[Java知识库]整合Mybatis-Spring（一）

经过这两周的学习，把Mybatis与Spring过了一遍，简单的分享下两种整合Mybatis-Spring方式。

第一种实现整合方式：

先看结构：

在xml中，导入相对应的插件，如下：

<dependencies>
        <!--mybatis-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
        </dependency>
        <!--连接数据库-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <!--使用mybatis框架-->
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.4</version>
        </dependency>
        <!-- 直接导入spring-webmvc会自动帮我们导入spring-aop，spring-beans，
                spring-context，spring-core，spring-expression，spring-web的依赖jar包 -->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.16</version>
        </dependency>
        <!-- 配置声明式事务 -->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.17</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.9</version>
        </dependency>
        <!-- spring-mybatis -->
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring Spring整合Mybatis需要的整合包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.7</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
    </dependencies>
	<!--防止出现导出资源失败-->
    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

先建pojo包下的User（实体类）:

package com.jin.pojo;

import lombok.Data;
@Data
public class User {
    /*id,name,pwd都是要与数据库中的字段相同*/
    private int id;
    private String name;
    private String pwd;

}

UserMapper（接口）:

注意：（选择interface，而不是class）

package com.jin.mapper;
import com.jin.pojo.User;
import java.util.List;

public interface UserMapper {
    public List<User> selectUser();
}

UserMapper.xml:

<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
        
<!--namespace：意思是“命名空间”，后面跟接口的路径。-->
<mapper namespace="com.jin.mapper.UserMapper">
    <select id="selectUser" resultType="com.jin.pojo.User">
        select * from mybatis01.users
    </select>
</mapper>

UserMapperImpl：

package com.jin.mapper;

import com.jin.pojo.User;
import lombok.Data;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;
@Data
public class UserMapperImpl implements UserMapper{

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

再建resources资源文件包下的spring-dao.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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd">
        
<!--value中:写入自己的连接mysql信息-->
<!--使用Spring的数据源替换Mybatis的配置-->
<!--class中报红，看一下是不是没导入spring-jdbc插件，记得刷新Maven-->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/mybatis01?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
    <property name="username" value="root"/>
    <property name="password" value="123456"/>
</bean>

    <!--创建工厂bean-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--绑定Mybatis配置文件-->
        <property name="mapperLocations" value="classpath:com/jin/mapper/*.xml"/>
    </bean>
    
   		<!--使用SqlSessionFactory创建SqlSessionTemplate-->
        <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
            <constructor-arg index="0" ref="sqlSessionFactory" />
        </bean>
        
	<!--注入SqlSessionTemplate-->
    <bean id="userMapper" class="com.jin.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

</beans>

最后建个用来测试的 MyTest：

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

import java.io.IOException;

public class MyTest {
    @Test
    public void test() throws IOException{
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        UserMapper userMapper = (UserMapper) context.getBean("userMapper");
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }
    }
}

这样就可查询到mysql中的数据了，结果显示如下：

快速入口 ： 整合Mybatis-Spring（二）

可以对比一下，这两种整合方式都有什么不同！