Spring入门学习（四、基于代理模式整合Mybatis）

实现步骤

• Spring中配置dataSource以及SessionFactory
• Spring中配置dao的代理类的bean
• 测试
• 可以看出和映射有很多代码是可以复用的
• 同时我们需要注意，代理类我们需要同名同包

代码结构

Spring配置文件

 <?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"
       xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.1.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
        http://www.springframework.org/schema/task
        http://www.springframework.org/schema/task/spring-task-3.1.xsd">
        
   <context:property-placeholder location="classpath:db.properties"/>
   
   <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
   		<property name="driverClassName" value="${driver}"></property>
   		<property name="password" value="${password}"></property>
   		<property name="url" value="${url}"></property>
   		<property name="username" value="${username}"></property>
   		<property name="maxActive" value="10"></property>
   		<property name="maxIdle" value="5"></property>
   </bean>
   
   <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
   		<property name="dataSource" ref="dataSource"></property>
   </bean>
  
   
    <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
   		<property name="mapperInterface" value="mapper.UserMapper"></property>
   		<property name="sqlSessionFactory" ref="sessionFactory"></property>
   </bean>
   
</beans>

• 这里的代码和映射代码相差不多，只是多了个代理类的配置
• <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">这胡娟就是配置的我们的代理类了
  • <property name="mapperInterface" value="mapper.UserMapper"></property>这里是映射的我们的接口类所在的位置
  • <property name="sqlSessionFactory" value="sessionFactory"></property>这里是映射的我们的sqlsessionfactory

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="mapper.UserMapper">		
	
	<select id="findById" parameterType="int" resultType="domain.User">
		select * from tb_user where id=#{id}
	</select>
	
</mapper>

public interface UserMapper {
	public User findById(int id);
}

测试类

public class Text {
	public static void main(String[] args) {
		
		ApplicationContext ac=new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
		UserMapper userMapper=(UserMapper) ac.getBean("userMapper");
		User user=userMapper.findById(1);
		System.out.println(user);
	}
}

总结

• 这个代码整体来说就比刚刚的简单的多了
• 更多的是靠接口和配置的代理bean完成
• 那么如果我们的mapper有点多，怎么办呢？

基于扫描包的配置

  <!--  <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
   		<property name="mapperInterface" value="mapper.UserMapper"></property>
   		<property name="sqlSessionFactory" ref="sessionFactory"></property>
   </bean> -->
   
   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
   		<property name="basePackage" value="mapper"></property>
   		<property name="sqlSessionFactoryBeanName" value="sessionFactory"></property>
   </bean>

• 这里还是很简单的，就是吧前面的注释点，然后加上<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
• 测试类不用更改