Servlet初始配置 监听器和过滤器

ServletContext:application范围内的参数

此所设定的参

来源： http://note.sdo.com/my

数，在JSP网页中可以使用下列方法来取得：

${initParam.param0},

<%=application.getInitParameter("param0") %><br/>

若在Servlet可以使用下列方法来获得：

String param_name=getServletContext().getInitParameter("param0")

=this.getServletConfig().getServletContext().getInitParameter("param0")

=application.getInitParameter("param0");

使用上下文初始化参数:

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<context-param>             <param-name>param_name</param-name>             <param-value>avalible during application</param-value>    </context-param> <context-param>      <param-name>contextConfigLocation</param-name>      <param-value>/WEB-INF/spring-configuration/*.xml</param-value>  </context-param>

<wiz_tmp_tag class="wiz-block-scroll">

 

部署在同一容器中的多个Web项目，要配置不同的webAppRootKey，web.xml文件中最好定义webAppRootKey参数，如果不定义，将会缺省为“webapp.root”

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<context-param>            <param-name>webAppRootKey</param-name>            <param-value> business.root </param-value>        </context-param>    <!—public-base应用路径  -->        <context-param>            <param-name>webAppRootKey</param-name>            <param-value> pubbase.root</param-value>        </context-param>

在web.xml中该Servlet的定义标记中，比如：

servlet范围内的参数，只能在servlet的init()方法中取得(或者通过注解配置在对应的类上：@WebServlet("/MyServlet")

System.out.println(this.getInitParameter("param1")=this.getServletConfig().getInitParameter(name));

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<servlet>      <servlet-name>TimeServlet</servlet-name>      <servlet-class>com.allanlxf.servlet.basic.TimeServlet</servlet-class>     <init-param>         <param-name>param1</param-name>         <param-value>avalible in servlet init()</param-value>     </init-param>     <load-on-startup>0</load-on-startup>//标记容器是否在启动的时候就加载这个servlet,执行init（）方法，初始化参数</servlet>

配置监听器：（启动Web容器时，自动装配ApplicationContext、log4j的配置信息。）

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<context-param>      <param-name>contextConfigLocation</param-name>      <param-value>/WEB-INF/spring-configuration/*.xml</param-value>  </context-param> <context-param>         <param-name>log4jConfigLocation</param-name>         <param-value>WEB-INF/log4j.properties</param-value>     </context-param>       <context-param>         <param-name>log4jRefreshInterval</param-name>         <param-value>6000</param-value>     </context-param>    <!-- Spring的log4j监听器 --> <listener>      <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>  </listener>  <listener>      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>  </listener>  <!-- 与CAS Single Sign Out Filter配合，注销登录信息  --> <listener>  <listener-class>com.yonyou.mcloud.cas.client.session.SingleSignOutHttpSessionListener</listener-class>  </listener>

配置过滤器：

Filter可认为是Servle的一种“加强版”，主要用于对用户请求request进行预处理，也可以对Response进行后处理，是个典型的处理链。使用Filter的完整流程是：Filter对用户请求进行预处理，接着将请求HttpServletRequest交给Servlet进行处理并生成响应，最后Filter再对服务器响应HttpServletResponse进行后处理。Filter与Servlet具有完全相同的生命周期，且Filter也可以通过<init-param>来配置初始化参数，获取Filter的初始化参数则使用FilterConfig的getInitParameter()。

换种说法，Servlet里有request和response两个对象，Filter能够在一个request到达Servlet之前预处理request，也可以在离开Servlet时处理response，Filter其实是一个Servlet链。以下是Filter的一些常见应用场合，创建一个过滤器，实现Filter接口。重新init(), doFilter(), destroy().

注解的方式配置：@WebFilter(filterName="FirstFilter",urlPatterns={"/index.jsp"},initParams={WWebInitParam(name="mood",value="awake")})

urlPatterns:哪些URL可以过滤，默认“/*”

initParams: 初始化哪些参数。

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<!--****************************过滤器配置*********************************-->   <!-- 字符集过滤器 -->   <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>forceEncoding</param-name>        <param-value>true</param-value>      </init-param>    </filter>    <!-- 单点登出过滤器 -->   <filter>      <filter-name>CAS Single Sign Out Filter</filter-name>      <filter-class>com.yonyou.mcloud.cas.client.session.SingleSignOutFilter</filter-class>    </filter>    <!-- 认证过滤器 -->   <filter>      <filter-name>CAS Authentication Filter</filter-name>  <filter-class>com.yonyou.mcloud.cas.client.authentication.ExpandAuthenticationFilter</filter-class>      <init-param>        <param-name>casServerLoginUrl</param-name>        <param-value>https://dev.yonyou.com:443/sso-server/login</param-value>      </init-param>      <init-param>        <!--这里的server是服务端的IP -->       <param-name>serverName</param-name>        <param-value>http://10.1.215.40:80</param-value>      </init-param>    </filter>    <!-- 验证ST/PT过滤器 -->   <filter>      <filter-name>CAS Validation Filter</filter-name>  <filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class>      <init-param>        <param-name>casServerUrlPrefix</param-name>        <param-value>https://dev.yonyou.com:443/sso-server</param-value>      </init-param>      <init-param>        <param-name>serverName</param-name>        <param-value>http://10.1.215.40:80</param-value>      </init-param>      <init-param>        <param-name>proxyCallbackUrl</param-name>        <param-value>https://dev.yonyou.com:443/business/proxyCallback</param-value>      </init-param>      <init-param>        <param-name>proxyReceptorUrl</param-name>        <param-value>/proxyCallback</param-value>      </init-param>      <init-param>        <param-name>proxyGrantingTicketStorageClass</param-name>  <param-value>com.yonyou.mcloud.cas.client.proxy.MemcachedBackedProxyGrantingTicketStorageImpl</param-value>      </init-param>      <!-- 解决中文问题 -->     <init-param>        <param-name>encoding</param-name>        <param-value>UTF-8</param-value>      </init-param>    </filter>    <filter>      <filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>      <filter-class>org.jasig.cas.client.util.HttpServletRequestWrapperFilter</filter-class>    </filter>    <filter>      <filter-name>CAS Assertion Thread Local Filter</filter-name>      <filter-class>org.jasig.cas.client.util.AssertionThreadLocalFilter</filter-class>    </filter>    <filter>      <filter-name>NoCache Filter</filter-name>      <filter-class>com.yonyou.mcloud.cas.client.authentication.NoCacheFilter</filter-class>    </filter>    <!--****************************映射关系配置********************************-->   <filter-mapping>      <filter-name>CharacterEncodingFilter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>NoCache Filter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>CAS Single Sign Out Filter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>CAS Validation Filter</filter-name>      <url-pattern>/proxyCallback</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>CAS Authentication Filter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>CAS Validation Filter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>    <filter-mapping>      <filter-name>CAS Assertion Thread Local Filter</filter-name>      <url-pattern>/*</url-pattern>    </filter-mapping>

配置失效时间：

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<session-config>      <session-timeout>120</session-timeout>   </session-config>

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<welcome-file-list>      <welcome-file>index.html</welcome-file>  </welcome-file-list></span>