SSM框架整合思想

Spring+Mybatis+SpringMVC框架是目前流行的Java框架组合。
整合整体分为三层：Dao层，Service层和表现层。
以maven项目为例，建立一个聚合工程，每个层次都是一个模块分别来搭建配置

Dao层

Dao层用来与数据库进行交互，并且将与数据库交互的结果返回给Service层。
在Dao层需要用到的JAR包有：

1. mybatis的jar包
2. 数据库驱动包（MySql或者Oracle等等）
3. 数据库连接池（C3P0等）
4. Mybatis和Spring的整合包
5. Spring的jar包

配置文件：
1. Mybatis的配置文件
2. Spring的配置文件
spring配置的文件主要配置数据库的数据源，数据库的连接池，SqlSessionFactory（Mybatis和Spring整合包）和mapper扫描器。
mybatis配置文件

<configuration>

configuration>

只包含了约束，没有进行配置，因为数据库的相关配置都有Spring来管理。
Spring配置文件

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

    
    
    <context:property-placeholder location="classpath:properties/*.properties" />
    
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
        destroy-method="close">
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="maxActive" value="10" />
        <property name="minIdle" value="5" />
    bean>
    
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        
        <property name="dataSource" ref="dataSource" />
        
        <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml" />
    bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.xxx.mapper" />
    bean>
beans>

applicationContext-dao.xml主要配置了连接池，SqlSessionFactory和加载mybatis的配置文件的设置。使用了properties文件来加载数据库的属性。

Service层

Service层主要扫描Service层的注解，配置事务管理器。
需要Spring相关的jar包。
applicationContext-service.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

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

beans>

applicationContext-service.xml配以一个包扫描器，扫描指定包下的带有@Service的注解的类。
事务applicationContext-tx.xml的配置

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
    
    <bean id="transactionManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        
        <property name="dataSource" ref="dataSource" />
    bean>
    
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            
            <tx:method name="save*" propagation="REQUIRED" />
            <tx:method name="insert*" propagation="REQUIRED" />
            <tx:method name="add*" propagation="REQUIRED" />
            <tx:method name="create*" propagation="REQUIRED" />
            <tx:method name="delete*" propagation="REQUIRED" />
            <tx:method name="update*" propagation="REQUIRED" />
            <tx:method name="find*" propagation="SUPPORTS" read-only="true" />
            <tx:method name="select*" propagation="SUPPORTS" read-only="true" />
            <tx:method name="get*" propagation="SUPPORTS" read-only="true" />
        tx:attributes>
    tx:advice>
    
    <aop:config>
        <aop:advisor advice-ref="txAdvice"
            pointcut="execution(* com.xxx.service.*.*(..))" />
    aop:config>
beans>

配置了事务Spring的事务管理器，每一类方法的事务传播方式，事务的切面等。

表现层

表现层用来接收客户端传过来的请求，并且将服务器的处理结果作为响应返回给客户端。主要用到了springmvc和spring的jar包。
配置文件springmvc.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

        
    <context:component-scan base-package="com.xxx.controller">context:component-scan>
    
    <mvc:annotation-driven/>
    
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    bean>
beans>        

配置了注解驱动，包扫描器用来扫描@Controller注解。还有一个视图解析器，属性值为视图界面文件的前缀路径和后缀文件名。

web.xml

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    id="taotao" version="2.5">
    <display-name>taotao-managerdisplay-name>
    <welcome-file-list>
        <welcome-file>index.htmlwelcome-file>
        <welcome-file>index.htmwelcome-file>
        <welcome-file>index.jspwelcome-file>
        <welcome-file>default.htmlwelcome-file>
        <welcome-file>default.htmwelcome-file>
        <welcome-file>default.jspwelcome-file>
    welcome-file-list>
    
    <context-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath:spring/applicationContext-*.xmlparam-value>
    context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
    listener>

    
    <filter>
        <filter-name>CharacterEncodingFilterfilter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
        <init-param>
            <param-name>encodingparam-name>
            <param-value>utf-8param-value>
        init-param>
    filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilterfilter-name>
        <url-pattern>/*url-pattern>
    filter-mapping>


    
    <servlet>
        <servlet-name>servletnameservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
        
        <init-param>
            <param-name>contextConfigLocationparam-name>
            <param-value>classpath:spring/springmvc.xmlparam-value>
        init-param>
        <load-on-startup>1load-on-startup>
    servlet>
    <servlet-mapping>
        <servlet-name>servletnameservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
web-app>