sping+springmvc的框架中，IOC容器的加载过程
http://my.oschina.net/xianggao/blog/596476
基本上是先加载ContextLoaderListener，然后生成一个ioc容器。
然后再实例化DispatchServlet时候在加载对应的配置文件，再次生成Controller相关的IOC容器
关于上面两个容器关系：
ContextLoaderListener中创建ApplicationContext主要用于整个Web应用程序需要共享的一些组件，比如DAO，数据库的ConnectionFactory等。而由DispatcherServlet创建的ApplicationContext主要用于和该Servlet相关的一些组件，比如Controller、ViewResovler等。
对于作用范围而言，在DispatcherServlet中可以引用由ContextLoaderListener所创建的ApplicationContext，而反过来不行。
于是，如果对于这两份配置没有很好的认识，就会发生重复加载配置文件，导致bean被多次加载的问题：
http://my.oschina.net/xianggao/blog/522267#OSC_h1_4
总结：
1、通过配置exclude-filter来避免重复加载的问题
-
<context:component-scan base-package="com.projects.system">
-
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/>
-
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
-
</context:component-scan>
2、分开扫描，养成良好习惯：
DispatchServlet.xml <context:component-scan base-package="xx.xx.xx.controller" />
applicationContext.xml <context:component-scan base-package="xx.xxx.xx.dao,xx.xx.xxx.service"/>
#1 问题描述# 在车保养项目开发过程中，技术架构：Spring MVC + MyBatis；Service层接口中属性，如果使用注解@Value注入，不能够拿到Properties文件中拿到对应的key值；但在Spring配置文件applicationContext-xxx.xml文件中配置的Properties就可以拿到。具体项目中相关代码如下：
Spring MVC的dispatcher-servlet.xml文件：
<?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:mvc="http://www.springframework.org/schema/mvc"
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-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!-- 自定义的参数解析器放在第一位置 -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<!-- 自定义参数解析器 -->
<property name="customArgumentResolvers">
<list>
<bean class="com.qding.base.resolver.ArgumentFromJsonResolver" />
</list>
</property>
</bean>
<!-- 开启组件扫描 -->
<!-- 对包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 -->
<context:component-scan base-package="com.qding"/>
<!-- 开启注解 -->
<mvc:annotation-driven />
<!-- 启用AspectJ对Annotation的支持 -->
<aop:aspectj-autoproxy proxy-target-class="true"/>
<!-- 静态资源路径 -->
<mvc:resources location="/easyui/" mapping="/easyui/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<mvc:resources location="/html/" mapping="/html/**"/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp" />
</bean>
<!-- 配置多请求数据类型，如json xml-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- set the max upload size10MB -->
<property name="defaultEncoding" value="UTF-8" />
<property name="maxUploadSize" value="10485760" />
<property name="maxInMemorySize" value="10240" />
</bean>
<!-- 配置Controller拦截器 -->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**" />
<mvc:exclude-mapping path="/remote/imessage"/>
<mvc:exclude-mapping path="/easyui/**"/>
<mvc:exclude-mapping path="/js/**"/>
<mvc:exclude-mapping path="/html/**"/>
<bean class="com.qding.base.interceptor.TransferSecurityInterceptor"/>
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/**" />
<mvc:exclude-mapping path="/remote/imessage"/>
<mvc:exclude-mapping path="/easyui/**"/>
<mvc:exclude-mapping path="/js/**"/>
<mvc:exclude-mapping path="/html/**"/>
<bean class="com.qding.doc.interceptor.TransferDocInterceptor"/>
</mvc:interceptor>
</mvc:interceptors>
<!-- 切面配置：Controller方法参数校验 -->
<bean class="com.qding.base.aspect.ParameterValidateAspect" />
</beans>
Spring的applicationContext-service.xml文件：
<?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:task="http://www.springframework.org/schema/task"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/task
http://www.springframework.org/schema/task/spring-task.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!-- 开启组件扫描 -->
<!-- 对包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 -->
<context:component-scan base-package="com.qding.*.*.service"/>
<!-- 定时任务 -->
<task:annotation-driven/>
<!-- 启用AspectJ对Annotation的支持 -->
<aop:aspectj-autoproxy/>
<!-- Transaction Support -->
<tx:advice id="useTxAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="*remove*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception"/>
<tx:method name="*save*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="*modify*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="*update*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="create*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="fill*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="cancel*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="*chang*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="find*" propagation="SUPPORTS"/>
<tx:method name="get*" propagation="SUPPORTS"/>
<tx:method name="query*" propagation="SUPPORTS"/>
<tx:method name="page*" propagation="SUPPORTS"/>
<tx:method name="count*" propagation="SUPPORTS"/>
</tx:attributes>
</tx:advice>
<!--把事务控制在Service层-->
<aop:config>
<aop:pointcut id="pc" expression="execution(public * com.qding..service.*.*(..))" />
<aop:advisor pointcut-ref="pc" advice-ref="useTxAdvice" />
</aop:config>
<!-- 切面配置：Service层方法执行日志 -->
<bean class="com.qding.aspect.ServiceVersionLogAspect" />
<!--memcached客户端配置-->
<bean name="xmemcachedClientBuilder" class="net.rubyeye.xmemcached.XMemcachedClientBuilder">
<constructor-arg>
<list>
<bean class="java.net.InetSocketAddress">
<constructor-arg>
<value>${server_1}</value>
</constructor-arg>
<constructor-arg>
<value>${port_1}</value>
</constructor-arg>
</bean>
</list>
</constructor-arg>
<constructor-arg>
<list>
<value>${priority_1}</value>
</list>
</constructor-arg>
<property name="connectionPoolSize" value="6"/>
<property name="commandFactory">
<bean class="net.rubyeye.xmemcached.command.BinaryCommandFactory"/>
</property>
<property name="sessionLocator">
<bean class="net.rubyeye.xmemcached.impl.KetamaMemcachedSessionLocator"/>
</property>
<property name="transcoder">
<bean class="net.rubyeye.xmemcached.transcoders.SerializingTranscoder" />
</property>
</bean>
<bean name="xmemcachedClient" factory-bean="xmemcachedClientBuilder" factory-method="build" destroy-method="shutdown">
<property name="opTimeout" value="3000"/>
</bean>
<bean id="memCacheUtil" class="com.qding.member.common.cache.MemCacheUtil">
<!-- 过期时间 单位秒 -->
<property name="expTime" value="3600"/>
<!-- 操作失效时间 单位毫秒 -->
<property name="opTime" value="3000"/>
<property name="memcachedClient" ref="xmemcachedClient"/>
</bean>
</beans>
Service层OrderServiceImpl的代码：
public class OrderServiceImpl implements OrderService {
@Value("${bopai.provider_id}")
private String bopaiProviderId;
@Value("${bopai.provider_name}")
private String bopaiProviderName;
@Value("${bopai.connect.phone}")
private String boPaiPhone;
......
}
#2 排查过程#
Spring的applicationContext-service.xml文件配置的属性，可以正常拿到Properties文件中的值；【正常】
项目工程的Service层OrderServiceImpl实现，@Value不能拿到Properties文件中的值；【不正常】
代码断点调试：发现OrderServiceImpl被初始化了两次，第一次@Value可以拿到值，第二次@Value没有拿到值；【不正常】
发现根本原因：Spring 容器和Spring MVC容器分别都初始化了Service的实例，后者第二次初始化Service实例时，没有拿到@Value值，该实例覆盖掉了Spring 容器初始化的实例；
#3 解决方案# 通过修改两个配置文件的<context:component-scan base-package=""/>扫包范围，达到以下效果：
Spring MVC的配置文件dispatcher-servlet严格限制只初始化Controller层实例；
Spring的配置文件applicationContext-service.xml严格限制只初始化除Controller层的其他层实例；
修改后的配置文件：
Spring MVC的dispatcher-servlet.xml文件：
<?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:mvc="http://www.springframework.org/schema/mvc"
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-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!-- 自定义的参数解析器放在第一位置 -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<!-- 自定义参数解析器 -->
<property name="customArgumentResolvers">
<list>
<bean class="com.qding.base.resolver.ArgumentFromJsonResolver" />
</list>
</property>
</bean>
<!-- 开启组件扫描 -->
<!-- 对包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 -->
<context:component-scan base-package="com.qding.*.*.controller,com.qding.*.controller"/>
<!-- 开启注解 -->
<mvc:annotation-driven />
<!-- 启用AspectJ对Annotation的支持 -->
<aop:aspectj-autoproxy proxy-target-class="true"/>
<!-- 静态资源路径 -->
<mvc:resources location="/easyui/" mapping="/easyui/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<mvc:resources location="/html/" mapping="/html/**"/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp" />
</bean>
<!-- 配置多请求数据类型，如json xml-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- set the max upload size10MB -->
<property name="defaultEncoding" value="UTF-8" />
<property name="maxUploadSize" value="10485760" />
<property name="maxInMemorySize" value="10240" />
</bean>
<!-- 配置Controller拦截器 -->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**" />
<mvc:exclude-mapping path="/remote/imessage"/>
<mvc:exclude-mapping path="/easyui/**"/>
<mvc:exclude-mapping path="/js/**"/>
<mvc:exclude-mapping path="/html/**"/>
<bean class="com.qding.base.interceptor.TransferSecurityInterceptor"/>
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/**" />
<mvc:exclude-mapping path="/remote/imessage"/>
<mvc:exclude-mapping path="/easyui/**"/>
<mvc:exclude-mapping path="/js/**"/>
<mvc:exclude-mapping path="/html/**"/>
<bean class="com.qding.doc.interceptor.TransferDocInterceptor"/>
</mvc:interceptor>
</mvc:interceptors>
<!-- 切面配置：Controller方法参数校验 -->
<bean class="com.qding.base.aspect.ParameterValidateAspect" />
</beans>
Spring的applicationContext-service.xml文件：
<?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:task="http://www.springframework.org/schema/task"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/task
http://www.springframework.org/schema/task/spring-task.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!-- 开启组件扫描 -->
<!-- 对包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 -->
<context:component-scan base-package="com.qding.*.*.service,com.qding.*.*.imessage,com.qding.*.quartz,com.qding.remote.service"/>
<!-- 定时任务 -->
<task:annotation-driven/>
<!-- 启用AspectJ对Annotation的支持 -->
<aop:aspectj-autoproxy/>
<!-- Transaction Support -->
<tx:advice id="useTxAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="*remove*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception"/>
<tx:method name="*save*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="*modify*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="*update*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="create*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="fill*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="cancel*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="*chang*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception" />
<tx:method name="find*" propagation="SUPPORTS"/>
<tx:method name="get*" propagation="SUPPORTS"/>
<tx:method name="query*" propagation="SUPPORTS"/>
<tx:method name="page*" propagation="SUPPORTS"/>
<tx:method name="count*" propagation="SUPPORTS"/>
</tx:attributes>
</tx:advice>
<!--把事务控制在Service层-->
<aop:config>
<aop:pointcut id="pc" expression="execution(public * com.qding..service.*.*(..))" />
<aop:advisor pointcut-ref="pc" advice-ref="useTxAdvice" />
</aop:config>
<!-- 切面配置：Service层方法执行日志 -->
<bean class="com.qding.aspect.ServiceVersionLogAspect" />
<!--memcached客户端配置-->
<bean name="xmemcachedClientBuilder" class="net.rubyeye.xmemcached.XMemcachedClientBuilder">
<constructor-arg>
<list>
<bean class="java.net.InetSocketAddress">
<constructor-arg>
<value>${server_1}</value>
</constructor-arg>
<constructor-arg>
<value>${port_1}</value>
</constructor-arg>
</bean>
</list>
</constructor-arg>
<constructor-arg>
<list>
<value>${priority_1}</value>
</list>
</constructor-arg>
<property name="connectionPoolSize" value="6"/>
<property name="commandFactory">
<bean class="net.rubyeye.xmemcached.command.BinaryCommandFactory"/>
</property>
<property name="sessionLocator">
<bean class="net.rubyeye.xmemcached.impl.KetamaMemcachedSessionLocator"/>
</property>
<property name="transcoder">
<bean class="net.rubyeye.xmemcached.transcoders.SerializingTranscoder" />
</property>
</bean>
<bean name="xmemcachedClient" factory-bean="xmemcachedClientBuilder" factory-method="build" destroy-method="shutdown">
<property name="opTimeout" value="3000"/>
</bean>
<bean id="memCacheUtil" class="com.qding.member.common.cache.MemCacheUtil">
<!-- 过期时间 单位秒 -->
<property name="expTime" value="3600"/>
<!-- 操作失效时间 单位毫秒 -->
<property name="opTime" value="3000"/>
<property name="memcachedClient" ref="xmemcachedClient"/>
</bean>
</beans>
#4 问题总结# SpringMVC容器是Spring容器的一个子容器，它同样能够初始化实体类。由于SpringMVC容器的初始化是在Spring容器初始化之后，所以它会替换Spring中已经存在的类，这样可能会导致冲突。因此在Spring的配置文件中SpringMVC和Spring容器各司其职，在使用ComponentScan进行扫描时，各自扫描各自的实体类。如下配置：
Spring容器扫描配置：
<context:component-scan base-package="com.projects.system">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
</context:component-scan>
SpringMVC容器扫描配置：
<context:component-scan base-package="com.projects.system">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/>
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
</context:component-scan>
以上配置在使用Spring xml-based配置时是没有问题的。如果在项目中引入java-base配置时，同时引入了@Configuration注解，@Configuration注解是在Spring容器初始化时进行实体类的初始化工作，因此在Spring MVC扫描配置中要将其过滤掉，否则会导致SpringMVC 的rest地址不可访问的问题。新的配置如下：
<context:component-scan base-package="com.projects.system">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/>
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
<!-- 不扫描配置文件类，避免重复初始化 -->
<context:exclude-filter type="annotation" expression="org.springframework.context.annotation.Configuration"/>
</context:component-scan>