Mybatis基础系列（三）

古城微笑少年丶 2021-09-27 01:30 377阅读 0赞

# 一、整合思路 #

**1、SqlSessionFactory对象应该放到spring容器中作为单例存在。  
2、传统dao的开发方式中，应该从Spring容器中获得SqlSession对象。  
3、Mapper代理形式中，应该从Spring容器中直接获得mapper的代理对象。  
4、数据库的连接以及数据库连接池事务管理都交给spring容器来完成。**

# 二、整合步骤 #

**Spring配置文件：**

<context:property-placeholder location="classpath:db.properties"/>
    
    
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="maxActive" value="10" />
        <property name="maxIdle" value="5" />
    </bean>
    
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        
        <property name="configLocation" value="classpath:sqlMapConfig.xml"/>
    </bean>
    
    
    <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
        <property name="mapperInterface" value="com.long.mapper.UserMapper"/>
    </bean>
    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        
        <property name="basePackage" value="com.long.mybatis.mapper"/>
    </bean>

**UserMapper接口：**

public interface UserMapper {
        public User findUserById(Integer id);
    }

**UserMapper.xml：**

<mapper namespace="com.long.mapper.UserMapper">
        
        <select id="findUserById" parameterType="Integer" resultType="User">
            select * from user where id = #{v}
        </select>
    </mapper>

**sqlmapConfig.xml：**

<?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>
        
        <typeAliases>
            
            <package name="com.long.mybatis.pojo" />
        </typeAliases>
        <mappers>
            <package name="com.long.mybatis.mapper"/>
        </mappers>
    
    </configuration>

**测试：**

public class JunitTest {
        @Test
        public void testMapper() throws Exception {
            ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
            UserMapper mapper = ac.getBean(UserMapper.class);
    // UserMapper mapper = (UserMapper) ac.getBean("userMapper");
            User user = mapper.findUserById(10);
            System.out.println(user);
        }
    }

> **转载请标明出处，原文地址：[https://blog.csdn.net/weixin\_41835916][https_blog.csdn.net_weixin_41835916]  
> 总结整理不容易，如果觉得本文对您有帮助，请点击顶支持一下，您的支持是我写作最大的动力，谢谢。  
> ![这里写图片描述][70]**

[https_blog.csdn.net_weixin_41835916]: https://blog.csdn.net/weixin_41835916
[70]: /images/20210923/b94fa15a1f3a4a30bb09998b21d2f87b.png