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Tomcat example source code file (ErrorReportValve.java)

This example Tomcat source code file (ErrorReportValve.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

hr, http, illegalstateexception, io, ioexception, request, response, response, servlet, servletexception, string, string, stringbuffer, stringbuffer, stringmanager, throwable, throwable, valvebase

The Tomcat ErrorReportValve.java source code

 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *      http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.apache.catalina.valves;

import java.io.IOException;
import java.io.Writer;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;

import org.apache.catalina.Globals;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.util.RequestUtil;
import org.apache.catalina.util.ServerInfo;
import org.apache.catalina.util.StringManager;

 * <p>Implementation of a Valve that outputs HTML error pages.

* * <p>This Valve should be attached at the Host level, although it will work * if attached to a Context.</p> * * <p>HTML code from the Cocoon 2 project.

* * @author Remy Maucherat * @author Craig R. McClanahan * @author <a href="mailto:nicolaken@supereva.it">Nicola Ken Barozzi Aisa * @author <a href="mailto:stefano@apache.org">Stefano Mazzocchi * @author Yoav Shapira * @version $Revision: 543307 $ $Date: 2007-06-01 01:08:24 +0200 (ven., 01 juin 2007) $ */ public class ErrorReportValve extends ValveBase { // ----------------------------------------------------- Instance Variables /** * The descriptive information related to this implementation. */ private static final String info = "org.apache.catalina.valves.ErrorReportValve/1.0"; /** * The StringManager for this package. */ protected static StringManager sm = StringManager.getManager(Constants.Package); // ------------------------------------------------------------- Properties /** * Return descriptive information about this Valve implementation. */ public String getInfo() { return (info); } // --------------------------------------------------------- Public Methods /** * 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 */ 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) { ; } } // ------------------------------------------------------ Protected Methods /** * 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 */ 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>"); 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) { ; } } /** * Print out a partial servlet stack trace (truncating at the last * occurrence of javax.servlet.). */ 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(); } } </pre> <div id="after_source_code"> <h2>Other Tomcat examples (source code examples)</h2> <p>Here is a short list of links related to this Tomcat ErrorReportValve.java source code file:</p> <ul> <li><a href="/java/jwarehouse"><img src="/images/scw/find.png" border="0"> The search page</a></li> <li><a href="index.shtml"><img src="/images/scw/folder.png" border="0"> Other Tomcat source code examples at this package level</a></li> <li><a href="/java/jwarehouse/about.shtml"><img src="/images/scw/information.png" border="0"> Click here to learn more about this project</a></li> </ul> </div> </td> </tr> </table> </div> </div> <div id="whats_new"> <h2>new blog posts</h2> <div id="whats_new_list"> <ul> <li><a class="whats_new_link" href="/personal/stories/cruiser">Cruiser</a></li> <li><a class="whats_new_link" href="/personal/stories/old-man">Old Man</a></li> <li><a class="whats_new_link" href="/stories">Stories</a></li> <br/> <li><a class="whats_new_link" href="/scala/reverse-polish-notation-calculator-foldleft-scala-example">A Reverse Polish Notation calculator written with foldLeft in Scala</a></li> <li><a class="whats_new_link" href="/scala/scala-impure-annotation-functional-programming-pure-functions">An @impure annotation for Scala</a></li> <li><a class="whats_new_link" href="/personal/stories/bananas">Bananas</a></li> <br/> <li><a class="whats_new_link" href="/scala/scala-command-line-arguments-argot-passing-args-through-sbt">Processing Scala command-line arguments with Argot, and passing command-line arguments through SBT</a></li> <li><a class="whats_new_link" href="/scala/scala-type-examples-type-aliases-members">Scala type examples (type aliases and type members)</a></li> <li><a class="whats_new_link" href="/scala/how-configure-eclipse-scala-command-line-arguments-parameters">Setting a Scala application's command line parameters in Eclipse</a></li> <br/> <br/> </div> </ul> </div> <p> </p> <p align="center"><font color="#000000" size="2" face="Verdana,Arial">Copyright 1998-2014 Alvin Alexander, alvinalexander.com<br/> All Rights Reserved. <script type="text/javascript"> var _gaq = _gaq || []; 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