SpringMVC:父子工厂划分（springmvc的耦合问题）

喵俺第一专栏

已于 2022-06-05 18:23:57 修改

阅读量330

点赞数 1

分类专栏： # SpringMVC总结文章标签： mvc SpringMVC spring java

于 2022-06-05 17:38:02 首次发布

本文链接：https://blog.youkuaiyun.com/dengfengling999/article/details/125134089

版权

SpringMVC总结专栏收录该内容

35 篇文章

订阅专栏

从功能角度没有存在问题，但是在设计角度存在缺陷，就是MVC层与其他层次存在耦合，

如果日后，替换了MVC的实现，整体的代码都将受到影响，如果日后把SpringMVC换成Strus2，Webflat的话，换了MVC不仅仅影响MVC的内容，也影响到其他层次

通过两个工厂，解决MVC层与非MVC层之间的耦合

父容器：

子工厂：

diapatcher.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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" 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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!--设置注解扫描的路径 -->
    <context:component-scan base-package="com.baizhiedu"/>
    <!--引入springMVC的核心功能-->

    <mvc:annotation-driven />

    <!--视图解析器配置：    控制器方法返回的结果的前缀和后缀-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

</beans>

在web.xml中添加父容器ContextLoadListener创建工厂：

web.xml：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">


<!--    通过父容器创建工厂解决SpringMVC耦合问题-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
<!--    读取配置文件路径-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
<!--    解决中文乱码问题：Spring给我们提供的过滤器CharacterEncodingFilter-->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>



<!--    初始化servlet-->
<servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!-- 初始化参数:指定SpringMVC配置文件的路径-->
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:dispatcher.xml</param-value>
    </init-param>
    <!-- 本servlet会在tomcat启动的时候，就会被创建-->
    <load-on-startup>1</load-on-startup>
</servlet>
<!--暴露servlet的url的访问路径-->
<servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>
    
</web-app>

父工厂：

applicationContext.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: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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--    包扫描路径-->
    <context:component-scan base-package="com.baizhiedu"/>


    <!--创建连接池-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;charaterEcoding=utf-8"></property>
        <property name="username" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>

    <!--    创建SqlSessionFactory SqlSessionFactoryBean-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--指定数据源-->
        <property name="dataSource" ref="dataSource"></property>
        <!--指定类别名-->
        <property name="typeAliasesPackage" value="com.baizhiedu.entiry"/>
        <!--指定mapper文件-->
        <property name="mapperLocations">
            <!--mapperLocations对应的是数组类型的赋值 spring内置关键字代表src-->
            <list>
                <value>classpath:com.baizhiedu.mapper/*Mapper.xml</value>
            </list>
        </property>
    </bean>

    <!--创建DAO对象 MapperScannerConfigure  -->
    <bean id="confiure" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
        <property name="basePackage" value="com.baizhiedu.dao"></property>
    </bean>

    <!-- 指定额外功能 事务-->
    <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--    整合切面-->
    <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>

</beans>

User：

package com.baizhiedu.entity;

public class User {
    private Integer id;
    private String name;
    private String password;

    public User() {
    }

    public User(Integer id, String name, String password) {
        this.id = id;
        this.name = name;
        this.password = password;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

UserDAO:

package com.baizhiedu.dao;

import com.baizhiedu.entity.User;

public interface UserDAO {
    public void save(User user);
}

UserDAOMapper.xml：

<?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.baizhiedu.dao.UserDAO">
    <!--使用insert，update，delete，select标签来写sql语句-->
    <!--useGeneratedKeys="true"主键自增-->
    <insert id="save" useGeneratedKeys="true">
        insert into tb_users(name,password) values (#{name},#{password})
    </insert>
</mapper>

UserService：

package com.baizhiedu.service;

import com.baizhiedu.entity.User;

public interface UserService {
    public void register(User user);
}

UserServiceImpl：

package com.baizhiedu.service;

import com.baizhiedu.dao.UserDAO;
import com.baizhiedu.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service //使用@Service注解创建这个类的对象
@Transactional //使用注解，添加事务属性
public class UserServiceImpl implements UserService {

    @Autowired //注入userdao
    private UserDAO userDAO;

    @Override
    public void register(User user) {
        userDAO.save(user);
    }
}

控制器：

UserController：

package com.baizhiedu.controller;

import com.baizhiedu.entity.User;
import com.baizhiedu.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/register")
    public String register(User user){
        userService.register(user);
        return "regOk";
    }
}

reg.jsp：

<%--
  Created by IntelliJ IDEA.
  User: DELL
  Date: 2022/6/4
  Time: 18:07
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%>
<html>
<head>
    <title>Title</title>
    <base href="<%=basePath%>">
</head>
<body>
  <form method="post" action="${pageContext.request.contextPath}/user/register">
      UserName:<input type="text" name="name"><br>
      Password:<input type="text" name="password"><br>
      <input type="submit" value="reg">
  </form>
</body>
</html>

regOk.jsp：

<%--
  Created by IntelliJ IDEA.
  User: DELL
  Date: 2022/6/4
  Time: 18:06
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%>
<html>
<head>
    <title>Title</title>
    <base href="<%=basePath%>">
</head>
<body>
   <h1>RegOK</h1>
</body>
</html>

现在的ssm整合开发父子容器处理过程当中是没有事务的，下面打印没有输出create new Transction开启事务

解决：在包扫描上子容器不扫描com.baizhiedu这个包，只让他扫描com.baizhiedu.Controller，这样他就不会创建Service对象，他就会往父容器里面找Service

让zi工厂只创建Controller：

diapatcher.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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" 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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!--设置注解扫描的路径 -->
<!--    设置只扫描conroller包即可，这样就不会创建事务-->
    <context:component-scan base-package="com.baizhiedu.controller"/>
    <!--引入springMVC的核心功能-->

    <mvc:annotation-driven />

    <!--视图解析器配置：    控制器方法返回的结果的前缀和后缀-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

</beans>

让父容器排除创建Controller：

<?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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--    包扫描路径-->
    <context:component-scan base-package="com.baizhiedu">
        <!-- 排除创建Controller-->
        <context:exclude-filter type="aspectj" expression="com.baizhiedu.controller.*"/>
    </context:component-scan>


    <!--创建连接池-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;charaterEcoding=utf-8"></property>
        <property name="username" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>

    <!--    创建SqlSessionFactory SqlSessionFactoryBean-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--指定数据源-->
        <property name="dataSource" ref="dataSource"></property>
        <!--指定类别名-->
        <property name="typeAliasesPackage" value="com.baizhiedu.entiry"/>
        <!--指定mapper文件-->
        <property name="mapperLocations">
            <!--mapperLocations对应的是数组类型的赋值 spring内置关键字代表src-->
            <list>
                <value>classpath:com.baizhiedu.mapper/*Mapper.xml</value>
            </list>
        </property>
    </bean>

    <!--创建DAO对象 MapperScannerConfigure  -->
    <bean id="confiure" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
        <property name="basePackage" value="com.baizhiedu.dao"></property>
    </bean>

    <!-- 指定额外功能 事务-->
    <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--    整合切面-->
    <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>

</beans>

从新运行，添加上了事务：