在我们平时使用spring-mybatis开发程序时,数据库的操作是必不可少的,DAO层在开发程序时也是经常需要编写的,在使用mybatis编写DAO层是有两种方式,一种是传统的DAO编写,还有一种就是动态代理。
1.传统的DAO模型编写
我们需要一个dao,这里是一个组织用户的dao接口
public interface AssociationUserDao {
boolean createUser (AssociationUser associationUser) throws Exception;
boolean removeUser(String username) throws Exception;
boolean updateUser(AssociationUser associationUser) throws Exception;
AssociationUser findOneByUsername(String username) throws Exception;
List<AssociationUser> findManyAssociationUser(int limit) throws Exception;
List<AssociationUser> findAllUser() throws Exception;
UserInfo getUserInfo(String username) throws Exception;
}
传统的dao模型编写还需要实现这个dao,这里只是展示了实现dao的一个方法。
public class UserDaoImpl extends SqlSessionDaoSupport implements AssociationUserDao {
@Override
public AssociationUser findOneByUsername(String username) throws Exception {
SqlSession sqlSession = getSqlSession();
AssociationUser user = sqlSession.selectOne("com.fancy.dao.AssociationUserDao", username);
sqlSession.commit();
return user;
}
mapper.xml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">
<mapper namespace="com.fancy.dao.AssociationUserDao">
<insert id="createUser" parameterType="com.fancy.model.AssociationUser" >
INSERT into associationuser VALUES ( #{username} , #{password} , #{email} , #{ID} , #{phone}
, #{friends} , #{iconLocation} , #{mode}) ;
</insert>
<select id="findOneByUsername" parameterType="String" resultType="com.fancy.model.AssociationUser">
SELECT * from associationuser where username = #{username} ;
</select>
<update id="updateUser" parameterType="com.fancy.model.AssociationUser" >
UPDATE associationuser set username = #{username} , password = #{password} , email = #{email} , ID = #{ID} ,
phone = #{phone} , friends = #{friends} , iconLocation = #{iconLocation} , mode = #{mode} WHERE username = #{username} ;
</update>
<delete id="removeUser" parameterType="String" >
delete from associationuser WHERE username = #{username} ;
</delete>
<select id="findAllUser" resultType="com.fancy.model.AssociationUser">
SELECT * from associationuser;
</select>
<select id="getUserInfo" parameterType="String" >
</select>
</mapper>
与spring整合的applicationContext<?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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"
>
<bean class="com.fancy.configue.BeanConfig"/>
<context:component-scan base-package="com.fancy.dao.impl" />
<context:component-scan base-package="com.fancy.service" />
<tx:annotation-driven proxy-target-class="false" transaction-manager="appTransactionManager" />
<bean id="dataSource" class="org.apache.ibatis.datasource.pooled.PooledDataSource">
<property name="url" value="jdbc:mysql://localhost:3306/Association" />
<property name="username" value="root" />
<property name="password" value="123" />
<property name="driver" value="com.mysql.jdbc.Driver" />
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
//mapper文件路径
<property name="mapperLocations" value="classpath:com/fancy/mapper/*.xml"/>
</bean>
<bean id="appTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate" >
<constructor-arg ref="sqlSessionFactory"/>
</bean><bean id="userDaoImpl" class="com.fancy.dao.impl.UserDaoImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
<bean id="userDaoImpl" class="com.fancy.dao.impl.UserDaoImpl"> <property name="sqlSessionFactory" ref="sqlSessionFactory"></property> </bean></beans>
2.使用Mapper代理
在使用mapper代理的时候只需要给出dao接口就行,不需要给出实现类,dao和mapper.xml,都不变,但是spring的ApplicationContext的xml文件需要改变一下
由原来的
<bean id="userDaoImpl" class="com.fancy.dao.impl.UserDaoImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
改成
<bean id="userDaoImpl" class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="mapperInterface" value="com.fancy.dao.AssociationUserDao"></property>
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
由MapperFactoryBean动态代理。