Spring与MyBatis整合上_Mapper动态代理方式

     将MyBatis与Spring进行整合，主要解决的问题就是将SqlSessionFactory对象交由Spring来管理。。所以该整合，只需将SQLSessionFactory的对象生成器SQLSessionFactoryBean注册到Spring容器中，再将其注入给Dao的实现类即可完成整合。

可以通过2种方式来实现Spring与MyBatis的整合：

• Mapper动态代理
• 支持扫描的Mapper动态代理

一、环境搭建

二、定义映射文件

import java.util.List;

import com.jmu.beans.Student;

//Dao增删改查
public interface IStudentDao {
    void insertStudent(Student student);
    void deleteById(int id);
    void updateStudent(Student student);

    List<String> selectAllStudentsNames();
    String selectStudentNameById(int id);

    List<Student> selectAllStudents();
    Student selectStudentById(int 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="com.jmu.dao.IStudentDao">
    <insert id="insertStudent">
        insert into student(name,age) values(#{name},#{age})
    </insert>

    <delete id="deleteById">
        delete from student where id=#{XXX}
    </delete>

    <update id="updateStudent">
        update student set name=#{name},age=#{age} where id=#{id}
    </update>

    <select id="selectAllStudents" resultType="student">
        select id,name,age from student
    </select>

    <select id="selectStudentById" resultType="student">
        select id,name,age from student where id=#{XXX}
    </select>
</mapper>

三、定义主配置文件

<?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>

    <!--配置别名 -->
    <typeAliases>
        <package name="com.jmu.beans" />
    </typeAliases>

    <mappers>
        <!-- <mapper resource="com/jmu/dao/mapper.xml"/> -->
        <!--xml文件和dao同名 -->
        <package name="com.jmu.dao" />

    </mappers>

</configuration>

四、Mapper动态代理方式生成Dao代理对象

<?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"
    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.xsd">


    <!--注册数据源:C3P0 -->
    <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}" />
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="user" value="${jdbc.user}" />
        <property name="password" value="${jdbc.password}" />
    </bean>

    <!-- 注册属性文件 -->
    <context:property-placeholder location="classpath:jdbc.properties" />
    
    <bean id="mySqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
       <property name="configLocation" value="classpath:mybatis.xml"></property>
       <property name="dataSource" ref="myDataSource"></property>
    </bean>
    
    
    <!--生成Dao的代理对象 -->
    <bean id="studentDao" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="sqlSessionFactory" ref="mySqlSessionFactory" />
        <property name="mapperInterface" value="com.jmu.dao.IStudentDao" />
    </bean>

    <!-- 注册Service -->
    <bean id="studentService" class="com.jmu.service.StudentServiceImpl">
        <property name="dao" ref="studentDao" />
    </bean>
</beans>

五、测试

import java.util.List;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.jmu.beans.Student;
import com.jmu.service.IStudentService;

public class MyTest {

    private IStudentService service;

    @Before
    public void before() {
        //创建容器对象
        String resource = "applicationContext.xml";
        ApplicationContext ac=new ClassPathXmlApplicationContext(resource);  
        service = (IStudentService) ac.getBean("studentService");
    }
    
    @Test
    public void test01() {
        Student student=new Student("张三", 23);
        service.addStudent(student);
    }
    
    @Test
    public void test02() {
        service.removeById(2);        
    }

    @Test
    public void test03() {
        Student student=new Student("王意义", 23);
        student.setId(3);
        service.modifyStudent(student);
    }
    @Test
    public void test04() {
        List<String> names = service.findAllStudentsNames();
        System.out.println(names);
    }
    @Test
    public void test05() {
        String names = service.findStudentNameById(3);
        System.out.println(names);
    }
    
    @Test
    public void test06() {
        List<Student> students=service.findAllStudents();
        for (Student student : students) {
            System.out.println(student);
        }
    }
    
    @Test
    public void test07() {
        Student student=service.findStudentById(3);
        System.out.println(student);
    }
    
    
}

对于IstudentDao.xml中没有写到的List<String> selectAllStudentsNames()和String selectStudentNameById(int id)进行修改

六、支持扫描的动态代理

对于上面的情况，如果有多个Dao接口，就要写多次的以下字段

<!--生成Dao的代理对象 -->
    <bean id="studentDao" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="sqlSessionFactory" ref="mySqlSessionFactory" />
        <property name="mapperInterface" value="com.jmu.dao.IStudentDao" />
    </bean>

<!--生成Dao的代理对象 
     当前配置会被本包中所有的接口生成代理对象
    -->
    <bean  class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="mySqlSessionFactory" />
        <property name="basePackage" value="com.jmu.dao" />
    </bean>

    <!-- 注册Service -->
    <bean id="studentService" class="com.jmu.service.StudentServiceImpl">
         <!-- 这里的Dao的注入需要使用ref属性，且其作为接口的简单类名 -->
        <property name="dao" ref="studentDao" />
    </bean>

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