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ErrorReportValve.javaAPI DocApache Tomcat 6.0.149818Fri Jul 20 04:20:30 BST 2007org.apache.catalina.valves

ErrorReportValve

public class ErrorReportValve extends ValveBase

Implementation of a Valve that outputs HTML error pages.

This Valve should be attached at the Host level, although it will work if attached to a Context.

HTML code from the Cocoon 2 project.

author
Remy Maucherat
author
Craig R. McClanahan
author
Nicola Ken Barozzi Aisa
author
Stefano Mazzocchi
author
Yoav Shapira
version
$Revision: 543307 $ $Date: 2007-06-01 01:08:24 +0200 (ven., 01 juin 2007) $

Fields Summary
private static final String
info
The descriptive information related to this implementation.
protected static org.apache.catalina.util.StringManager
sm
The StringManager for this package.
Constructors Summary
Methods Summary
public java.lang.StringgetInfo()
Return descriptive information about this Valve implementation.



    // ------------------------------------------------------------- Properties


                
       

        return (info);
protected java.lang.StringgetPartialServletStackTrace(java.lang.Throwable t)
Print out a partial servlet stack trace (truncating at the last occurrence of javax.servlet.).

        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();
public voidinvoke(org.apache.catalina.connector.Request request, org.apache.catalina.connector.Response response)
Invoke the next Valve in the sequence. When the invoke returns, check the response state, and output an error report is necessary.

param
request The servlet request to be processed
param
response The servlet response to be created
exception
IOException if an input/output error occurs
exception
ServletException if a servlet error occurs


        // 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) {
            ;
        }
protected voidreport(org.apache.catalina.connector.Request request, org.apache.catalina.connector.Response response, java.lang.Throwable throwable)
Prints out an error report.

param
request The request being processed
param
response The response being generated
param
throwable The exception that occurred (which possibly wraps a root cause exception


        // 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) {
            ;
        }