Spring + SpringMVC+Mybatis 框架整合教程（Eclipse版）

一、开发环境搭建

注意：⚠️ 在搭建环境的时候，稍微注意下版本对应关系，下面是JDK和Tomcat版本对应关系

本教程环境如下所示:

• JDK版本：8\11
• 开发工具：STS 3.9
• 服务器：Tomcat 7.0.52
• Spring：5.2.3
• Lombok：1.18.28

准备好开发工具后，我们先打开STS编辑器，创建一个Spring项目:

创建好之后的项目骨架大概如图所示:

二、整合Spring框架

既然我们包都已经导进去了，我们接下来先整合Spring框架。

• 导入依赖包

• 创建Spring Ioc容器配置文件

打开所有命名空间，省的后面慢慢加

生成的配置文件如下：

<?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:c="http://www.springframework.org/schema/c"
	xmlns:cache="http://www.springframework.org/schema/cache"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:jms="http://www.springframework.org/schema/jms"
	xmlns:lang="http://www.springframework.org/schema/lang"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xmlns:oxm="http://www.springframework.org/schema/oxm"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:task="http://www.springframework.org/schema/task"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:util="http://www.springframework.org/schema/util"
	xmlns:websocket="http://www.springframework.org/schema/websocket"
	xsi:schemaLocation="http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-4.3.xsd
		http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-4.3.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.3.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd
		http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket-4.3.xsd
		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd
		http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-4.3.xsd
		http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-4.3.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

	<!--  包扫描 -->
	<context:component-scan base-package="io.spring.*.*">
		<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
	</context:component-scan>

</beans>

• 编写测试实体

@Component
public class Student {
	public void play() {
		System.out.println("play computer games!");
	}	
}

• 编写测试类

public class TestApp {
	public static void main(String[] args) {
		ApplicationContext context = new ClassPathXmlApplicationContext("classpath:config/spring-config.xml");
		Student student = context.getBean(Student.class);
		student.play();// 打印输出：play computer games!
	}
}

然后你会发现，这种测试类的加载Spring IoC容器，是通过ClassPathXmlApplicationContext去手动加载，但是我们项目是Web应用，应该是跟随应用容器启动的时候去自己加载。

• 删除测试类，修改web.xml的配置

注：🔍 按住Alt+/快捷键，会出现ContextLoaderListener提示，选择它，就会生成代码。

然后web.xml会多出以下配置（修改下spring-config.xml的路径）

<!-- needed for ContextLoaderListener -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:config/spring-config.xml</param-value>
</context-param>
<!-- Bootstraps the root web application context before servlet initialization -->
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

但是到现在为止，我们还是没法进行测试，我们需要把Spring MVC集成进来。

• 新建springmvc-config.xml配置

<?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:c="http://www.springframework.org/schema/c"
	xmlns:cache="http://www.springframework.org/schema/cache"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:jms="http://www.springframework.org/schema/jms"
	xmlns:lang="http://www.springframework.org/schema/lang"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xmlns:oxm="http://www.springframework.org/schema/oxm"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:task="http://www.springframework.org/schema/task"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:util="http://www.springframework.org/schema/util"
	xmlns:websocket="http://www.springframework.org/schema/websocket"
	xsi:schemaLocation="http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-4.3.xsd
		http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-4.3.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.3.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd
		http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket-4.3.xsd
		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd
		http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-4.3.xsd
		http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-4.3.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

	<!-- MVC注解支持 -->
	<mvc:annotation-driven></mvc:annotation-driven>
	<context:component-scan base-package="io.spring.*.action">
		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
	</context:component-scan>
	
	<!-- 视图解析器 -->
	<bean name="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<!-- 后缀:.jsp/.html都可以 -->
		<property name="suffix" value=".jsp"></property>
		<!-- 前缀：pages与WEB-INF同级 -->
		<property name="prefix" value="/pages/"></property>
	</bean>

</beans>

• 修改web.xml配置，配置视图映射

🔍 按住Alt+/快捷键，会出现DispatcherServlet提示，选择它，就会生成代码。

<!-- The front controller of this Spring Web application, responsible for handling all application requests -->
<servlet>
    <servlet-name>springDispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:config/springmvc-config.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>
<!-- Map all requests to the DispatcherServlet for handling -->
<servlet-mapping>
    <servlet-name>springDispatcherServlet</servlet-name>
    <url-pattern>*.asp</url-pattern>
</servlet-mapping>

编写测试接口

package io.spring.test.action;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import io.spring.test.pojo.Student;
@Controller
public class TestAction {
	
	@Autowired
	private Student student;
	
	/**
	 * 这种直接解析视图
	 * @return
	 */
	@RequestMapping("test1.asp")
	public String test1() {
		return "test/test";
	}
	
	/**
	 * 直接返回数据
	 * @return
	 */
	@RequestMapping("test2.asp")
	public @ResponseBody String test2() {
		return student.play();
	}
	
}

测试实体类

package io.spring.test.pojo;
import org.springframework.stereotype.Component;
@Component
public class Student {
	public String play() {
		return "play computer games!";
	}
}

JSP测试页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>测试</title>
</head>
<body>
Hello Spring、Spring MVC!
</body>
</html>

浏览器分别访问http://localhost:8080/ssm-demo/test1.asp、http://localhost:8080/ssm-demo/test2.asp，结果如下

这就意味着我们Spring框架和MVC框架已经成功集成。

三、整合MyBatis框架

在开始之前，我们还是需要主义的就是，版本问题，下面我们来看下版本之间的兼容性说明。

MyBatis-Spring	MyBatis	Spring Framework	Spring Batch	Java
3.0	3.5+	6.0+	5.0+	Java 17+
2.1	3.5+	5.x	4.x	Java 8+
2.0	3.5+	5.x	4.x	Java 8+
1.3	3.4+	3.2.2+	2.1+	Java 6+

所以我们应该选择3.5.x版本的MyBatis，以及2.1版本的MyBatis-spring中间件。

• 下载依赖包

• 项目骨架

• 创建配置文件

1、mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<!-- 如果不集成mybatis-spring,就需要通过XML构建 SqlSessionFactory -->
	<!-- 使用Spring的时候，environments 就是废弃的配置，不使用 -->
	<!-- <properties resource="config/mysql.properties"></properties>
	<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC" />
			<dataSource type="POOLED">
				<property name="driver" value="${driver}" />
				<property name="url" value="${url}" />
				<property name="username" value="{user}" />
				<property name="password" value="${password}" />
			</dataSource>
		</environment>
	</environments> -->
	
	<!-- 设置别名 -->
	<!-- <typeAliases>
		<package name="io.spring.test.pojo"/>
	</typeAliases> -->
	<!-- <typeAliases>
		<typeAlias type="io.spring.test.pojo.Student" alias="student"/>
	</typeAliases> -->
	
	<mappers>
		<mapper resource="/config/mybatis-studentmapper.xml" />
	</mappers>
	
</configuration>

2、mybatis-studentmapper.xml

<!DOCTYPE mapper
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="io.spring.test.mapper.StudentMapper">
  
  <!-- query all students -->
  <select id="queryAll" resultType="student">
    select * from student
  </select>
  
</mapper>

3、mysql.properties

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/spring_test
user=root
password=NJI(mko0

4、spring-config.xml

<?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:c="http://www.springframework.org/schema/c"
	xmlns:cache="http://www.springframework.org/schema/cache"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:jms="http://www.springframework.org/schema/jms"
	xmlns:lang="http://www.springframework.org/schema/lang"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xmlns:oxm="http://www.springframework.org/schema/oxm"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:task="http://www.springframework.org/schema/task"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:util="http://www.springframework.org/schema/util"
	xmlns:websocket="http://www.springframework.org/schema/websocket"
	xsi:schemaLocation="http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-4.3.xsd
		http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-4.3.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.3.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd
		http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket-4.3.xsd
		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd
		http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-4.3.xsd
		http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-4.3.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
	
	<!--  包扫描 -->
	<context:component-scan base-package="io.spring.*.*">
		<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
	</context:component-scan>
	
	<!-- 配置文件加载 -->
	<context:property-placeholder location="classpath:config/mysql.properties"/>
	
	<!-- 数据源 -->
	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="username" value="${user}"></property>
		<property name="password" value="${password}"></property>
		<property name="url" value="${url}"></property>
		<property name="driverClassName" value="${driver}"></property>
	</bean>
	
	<!-- 要和 Spring 一起使用 MyBatis，需要在 Spring 应用上下文中定义至少两样东西：一个 SqlSessionFactory 和至少一个数据映射器类 -->
	<bean class="org.mybatis.spring.SqlSessionFactoryBean">
		<property name="configLocation" value="classpath:/config/mybatis-config.xml"></property>
		<property name="dataSource" ref="dataSource"></property>
		<!-- alias name -->
		<property name="typeAliasesPackage" value="io.spring.*.pojo"></property>
	</bean>
	
	<!-- Mapper代理 -->
	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<property name="basePackage" value="io.spring.*.mapper"></property>
	</bean>
	
</beans>

5、springmvc-config.xml

<?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:c="http://www.springframework.org/schema/c"
	xmlns:cache="http://www.springframework.org/schema/cache"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:jms="http://www.springframework.org/schema/jms"
	xmlns:lang="http://www.springframework.org/schema/lang"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xmlns:oxm="http://www.springframework.org/schema/oxm"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:task="http://www.springframework.org/schema/task"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:util="http://www.springframework.org/schema/util"
	xmlns:websocket="http://www.springframework.org/schema/websocket"
	xsi:schemaLocation="http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-4.3.xsd
		http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-4.3.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.3.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd
		http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket-4.3.xsd
		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd
		http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-4.3.xsd
		http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-4.3.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

	<!-- MVC注解支持 -->
	<mvc:annotation-driven></mvc:annotation-driven>
	<context:component-scan base-package="io.spring.*.action">
		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
	</context:component-scan>
	
	<!-- 视图解析器 -->
	<bean name="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<!-- 后缀:.jsp/.html都可以 -->
		<property name="suffix" value=".jsp"></property>
		<!-- 前缀 -->
		<property name="prefix" value="/pages/"></property>
	</bean>

</beans>

6、TestAction.java

package io.spring.test.action;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import io.spring.test.mapper.StudentMapper;
import io.spring.test.pojo.Student;
import io.spring.test.service.StudentService;
@Controller
public class TestAction {
	
	@Autowired
	private StudentService studentService;
	
	@Autowired
	private Student student;
	
	@RequestMapping("test1.asp")
	public String test1() {
		return "test/test";
	}
	
	@RequestMapping("test2.asp")
	public @ResponseBody String test2() {
		return student.toString();
	}
	
	@RequestMapping("queryAll.asp")
	public @ResponseBody List<Student> queryAll() {
		studentService.queryAll().forEach(System.out::println);
		return null;
	}
	
}

7、StudentMapper.java

package io.spring.test.mapper;
import java.util.List;
import org.springframework.stereotype.Repository;
import io.spring.test.pojo.Student;
@Repository
public interface StudentMapper {
	List<Student> queryAll();
}

8、Stduent.java

package io.spring.test.pojo;
import java.math.BigInteger;
import org.springframework.stereotype.Component;
@Component
public class Student {
	private BigInteger id;
	private String name;
	public Student() {
		super();
	}
	public BigInteger getId() {
		return id;
	}
	public void setId(BigInteger id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + "]";
	}
}

9、StudentService.java

package io.spring.test.service.impl;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import io.spring.test.mapper.StudentMapper;
import io.spring.test.pojo.Student;
import io.spring.test.service.StudentService;
@Service
public class StudentServiceImpl implements StudentService{

	@Autowired
	private StudentMapper studentMapper;
	
	@Override
	public List<Student> queryAll() {
		return studentMapper.queryAll();
	}

}

10、StudentService.java

package io.spring.test.service;
import java.util.List;
import org.springframework.stereotype.Service;
import io.spring.test.pojo.Student;
@Service
public interface StudentService {
	List<Student> queryAll();
}

11、web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
	
	<display-name>ssm-demo</display-name>
	<welcome-file-list>
	  <welcome-file>index.html</welcome-file>
	  <welcome-file>index.htm</welcome-file>
	  <welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
  
	<!-- needed for ContextLoaderListener -->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:config/spring-config.xml</param-value>
	</context-param>
	<!-- Bootstraps the root web application context before servlet initialization -->
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
	
	<!-- The front controller of this Spring Web application, responsible for handling all application requests -->
	<servlet>
		<servlet-name>springDispatcherServlet</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:config/springmvc-config.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<!-- Map all requests to the DispatcherServlet for handling -->
	<servlet-mapping>
		<servlet-name>springDispatcherServlet</servlet-name>
		<url-pattern>*.asp</url-pattern>
	</servlet-mapping>
</web-app>

到这里，浏览器访问接口localhost:8080/ssm-demo/queryAll.asp，控制台输出：

Student [id=1, name=caixibei]
Student [id=2, name=zhangjunhao]
Student [id=3, name=renzhenyu]
Student [id=15, name=caicai]
Student [id=16, name=hh]
Student [id=17, name=caicai]
Student [id=18, name=hh]
Student [id=19, name=caicai]
Student [id=20, name=hh]
Student [id=21, name=caicai]
Student [id=22, name=hh]
Student [id=23, name=caicai]
Student [id=24, name=hh]

四、配置说明

整合了这么久，我们只是一股脑的整合完，但是没有过多的去解释为什么这么做？下面我们简单的说明下。

相信你也看到，我写的这两个配置，也许你不知道为什么我要这样弄，难道仅仅只是因为是为了分开两个概念？不是，只是很有可能会遇到一种情况导致Spring事务失效！

---

客观请看，具体如下所示：

Spring事务: context:exclude-filter。如果带上事务，那么用annotation方式的事务注解和bean配置，事务会失效，要将service　bean配置到xml文件中才行。

🔔 这个问题很经典了！！！ 在主容器中（applicationContext.xml），将Controller的注解排除掉：

<context:component-scan base-package="com">
    <context:exclude-filter type="annotation"expression="org.springframework.stereotype.Controller" />
</context:component-scan>

而在springMVC配置文件中将Service注解给去掉：

<context:component-scan base-package="com">
    <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" />
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service" />
</context:component-scan>

因为spring的context是父子容器，所以会产生冲突，Controller会先进行扫描装配，而此时的Service还没有进行事务的增强处理，得到的将是原样的Service（没有经过事务加强处理，故而没有事务处理能力） ，最后才是applicationContext.xml中的扫描配置进行事务处理。

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这个配置，你也会发现通过mybatis-config.xml再通过**mapper.xml去代理我们的接口，着实麻烦。

我们也可以修改成：

这样一来，我们连mybatis-config.xml文件都可以删除了！

这个是最关键的！我把它删除后，看下会发生什么？

为什么呢？

回过头来看看我们的StudentMapper是个什么玩意儿

他是接口啊！肯定不能实例化啊？所以我们要做的就是让Mapper通过动态代理，生成代理类之后，再去实例化。

---

🔍 思考：既然接口不能注入，那抽象类呢？

答案是：也不能！因为Java不支持多继承，而Mybatis在给类做动态代理（JDK动态代理）的时候，是需要继承$Proxy类的。

🔍 思考：JDK能给类动态代理吗？

答案是：不能。 JDK动态代理只支持接口。