spring web.xml applicationContext.xml常见配置

web.xml可以说是web项目的入口，spring struts2,springMVC，包括一些日志框架log4j，权限管理框架shiro等都是通过web.xml作为入口的。

先看一个web.xml的例子

<?xml version="1.0" encoding="UTF-8"?>
<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="WebApp_ID" version="2.5">
<display-name>fundamental</display-name>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:applicationContext.xml</param-value>
</context-param>
<context-param>
<param-name>webAppRootKey</param-name>
<param-value>WORKDIR</param-value>
</context-param>
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:log4j.properties</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>
<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>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>Loader.jsp</welcome-file>
</welcome-file-list>

</web-app>

解析：

<context-param> + <listener> -> <filter> -> <servlet>

applicationContext.xml是spring管理bean的配置文件，例如datasource的配置，controller的配置，service的配置等。

在appicationContext.xml中可以引入*.properties进行配置，当然，properties是以key-value的形式存储的，引入的配置文件写法，如下：

<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:config.properties</value>
</list>
</property>
</bean>用的时候，通过$符号进行引用。例如：${key}就能拿到properties中的value值。