Como tratar exceções em um arquivo xml?

<?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>teste</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <servlet> <description></description> <display-name>acao</display-name> <servlet-name>acao</servlet-name> <servlet-class>br.com.a.acao</servlet-class> </servlet> <servlet-mapping> <servlet-name>acao</servlet-name> <url-pattern>/acao</url-pattern> </servlet-mapping> <error-page> <error-code>404</error-code> <location>/erro.html</location> </error-page> <error-page> <exception-type>java.lang.Exception</exception-type> <location>/erro.html</location> </error-page> </web-app>

entao da linha 22 a 29 nao deveria ser redimencionado a pagina erro.html ao ocorrer uma exceção ou a aparecer um 404?

O arquivo erro.html existe?

O que está aparecendo?

sim ele existe.

29/01/2011 13:26:58 org.apache.tomcat.util.digester.SetPropertiesRule begin WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:sistema_web' did not find a matching property. 29/01/2011 13:26:58 org.apache.tomcat.util.digester.SetPropertiesRule begin WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:teste' did not find a matching property. 29/01/2011 13:26:58 org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Arquivos de programas\Java\jre6\bin;.;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\Arquivos de programas\Java\jre6\bin\client;C:\Arquivos de programas\Java\jre6\bin;c:\windows\system32;c:\windows;c:\windows\system32 \wbem;C:\Arquivos de programas\Java\jdk1.6.0_16/bin;C:\Arquivos de programas\MySQL\MySQL Server 5.1\bin 29/01/2011 13:26:58 org.apache.coyote.http11.Http11Protocol init INFO: Initializing Coyote HTTP/1.1 on http-8080 29/01/2011 13:26:58 org.apache.catalina.startup.Catalina load INFO: Initialization processed in 758 ms 29/01/2011 13:26:58 org.apache.catalina.core.StandardService start INFO: Starting service Catalina 29/01/2011 13:26:58 org.apache.catalina.core.StandardEngine start INFO: Starting Servlet Engine: Apache Tomcat/6.0.16 29/01/2011 13:26:59 org.apache.coyote.http11.Http11Protocol start INFO: Starting Coyote HTTP/1.1 on http-8080 29/01/2011 13:26:59 org.apache.jk.common.ChannelSocket init INFO: JK: ajp13 listening on /0.0.0.0:8009 29/01/2011 13:26:59 org.apache.jk.server.JkMain start INFO: Jk running ID=0 time=0/47 config=null 29/01/2011 13:26:59 org.apache.catalina.startup.Catalina start INFO: Server startup in 802 ms java.text.ParseException: Unparseable date: "" at java.text.DateFormat.parse(Unknown Source) at br.com.a.acao.service(acao.java:60) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Unknown Source) 29/01/2011 13:27:03 org.apache.catalina.core.StandardWrapperValve invoke SEVERE: Servlet.service() for servlet acao threw exception java.lang.NullPointerException at java.util.Calendar.setTime(Unknown Source) at br.com.a.acao.service(acao.java:66) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Unknown Source)

fecha que na pilha apareece a exceção que era para meu xml pegar.

ele mostra a pagina padrao de erro do apache e nao o meu erro.html ao se pegar uma exeção.