Servlet初始配置 监听器和过滤器
Posted shuchen007
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ServletContext:application范围内的参数
此所设定的参
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> |
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-list></span>
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