MyBatis之整合Spring

时间:2023-03-09 04:33:07
MyBatis之整合Spring

MyBatis之整合Spring

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

整合需要的jar包

  1、spring的jar包

  2、mybatis的jar包

  3、spring+mybatis的整合包

  4、mysql的数据库驱动jar包

  5、数据库连接池的jar包

MyBatis之整合Spring

配置sqlMapConfig.xml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>
<!-- 设置别名 -->
<typeAliases>
<!-- 2.指定扫描包,会把包内所有的类都设置别名,别名的名称就是类名,大小写不敏感 -->
<package name="deep.mybatis.pojo"/>
</typeAliases>
</configuration>

配置applicationContext.xml核心配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.2.xsd "> <!-- 加载配置文件 -->
<context:property-placeholder location="classpath:db.properties"/> <!-- dbcp 数据源 -->
<!-- 数据库连接池 -->
<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"/>
<!-- 最大空闲数量(最少留多少个连接) -->
<property name="maxIdle" value="5"/>
</bean> <!-- Mybatis的工厂 -->
<bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!-- 核心配置文件的位置 -->
<property name="configLocation" value="classpath:sqlMapConfig.xml"/>
</bean> </beans>

配置资源文件db.properties文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
jdbc.username=root
jdbc.password=123456

配置log4j.properties日志资源文件

#Global logging configuration
log4j.rootLogger=DEBUG,stdout
#Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p[%t]-%m%n

配置UserDaoImpl

<!-- Dao -->
<bean id="userDao" class="deep.mybatis.dao.UserDaoImpl">
<!-- 其实这个工厂并没有注入到UserDaoImp这个实现类里面,而是注入到了实现类的父类里去了 -->
<property name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
</bean>
package deep.mybatis.dao;

import org.mybatis.spring.support.SqlSessionDaoSupport;

/**
* 原始dao开发
* @author DeepSleeping
*
*/
public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao{ //声明工厂 public void insertUser(){
this.getSqlSession().insert("");
}
}

配置Mapper动态代理开发

applicationContext.xml

<!-- Mapper动态代理开发 -->
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<!-- 有工厂才能有session,有session才能有session.getMapper获得实现类 -->
<property name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
<property name="mapperInterface" value="deep.mybatis.mapper.UserMapper"/> </bean>
package deep.mybatis.mapper;

import deep.mybatis.pojo.User;

public interface UserMapper {

    public User findByUserId(Integer id);
}
<?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="deep.mybatis.mapper.UserMapper"> <!-- 通过ID查询一个用户 -->
<select id="findByUserId" parameterType="Integer" resultType="User">
select * from account where id = #{v}
</select>
</mapper>
package deep.mybatis.junit;

import static org.junit.Assert.*;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext; import deep.mybatis.mapper.UserMapper;
import deep.mybatis.pojo.User; public class JunitTest { @Test
public void testmapper() throws Exception {
ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
/*ac.getBean(UserMapper.class);*/
UserMapper userMapper = (UserMapper) ac.getBean("userMapper");
User user = userMapper.findByUserId(27);
System.out.println(user);
}
}

MyBatis之整合Spring

配置Mapper动态代理(增强版)

  上面的方式还是有弊端,给mybatis提供接口的时候,必须得指定到具体类。我们可以用mybatis中的另一个mapper包里的功能,扫描基本包下的所有

<!-- Mapper动态代理开发(增强版) 扫描 -->

     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 不需要指定工厂了,因为会自动去工厂中找到工厂bean -->
<!-- 配置基本包(扫描包下的所有的) -->
<property name="basePackage" value="deep.mybatis.mapper"></property>
</bean>