELEASE</version>
</dependency>

（5）AspectJ AOP 织入器

<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.4</version>
</dependency>

（6）mybatis-spring整合包 【重点】

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.2</version>
</dependency>

（7）配置Maven静态资源过滤问题！

<build>
    <resources>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
    </resources>
</build>

二、编写配置文件，代码实现

回忆MyBatis

1、创建实体类

package com.jia.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private Integer id;         //编号
    private String username;    //用户名
    private String password;    //密码
}

实现mybatis全局配置文件（也是核心配置文件）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!--配置别名-->
    <typeAliases>
        <package name="com.jia.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>

    <!--注册SQL映射文件-->
    <mappers>
        <mapper class="com.jia.mapper.UserMapper"/>
    </mappers>
</configuration>

UserMapper接口编写

package com.jia.mapper;


import com.jia.pojo.User;

import java.util.List;

public interface UserMapper {

    /**
     * 查询所有用户
     * @return
     */
    public List<User> selectUser();

    /**
     * 根据id查询用户
     * @param id
     * @return
     */
    public User selectUserById(Integer id);
    
}

接口对应的Mapper映射文件

<?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">

<!--绑定接口-->
<mapper namespace="com.jia.mapper.UserMapper">

    <select id="selectUser" resultType="User">
        SELECT * FROM User
    </select>

    <select id="selectUserById" resultType="User" parameterType="int">
        SELECT * FROM User WHERE id=#{id}
    </select>
</mapper>

测试类

import com.jia.mapper.UserMapper;
import com.jia.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MyTestMybatis {

    @Test
    //查询所有用户
    public void selectUser() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream input = Resources.getResourceAsStream(resource);
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(input);
        SqlSession sqlSession = sessionFactory.openSession(true);   //ture:自动提交事务

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.selectUser();
        for (User user : userList) {
            System.out.println(user);
        }
        //释放资源
        sqlSession.close();
    }

    @Test
    //根据id查询用户
    public void selectUserById() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream input = Resources.getResourceAsStream(resource);
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(input);
        SqlSession sqlSession = sessionFactory.openSession(true);

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = mapper.selectUserById(2);
        System.out.println(user);

        sqlSession.close();
    }
}

MyBatis-Spring学习

　　　　引入Spring之前需要了解mybatis-spring包中的一些重要类

　　　　官方文档：http://www.mybatis.org/spring/zh/index.html

什么是 MyBatis-Spring？

　　　　MyBatis-Spring 会帮助你将 MyBatis 代码无缝地整合到 Spring 中

 知识基础

　　　　在开始使用 MyBatis-Spring 之前，你需要先熟悉 Spring 和 MyBatis 这两个框架和有关它们的术语。这很重要

MyBatis-Spring 需要以下版本：

　　　　如果使用 Maven 作为构建工具，仅需要在 pom.xml 中加入以下代码即可：

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.2</version>
</dependency>

整合实现

1、引入Spring配置文件beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

2、配置数据源替换mybaits的数据源

<!--配置数据源：数据源有非常多，可以使用第三方的，也可使使用Spring的-->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf8"/>
    <property name="username" value="root"/>
    <property name="password" value="123456"/>
</bean>

3、配置SqlSessionFactory，关联MyBatis

<!--配置SqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <!--关联Mybatis-->
    <property name="configLocation" value="classpath:mybatis-config.xml"/>
    <property name="mapperLocations" value="classpath:com/kuang/dao/*.xml"/>
</bean>

4.注册sqlSessionTemplate，关联sqlSessionFactory；

<!--注册sqlSessionTemplate , 关联sqlSessionFactory-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
    <!--利用构造器注入,源码里没有set方法-->
    <constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

5、增加Dao接口的实现类，私有化sqlSessionTemplate

package com.jia.mapper;

import com.jia.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;
import java.util.List;

public class UserMapperImpl implements UserMapper{

    //sqlSession不用我们自己创建了，Spring来管理
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

    public List<User> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }

    public User selectUserById(Integer id) {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUserById(2);
    }
}

6、注册bean实现

    <!--注册UserMapperImpl-->
    <bean id="userMapper" class="com.jia.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

7、测试

import com.jia.mapper.UserMapper;
import com.jia.pojo.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

public class MyTestMybatis {

    @Test
    //查询所有用户
    public void selectUser() throws IOException {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }
    }

    @Test
    //根据id查询用户
    public void selectUserById() throws IOException {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
        User userById = userMapper.selectUserById(1);
        System.out.println(userById);
    }
}

结果成功输出！现在我们的Mybatis配置文件的状态！发现都可以被Spring整合！

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!--配置别名-->
    <typeAliases>
        <package name="com.jia.pojo"/>
    </typeAliases>

</configuration>