1，步骤分析

我们先来分析下如何把Spring，SpringMVC，Mybatis整合到一起。

1.1，步骤

①Spring整合上Mybatis
通过Service层，Dao层都注入到Spring容器中。

②引入配置SpringMVC
把Controller层注入SpringMVC容器中

③让web项目启动时自动读取Spring配置文件来创建Spring容器
可以使用ContextLoaderListener来实现Spring容器的创建。

1.2常见疑惑

  • 为什么要使用两个容器？

因为Controller如果不放在MVC容器中，会没有效果，无法处理请求。
而Service如果不放在Spring中，声明式事务也无法使用。

  • SpringMVC容器中的Controller需要依赖Service，能从Spring容器中获取到所依赖的Service对象吗？

Spring容器相当于是父容器，MVC容器相当于是子容器，子容器除了可以使用自己容器中的对象，还可以使用父容器中的对象。

  • 是如何实现这样父子容器的关系的？

  • 是什么时候让两个容器产生这种父子容器的关系的？

在ContextLoaderListener中，会在创建好容器后把容器存入servletContext域。这样在DispathServlet启动时，创建完SpringMVC容器后，会从servletContext域中获取到Spring容器对象，设置为其父容器，这样，子容器就能获取到父容器中的bean了。

2，准备工作

2.1，导入所有依赖

  1. <dependencies>
  2.         <!--Spring-context-->
  3.         <dependency>
  4.             <groupId>org.springframework</groupId>
  5.             <artifactId>spring-context</artifactId>
  6.             <version>5.2.0.RELEASE</version>
  7.         </dependency>
  9.         <!--Aop-->
  10.         <dependency>
  11.             <groupId>org.aspectj</groupId>
  12.             <artifactId>aspectjweaver</artifactId>
  13.             <version>1.8.7</version>
  14.         </dependency>
  16.         <!--spring-jdbc-->
  17.         <dependency>
  18.             <groupId>org.springframework</groupId>
  19.             <artifactId>spring-jdbc</artifactId>
  20.             <version>5.2.0.RELEASE</version>
  21.         </dependency>
  23.         <!--Spring  Mybatis-->
  24.         <dependency>
  25.             <groupId>org.mybatis</groupId>
  26.             <artifactId>mybatis-spring</artifactId>
  27.             <version>2.0.2</version>
  28.         </dependency>
  30.         <!--Mybatis-->
  31.         <dependency>
  32.             <groupId>org.mybatis</groupId>
  33.             <artifactId>mybatis</artifactId>
  34.             <version>3.5.2</version>
  35.         </dependency>
  37.         <!--log4j-->
  38.         <dependency>
  39.             <groupId>log4j</groupId>
  40.             <artifactId>log4j</artifactId>
  41.             <version>1.2.17</version>
  42.         </dependency>
  44.         <!--pageHelper-->
  45.         <dependency>
  46.             <groupId>com.github.pagehelper</groupId>
  47.             <artifactId>pagehelper</artifactId>
  48.             <version>4.0.0</version>
  49.         </dependency>
  51.         <!--mysql-->
  52.         <dependency>
  53.             <groupId>mysql</groupId>
  54.             <artifactId>mysql-connector-java</artifactId>
  55.             <version>5.1.47</version>
  56.         </dependency>
  58.         <!--druid-->
  59.         <dependency>
  60.             <groupId>com.alibaba</groupId>
  61.             <artifactId>druid</artifactId>
  62.             <version>1.1.16</version>
  63.         </dependency>
  65.         <!--junit-->
  66.         <dependency>
  67.             <groupId>junit</groupId>
  68.             <artifactId>junit</artifactId>
  69.             <version>4.13</version>
  70.         </dependency>
  72.         <!--Spring junit-->
  73.         <dependency>
  74.             <groupId>org.springframework</groupId>
  75.             <artifactId>spring-test</artifactId>
  76.             <version>5.2.0.RELEASE</version>
  77.         </dependency>
  79.         <!--Lombok-->
  80.         <dependency>
  81.             <groupId>org.projectlombok</groupId>
  82.             <artifactId>lombok</artifactId>
  83.             <version>1.18.20</version>
  84.         </dependency>
  86.         <!--servlet-->
  87.         <dependency>
  88.             <groupId>javax.servlet</groupId>
  89.             <artifactId>javax.servlet-api</artifactId>
  90.             <version>3.1.0</version>
  91.             <scope>provided</scope>
  92.         </dependency>
  94.         <!--jsp-->
  95.         <dependency>
  96.             <groupId>javax.servlet.jsp</groupId>
  97.             <artifactId>jsp-api</artifactId>
  98.             <version>2.2</version>
  99.         </dependency>
  101.         <!--SpringMVC-->
  102.         <dependency>
  103.             <groupId>org.springframework</groupId>
  104.             <artifactId>spring-webmvc</artifactId>
  105.             <version>5.2.0.RELEASE</version>
  106.         </dependency>
  108.         <!--json-->
  109.         <dependency>
  110.             <groupId>com.fasterxml.jackson.core</groupId>
  111.             <artifactId>jackson-databind</artifactId>
  112.             <version>2.9.0</version>
  113.         </dependency>
  115.         <!--commons-->
  116.         <dependency>
  117.             <groupId>commons-fileupload</groupId>
  118.             <artifactId>commons-fileupload</artifactId>
  119.             <version>1.4</version>
  120.         </dependency>
  121.     </dependencies>

2.2，数据库

  1. DROP TABLE IF EXISTS `user`;
  2. CREATE TABLE `user`  (
  3.   `id` int(11) NOT NULL AUTO_INCREMENT,
  4.   `username` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  5.   `age` int(11) DEFAULT NULL,
  6.   `address` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  7.   PRIMARY KEY (`id`) USING BTREE
  8. ) ENGINE = InnoDB AUTO_INCREMENT = 3 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;
  10. INSERT INTO `user` VALUES (1, 'UZI', 19, '上海');
  11. INSERT INTO `user` VALUES (2, 'PDD', 25, '上海');

2.3，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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       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 http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">

    <!--组件扫描，排除controller-->
    <context:component-scan base-package="domain">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"></context:exclude-filter>
    </context:component-scan>

    <!--读取properties文件-->
    <context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder>

    <!--创建连接池注入容器-->
    <bean class="com.alibaba.druid.pool.DruidDataSource" id="dataSource">
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
        <property name="driverClassName" value="${jdbc.driver}"></property>
    </bean>
    <!--spring整合mybatis后控制的创建获取SqlSessionFactory的对象-->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean" id="sessionFactory">
        <!--配置连接池-->
        <property name="dataSource" ref="dataSource"></property>
        <!--配置mybatis配置文件的路径-->
        <property name="configLocation" value="classpath:mybatis-config.xml"></property>
    </bean>

    <!--mapper扫描配置，扫描到的mapper对象会被注入Spring容器中-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer" id="mapperScannerConfigurer">
        <property name="basePackage" value="dao"></property>
    </bean>

    <!--开启aop注解支持-->
    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>

    <!--声明式事务相关配置-->
    <bean class="org.springframework.jdbc.datasource.DataSourceTransactionManager" id="transactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"></tx:annotation-driven>

</beans>

2.4，jdbc.properties

jdbc.url=jdbc:mysql://localhost:3306/mybatis_db?useUnicode=true&characterEncoding=UTF-8&serverTime=UTC
jdbc.driver=com.mysql.jdbc.Driver
jdbc.username=root
jdbc.password=123456

2.5，mybatis-config.xml

<?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>
    <!--指定使用log4j打印Mybatis日志-->
    <settings>
        <setting name="logImpl" value="LOG4J"/>
    </settings>

    <!--配置别名-->
    <typeAliases>
        <package name="domain"/>
    </typeAliases>

    <plugins>
        <!--注意：分页助手的插件，配置通用mapper之前-->
        <plugin interceptor="com.github.pagehelper.PageHelper">
            <!--指定方言-->
            <property name="dialect" value="mysql"/>
        </plugin>
    </plugins>
</configuration>

2.6，log4j.properties

### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### direct messages to file mylog.log ###
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=c:/mylog.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### set log levels - for more verbose logging change 'info' to 'debug' ###

log4j.rootLogger=debug, stdout

2.7，spring-mvc.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"
       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">
    <!--
         SpringMVC只扫描controller包即可
     -->
    <context:component-scan base-package="controller"/>
    <!-- 解决静态资源访问问题，如果不加mvc:annotation-driven会导致无法访问handler-->
    <mvc:default-servlet-handler/>
    <!--解决响应乱码-->
    <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="utf-8"/>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>


    <!--配置视图解析器  前后端不分离项目使用-->
    <!--    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="viewResolver">
            &lt;!&ndash;要求拼接的前缀&ndash;&gt;
            <property name="prefix" value="/WEB-INF/page/"></property>
            &lt;!&ndash;要拼接的后缀&ndash;&gt;
            <property name="suffix" value=".jsp"></property>
        </bean>-->

    <!--配置拦截器-->
    <!--    <mvc:interceptors>

            <mvc:interceptor>
                &lt;!&ndash;
                &ndash;&gt;
                <mvc:mapping path="/**"/>
                &lt;!&ndash;配置排除拦截的路径&ndash;&gt;
                <mvc:exclude-mapping path="/"/>
                &lt;!&ndash;配置拦截器对象注入容器&ndash;&gt;
                <bean class=""></bean>
            </mvc:interceptor>
        </mvc:interceptors>-->
    <!--
          文件上传解析器
          注意：id 必须为 multipartResolver
          如果需要上传文件时可以放开相应配置
      -->
    <!--<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">-->
    <!--&lt;!&ndash; 设置默认字符编码 &ndash;&gt;-->
    <!--<property name="defaultEncoding" value="utf-8"/>-->
    <!--&lt;!&ndash; 一次请求上传的文件的总大小的最大值，单位是字节&ndash;&gt;-->
    <!--<property name="maxUploadSize" value="#{1024*1024*100}"/>-->
    <!--&lt;!&ndash; 每个上传文件大小的最大值，单位是字节&ndash;&gt;-->
    <!--<property name="maxUploadSizePerFile" value="#{1024*1024*50}"/>-->
    <!--</bean>-->
</beans>

2.8，修改web.xml

 <!--配置spring的配置文件路径-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <!--配置监听器，可以再应用被部署的时候创建spring容器-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--
            为DispatcherServlet提供初始化参数的
            设置springmvc配置文件的路径
                name是固定的，必须是contextConfigLocation
                value指的是SpringMVC配置文件的位置
         -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <!--
            指定项目启动就初始化DispatcherServlet
         -->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <!--
             /           表示当前servlet映射除jsp之外的所有请求（包含静态资源）
             *.do        表示.do结尾的请求路径才能被SpringMVC处理(老项目会出现)
             /*          表示当前servlet映射所有请求（包含静态资源,jsp），不应该使用其配置DispatcherServlet
         -->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--乱码处理过滤器，由SpringMVC提供-->
    <!-- 处理post请求乱码 -->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <!-- name固定不变，value值根据需要设置 -->
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <!-- 所有请求都设置utf-8的编码 -->
        <url-pattern>/*</url-pattern>
    </filter-mapping>