介绍SSM框架

介绍SSM框架<原理>

一、什么是SSM框架？

SSM框架是spring、spring MVC 、和mybatis框架的整合，是标准的MVC模式。SSM框架即是将SpringMVC框架、Spring框架、MyBatis框架整合使用。以简化在web开发中繁琐、重复的操作，让开发人员的精力专注于业务处理的开发上。标准的SSM框架有四层，分别是dao层（mapper），service层，controller层和View层。使用spring实现业务对象管理，使用spring MVC负责请求的转发和视图管理，mybatis作为数据对象的持久化引擎。

二、系统架构图

三、搭建步骤

SSM框架搭建实现步骤

（1）创建Web项目

创建项目包结构

pom文件依赖

 <dependencies>
        <!-- Mybatis核心 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>
        <!-- junit测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!-- MySQL驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <!--spring-webmvc-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.1</version>
        </dependency>
        <!-- 导入thymeleaf与spring5的整合包 -->
        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf-spring5</artifactId>
            <version>3.0.12.RELEASE</version>
        </dependency>

        <!-- 导入jackson的依赖 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.12.1</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.18</version>
        </dependency>
        <!-- spring与jdbc连接spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.1</version>
        </dependency>
    </dependencies>

db.properties

#key=value
db.driver=com.mysql.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/yubencheng
db.username=root
db.password=root

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: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/aop https://www.springframework.org/schema/aop/spring-aop.xsd">


    <context:component-scan base-package="com.huiqiao.service"></context:component-scan>

</beans>

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>

    <!-- <properties>
         <property name="driver" value="com.mysql.jdbc.Driver"/>
         <property name="url" value="jdbc:mysql://localhost:3306/yubencheng"/>
     </properties>-->


    <settings>
        <!-- 是否开启驼峰命名自动映射 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!-- 开启懒加载,全局开启 -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- （在 3.4.1 及之前的版本中aggressiveLazyLoading默认为 true） -->
        <setting name="aggressiveLazyLoading" value="false"/>
        <!-- 二级缓存 默认是开启的，不需要手动配置 -->
        <setting name="cacheEnabled" value="true"/>
    </settings>


</configuration>

applicationContext-mybatis.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">

    <!-- 加载属性文件 -->
    <context:property-placeholder location="classpath:db.properties"></context:property-placeholder>

    <!-- 配置数据源 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
        <property name="driverClassName" value="${db.driver}"></property>
        <property name="url" value="${db.url}"></property>
        <property name="username" value="${db.username}"></property>
        <property name="password" value="${db.password}"></property>
    </bean>
    <!-- 整合sqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="configLocation" value="classpath:mybatis-config.xml"></property>
        <property name="mapperLocations" value="classpath:mapper/*.xml"></property>
    </bean>

    <!-- 专门扫描mapper接口 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.huiqiao.mapper"></property>
    </bean>


    <!-- 数据源事务管理器 ioc,指定管理的数据源 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <!-- 开启事务注解驱动 -->
    <tx:annotation-driven transaction-manager="transactionManager"></tx:annotation-driven>


    <!-- 事务管理器增强，配置方法的事务传播机制 -->
   <!-- <tx:advice id="transactionManager" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="add*" propagation="REQUIRED"/>
            <tx:method name="update*" propagation="REQUIRED"/>
            <tx:method name="del*" propagation="REQUIRED"/>
            <tx:method name="get*" propagation="REQUIRED" read-only="true"/>
        </tx:attributes>
    </tx:advice>-->
</beans>

application-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">

    <!-- 开启注解扫描 -->
    <context:component-scan base-package="com.huiqiao.controller"></context:component-scan>

    <!--
	path：设置处理的请求地址
	view-name：设置请求地址所对应的视图名称
    -->
<!--    <mvc:view-controller path="/" view-name="index"></mvc:view-controller>-->

    <!--必须通过文件解析器的解析才能将文件转换为MultipartFile对象-->
<!--    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"></bean>-->

    <!-- 配置视图解析器【解析视图（设置视图前缀&后缀）】 -->
    <!-- 配置Thymeleaf视图解析器 -->
    <bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="order" value="1"/>
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">

                        <!-- 视图前缀 -->
                        <property name="prefix" value="/WEB-INF/"/>

                        <!-- 视图后缀 -->
                        <property name="suffix" value=".html"/>
                        <property name="templateMode" value="HTML5"/>
                        <property name="characterEncoding" value="UTF-8" />
                    </bean>
                </property>
            </bean>
        </property>
    </bean>

    <!--
   处理静态资源，例如html、js、css、jpg
  若只设置该标签，则只能访问静态资源，其他请求则无法访问
  此时必须设置<mvc:annotation-driven/>解决问题
 -->
    <!--    解决静态资源加载问题-->
    <mvc:default-servlet-handler></mvc:default-servlet-handler>

    <!-- 当SpringMVC中设置任何一个view-controller时，
    其他控制器中的请求映射将全部失效，此时需要在SpringMVC的核心配置文件中设置开启mvc注解驱动的标签： -->
    <mvc:annotation-driven />

  <!--  <bean id="firstInterceptor" class="com.huiqiao.interceptor.FirstInterceptor"></bean>-->
    <!-- 以上两种配置方式都是对DispatcherServlet所处理的所有的请求进行拦截 -->
  <!--  <mvc:interceptors>
        &lt;!&ndash; 全局拦截 &ndash;&gt;
       &lt;!&ndash; <ref bean="firstInterceptor"></ref>&ndash;&gt;
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <ref bean="firstInterceptor"></ref>
        </mvc:interceptor>
    </mvc:interceptors>-->
    <!--
        以上配置方式可以通过ref或bean标签设置拦截器，通过mvc:mapping设置需要拦截的请求，通过mvc:exclude-mapping设置需要排除的请求，即不需要拦截的请求
    -->

    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <property name="exceptionMappings">
            <props>
                <!--
                    properties的键表示处理器方法执行过程中出现的异常
                    properties的值表示若出现指定异常时，设置一个新的视图名称，跳转到指定页面
                -->
                <prop key="java.lang.NullPointerException">error</prop>
            </props>
        </property>
        <!--
            exceptionAttribute属性设置一个属性名，将出现的异常信息在请求域中进行共享
        -->
        <!--<property name="exceptionAttribute" value="ex"></property>-->
    </bean>

</beans>

web.xm

<?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">

    <!--配置springMVC的编码过滤器-->
    <filter>
        <filter-name>CharacterEncodingFilter</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>
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!-- HiddenHttpMethodFilter,RESTful实现 -->
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <servlet>
        <servlet-name>springMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!-- 设置springmvc.xml配置文件路径【管理容器对象】 -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
           <!-- <param-value>classpath:application-mvc.xml</param-value>-->
            <param-value>classpath:application-mvc.xml</param-value>
        </init-param>
        <!-- 设置DispatcherServlet优先级【启动服务器时，创建当前Servlet对象】 -->
        <!--
       作为框架的核心组件，在启动过程中有大量的初始化操作要做
      而这些操作放在第一次请求时才执行会严重影响访问速度
      因此需要通过此标签将启动控制DispatcherServlet的初始化时间提前到服务器启动时
         -->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springMVC</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>


    <!-- 配置Spring的配置文件 去加载spring的配置文件 -->
    <listener>
        <!-- 默认是去WEB-INF下找 applicationContext.xml配置文件 -->
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext*.xml</param-value>
    </context-param>
</web-app>