web.xml 中的listener、 filter、servlet 加載順序及其詳解

2019-11-11 05:13:00

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供稿：網(wǎng)友

原文：http://www.cnblogs.com/JesseV/archive/2009/11/17/1605015.html

在項(xiàng)目中總會(huì)遇到一些關(guān)于加載的優(yōu)先級問題，近期也同樣遇到過類似的，所以自己查找資料總結(jié)了下，下面有些是</welcome-file> <welcome-file>index.htm</welcome-file> </welcome-file-list> 11、配置錯(cuò)誤頁面一、通過錯(cuò)誤碼來配置error-page <error-page> <error-code>404</error-code> <location>/NotFound.jsp</location> </error-page> 上面配置了當(dāng)系統(tǒng)發(fā)生404錯(cuò)誤時(shí)，跳轉(zhuǎn)到錯(cuò)誤處理頁面NotFound.jsp。二、通過異常的類型配置error-page <error-page> <exception-type>java.lang.NullException</exception-type> <location>/error.jsp</location> </error-page> 上面配置了當(dāng)系統(tǒng)發(fā)生java.lang.NullException（即空指針異常）時(shí)，跳轉(zhuǎn)到錯(cuò)誤處理頁面error.jsp 12、TLD配置 <taglib> <taglib-uri>http://jakarta.apache.org/tomcat/debug-taglib</taglib-uri> <taglib-location>/WEB-INF/jsp/debug-taglib.tld</taglib-location> </taglib> 如果MyEclipse一直在報(bào)錯(cuò),應(yīng)該把<taglib> 放到 <jsp-config>中 <jsp-config> <taglib> <taglib-uri>http://jakarta.apache.org/tomcat/debug-taglib</taglib-uri> <taglib-location>/WEB-INF/pager-taglib.tld</taglib-location> </taglib> </jsp-config> 13、資源管理對象配置 <resource-env-ref> <resource-env-ref-name>jms/StockQueue</resource-env-ref-name> </resource-env-ref> 14、資源工廠配置 <resource-ref> <res-ref-name>mail/session</res-ref-name> <res-type>javax.mail.Session</res-type> <res-auth>Container</res-auth> </resource-ref> 配置數(shù)據(jù)庫連接池就可在此配置： <resource-ref> <description>JNDI JDBC DataSource of shop</description> <res-ref-name>jdbc/sample_db</res-ref-name> <res-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> </resource-ref> 15、安全限制配置 <security-constraint> <display-name>Example Security Constraint</display-name> <web-resource-collection> <web-resource-name>PRotected Area</web-resource-name> <url-pattern>/jsp/security/protected/*</url-pattern> <http-method>DELETE</http-method> <http-method>GET</http-method> <http-method>POST</http-method> <http-method>PUT</http-method> </web-resource-collection> <auth-constraint> <role-name>tomcat</role-name> <role-name>role1</role-name> </auth-constraint> </security-constraint> 16、登陸驗(yàn)證配置 <login-config> <auth-method>FORM</auth-method> <realm-name>Example-Based Authentiation Area</realm-name> <form-login-config> <form-login-page>/jsp/security/protected/login.jsp</form-login-page> <form-error-page>/jsp/security/protected/error.jsp</form-error-page> </form-login-config> </login-config> 17、安全角色：security-role元素給出安全角色的一個(gè)列表，這些角色將出現(xiàn)在servlet元素內(nèi)的security-role-ref元素的role-name子元素中。分別地聲明角色可使高級IDE處理安全信息更為容易。 <security-role> <role-name>tomcat</role-name> </security-role> 18、Web環(huán)境參數(shù)：env-entry元素聲明Web應(yīng)用的環(huán)境項(xiàng) <env-entry> <env-entry-name>minExemptions</env-entry-name> <env-entry-value>1</env-entry-value> <env-entry-type>java.lang.Integer</env-entry-type> </env-entry> 19、EJB 聲明 <ejb-ref> <description>Example EJB reference</decription> <ejb-ref-name>ejb/Account</ejb-ref-name> <ejb-ref-type>Entity</ejb-ref-type> <home>com.mycompany.mypackage.AccountHome</home> <remote>com.mycompany.mypackage.Account</remote> </ejb-ref> 20、本地EJB聲明 <ejb-local-ref> <description>Example Loacal EJB reference</decription> <ejb-ref-name>ejb/ProcessOrder</ejb-ref-name> <ejb-ref-type>Session</ejb-ref-type> <local-home>com.mycompany.mypackage.ProcessOrderHome</local-home> <local>com.mycompany.mypackage.ProcessOrder</local> </ejb-local-ref> 21、配置DWR <servlet> <servlet-name>dwr-invoker</servlet-name> <servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>dwr-invoker</servlet-name> <url-pattern>/dwr/*</url-pattern> </servlet-mapping> 22、配置Struts <display-name>Struts Blank application</display-name> <servlet> <servlet-name>action</servlet-name> <servlet-class> org.apache.struts.action.ActionServlet </servlet-class> <init-param> <param-name>detail</param-name> <param-value>2</param-value> </init-param> <init-param> <param-name>debug</param-name> <param-value>2</param-value> </init-param> <init-param> <param-name>config</param-name> <param-value>/WEB-INF/struts-config.xml</param-value> </init-param> <init-param> <param-name>application</param-name> <param-value>ApplicationResources</param-value> </init-param> <load-on-startup>2</load-on-startup> </servlet> <servlet-mapping> <servlet-name>action</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list>  <taglib> <taglib-uri>struts-bean</taglib-uri> <taglib-location>/WEB-INF/tld/struts-bean.tld</taglib-location> </taglib> <taglib> <taglib-uri>struts-html</taglib-uri> <taglib-location>/WEB-INF/tld/struts-html.tld</taglib-location> </taglib> <taglib> <taglib-uri>struts-nested</taglib-uri> <taglib-location>/WEB-INF/tld/struts-nested.tld</taglib-location> </taglib> <taglib> <taglib-uri>struts-logic</taglib-uri> <taglib-location>/WEB-INF/tld/struts-logic.tld</taglib-location> </taglib> <taglib> <taglib-uri>struts-tiles</taglib-uri> <taglib-location>/WEB-INF/tld/struts-tiles.tld</taglib-location> </taglib> 23、配置Spring（基本上都是在Struts中配置的）  <context-param> <param-name>contextConfigLocation</param-name> <param-value>  /WEB-INF/applicationContext.xml, /WEB-INF/action-servlet.xml </param-value> </context-param>  <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <listener> <listener-class> org.springframework.web.context.request.RequestContextListener </listener-class> </listener>