tomcat - javax.servlet.ServletException - 我怎样才能找到原因？

Question

我在我的网络应用程序中打开其中一个页面时遇到了一个非常奇怪的错误。该应用程序基于 Seam 2.2 构建，并在表示层中使用 JSF (RichFaces)。我在 Tomcat 6 上运行它。

在日志中一切看起来都很好——每个下一个 JSF 阶段都正常执行，在最后一个阶段之后，有一个请求开始处理 SEAM 调试页面的时刻...

这是我在调试页面上看到的堆栈跟踪(未记录任何内容):

请求处理期间的异常:由带有消息的 javax.servlet.ServletException 引起:“Servlet 执行引发异常”

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:313)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
pl.mgibowski.alterium.util.LoggingFilter.doFilter(LoggingFilter.java:18)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:465)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
java.lang.Thread.run(Thread.java:619)

没有任何原因的异常...

我试图用我的自定义过滤器(您可以在 strack 跟踪中看到的 LoggingFilter.java)捕获异常，使用以下代码:

try {
            filterChain.doFilter(servletRequest, servletResponse);
        }
        catch (Throwable e) {
            e.printStackTrace();
            System.out.println("Stack trace:");
            System.out.println(e.getStackTrace());
            System.out.println("Cause:");
            System.out.println(e.getCause());
        }

但它没有捕捉到任何东西，堆栈跟踪中的第 18 行是这一行:

filterChain.doFilter(servletRequest, servletResponse);

没有任何东西被 try block 捕获。

有人知道我怎样才能更接近真正的原因吗？

Answer 1

好的，我已经更改了我的过滤器和我的过滤器映射在 web.xml 中的应用顺序，现在我的过滤器正在捕获真正的异常。