public String getInfo() 
{
    // ------------------------------------------------------------- Properties
        return (info);
}

Return descriptive information about this Valve implementation.

 protected String getPartialServletStackTrace(Throwable t) 
{
        StringBuffer trace = new StringBuffer();
        trace.append(t.toString()).append('\n");
        StackTraceElement[] elements = t.getStackTrace();
        int pos = elements.length;
        for (int i = 0; i <  elements.length; i++) {
            if ((elements[i].getClassName().startsWith
                 ("org.apache.catalina.core.ApplicationFilterChain"))
                && (elements[i].getMethodName().equals("internalDoFilter"))) {
                pos = i;
            }
        }
        for (int i = 0; i <  pos; i++) {
            if (!(elements[i].getClassName().startsWith
                  ("org.apache.catalina.core."))) {
                trace.append('\t").append(elements[i].toString()).append('\n");
            }
        }
        return trace.toString();
}

Print out a partial servlet stack trace (truncating at the last occurrence of javax.servlet.).

 public  void invoke(Request request,
    Response response) throws IOException, ServletException 
{
        // Perform the request
        getNext().invoke(request, response);
        Throwable throwable =
            (Throwable) request.getAttribute(Globals.EXCEPTION_ATTR);
        if (response.isCommitted()) {
            return;
        }
        if (throwable != null) {
            // The response is an error
            response.setError();
            // Reset the response (if possible)
            try {
                response.reset();
            } catch (IllegalStateException e) {
                ;
            }
            response.sendError
                (HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
        response.setSuspended(false);
        try {
            report(request, response, throwable);
        } catch (Throwable tt) {
            ;
        }
}

Invoke the next Valve in the sequence. When the invoke returns, check the response state, and output an error report is necessary.

 protected  void report(Request request,
    Response response,
    Throwable throwable) 
{
        // Do nothing on non-HTTP responses
        int statusCode = response.getStatus();
        // Do nothing on a 1xx, 2xx and 3xx status
        // Do nothing if anything has been written already
        if ((statusCode <  400) || (response.getContentCount()  > 0))
            return;
        String message = RequestUtil.filter(response.getMessage());
        if (message == null)
            message = "";
        // Do nothing if there is no report for the specified status code
        String report = null;
        try {
            report = sm.getString("http." + statusCode, message);
        } catch (Throwable t) {
            ;
        }
        if (report == null)
            return;
        StringBuffer sb = new StringBuffer();
        sb.append("< html >< head >< title >");
        sb.append(ServerInfo.getServerInfo()).append(" - ");
        sb.append(sm.getString("errorReportValve.errorReport"));
        sb.append("< /title >");
        sb.append("< style >< !--");
        sb.append(org.apache.catalina.util.TomcatCSS.TOMCAT_CSS);
        sb.append("-- >< /style > ");
        sb.append("< /head >< body >");
        sb.append("< h1 >");
        sb.append(sm.getString("errorReportValve.statusHeader",
                               "" + statusCode, message)).append("< /h1 >");
        sb.append("< HR size=\"1\" noshade=\"noshade\" >");
        sb.append("< p >< b >type< /b > ");
        if (throwable != null) {
            sb.append(sm.getString("errorReportValve.exceptionReport"));
        } else {
            sb.append(sm.getString("errorReportValve.statusReport"));
        }
        sb.append("< /p >");
        sb.append("< p >< b >");
        sb.append(sm.getString("errorReportValve.message"));
        sb.append("< /b > < u >");
        sb.append(message).append("< /u >< /p >");
        sb.append("< p >< b >");
        sb.append(sm.getString("errorReportValve.description"));
        sb.append("< /b > < u >");
        sb.append(report);
        sb.append("< /u >< /p >");
        if (throwable != null) {
            String stackTrace = getPartialServletStackTrace(throwable);
            sb.append("< p >< b >");
            sb.append(sm.getString("errorReportValve.exception"));
            sb.append("< /b > < pre >");
            sb.append(RequestUtil.filter(stackTrace));
            sb.append("< /pre >< /p >");
            int loops = 0;
            Throwable rootCause = throwable.getCause();
            while (rootCause != null && (loops <  10)) {
                stackTrace = getPartialServletStackTrace(rootCause);
                sb.append("< p >< b >");
                sb.append(sm.getString("errorReportValve.rootCause"));
                sb.append("< /b > < pre >");
                sb.append(RequestUtil.filter(stackTrace));
                sb.append("< /pre >< /p >");
                // In case root cause is somehow heavily nested
                rootCause = rootCause.getCause();
                loops++;
            }
            sb.append("< p >< b >");
            sb.append(sm.getString("errorReportValve.note"));
            sb.append("< /b > < u >");
            sb.append(sm.getString("errorReportValve.rootCauseInLogs",
                                   ServerInfo.getServerInfo()));
            sb.append("< /u >< /p >");
        }
        sb.append("< HR size=\"1\" noshade=\"noshade\" >");
        sb.append("< h3 >").append(ServerInfo.getServerInfo()).append("< /h3 >");
        sb.append("< /body >< /html >");
        try {
            try {
                response.setContentType("text/html");
                response.setCharacterEncoding("utf-8");
            } catch (Throwable t) {
                if (container.getLogger().isDebugEnabled())
                    container.getLogger().debug("status.setContentType", t);
            }
            Writer writer = response.getReporter();
            if (writer != null) {
                // If writer is null, it's an indication that the response has
                // been hard committed already, which should never happen
                writer.write(sb.toString());
            }
        } catch (IOException e) {
            ;
        } catch (IllegalStateException e) {
            ;
        }
}

Prints out an error report.