001: /*
002: * $Header: /home/cvs/jakarta-tomcat-4.0/catalina/src/share/org/apache/catalina/valves/ErrorDispatcherValve.java,v 1.8 2001/12/02 22:19:26 remm Exp $
003: * $Revision: 1.8 $
004: * $Date: 2001/12/02 22:19:26 $
005: *
006: * ====================================================================
007: *
008: * The Apache Software License, Version 1.1
009: *
010: * Copyright (c) 1999-2001 The Apache Software Foundation. All rights
011: * reserved.
012: *
013: * Redistribution and use in source and binary forms, with or without
014: * modification, are permitted provided that the following conditions
015: * are met:
016: *
017: * 1. Redistributions of source code must retain the above copyright
018: * notice, this list of conditions and the following disclaimer.
019: *
020: * 2. Redistributions in binary form must reproduce the above copyright
021: * notice, this list of conditions and the following disclaimer in
022: * the documentation and/or other materials provided with the
023: * distribution.
024: *
025: * 3. The end-user documentation included with the redistribution, if
026: * any, must include the following acknowlegement:
027: * "This product includes software developed by the
028: * Apache Software Foundation (http://www.apache.org/)."
029: * Alternately, this acknowlegement may appear in the software itself,
030: * if and wherever such third-party acknowlegements normally appear.
031: *
032: * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
033: * Foundation" must not be used to endorse or promote products derived
034: * from this software without prior written permission. For written
035: * permission, please contact apache@apache.org.
036: *
037: * 5. Products derived from this software may not be called "Apache"
038: * nor may "Apache" appear in their names without prior written
039: * permission of the Apache Group.
040: *
041: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
042: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
043: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
044: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
045: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
046: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
047: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
048: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
049: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
050: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
051: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
052: * SUCH DAMAGE.
053: * ====================================================================
054: *
055: * This software consists of voluntary contributions made by many
056: * individuals on behalf of the Apache Software Foundation. For more
057: * information on the Apache Software Foundation, please see
058: * <http://www.apache.org/>.
059: *
060: * [Additional notices, if required by prior licensing conditions]
061: *
062: */
063:
064: package org.apache.catalina.valves;
065:
066: import java.io.IOException;
067: import java.util.ArrayList;
068: import java.util.Enumeration;
069: import java.util.Iterator;
070: import javax.servlet.RequestDispatcher;
071: import javax.servlet.ServletContext;
072: import javax.servlet.ServletException;
073: import javax.servlet.ServletRequest;
074: import javax.servlet.ServletResponse;
075: import javax.servlet.http.Cookie;
076: import javax.servlet.http.HttpServletRequest;
077: import javax.servlet.http.HttpServletResponse;
078: import org.apache.catalina.Container;
079: import org.apache.catalina.Context;
080: import org.apache.catalina.Globals;
081: import org.apache.catalina.HttpRequest;
082: import org.apache.catalina.HttpResponse;
083: import org.apache.catalina.Logger;
084: import org.apache.catalina.Request;
085: import org.apache.catalina.Response;
086: import org.apache.catalina.Valve;
087: import org.apache.catalina.ValveContext;
088: import org.apache.catalina.Wrapper;
089: import org.apache.catalina.deploy.ErrorPage;
090: import org.apache.catalina.util.RequestUtil;
091: import org.apache.catalina.util.StringManager;
092:
093: /**
094: * <p>Implementation of a Valve that handles the error dispatch (that is, will
095: * forward to the appropriate error page if necessary).</p>
096: *
097: * <p>This Valve should be attached at the Host level, although it will work
098: * if attached to a Context.</p>
099: *
100: * <p><b>WARNING</b>: This valve is necessary for Servlet API compliance.</p>
101: *
102: * @author Remy Maucherat
103: * @author Craig R. McClanahan
104: * @version $Revision: 1.8 $ $Date: 2001/12/02 22:19:26 $
105: */
106:
107: public class ErrorDispatcherValve extends ValveBase {
108:
109: // ----------------------------------------------------- Instance Variables
110:
111: /**
112: * The debugging detail level for this component.
113: */
114: protected int debug = 0;
115:
116: /**
117: * The descriptive information related to this implementation.
118: */
119: protected static final String info = "org.apache.catalina.valves.ErrorDispatcherValve/1.0";
120:
121: /**
122: * The StringManager for this package.
123: */
124: protected static StringManager sm = StringManager
125: .getManager(Constants.Package);
126:
127: // ------------------------------------------------------------- Properties
128:
129: /**
130: * Return descriptive information about this Valve implementation.
131: */
132: public String getInfo() {
133:
134: return (info);
135:
136: }
137:
138: // --------------------------------------------------------- Public Methods
139:
140: /**
141: * Invoke the next Valve in the sequence. When the invoke returns, check
142: * the response state, and output an error report is necessary.
143: *
144: * @param request The servlet request to be processed
145: * @param response The servlet response to be created
146: * @param context The valve context used to invoke the next valve
147: * in the current processing pipeline
148: *
149: * @exception IOException if an input/output error occurs
150: * @exception ServletException if a servlet error occurs
151: */
152: public void invoke(Request request, Response response,
153: ValveContext context) throws IOException, ServletException {
154:
155: // Perform the request
156: context.invokeNext(request, response);
157:
158: response.setSuspended(false);
159:
160: ServletRequest sreq = request.getRequest();
161: Throwable t = (Throwable) sreq
162: .getAttribute(Globals.EXCEPTION_ATTR);
163:
164: if (t != null) {
165: throwable(request, response, t);
166: } else {
167: status(request, response);
168: }
169:
170: }
171:
172: /**
173: * Return a String rendering of this object.
174: */
175: public String toString() {
176:
177: StringBuffer sb = new StringBuffer("ErrorDispatcherValve[");
178: sb.append(container.getName());
179: sb.append("]");
180: return (sb.toString());
181:
182: }
183:
184: // ------------------------------------------------------ Protected Methods
185:
186: /**
187: * Handle the specified Throwable encountered while processing
188: * the specified Request to produce the specified Response. Any
189: * exceptions that occur during generation of the exception report are
190: * logged and swallowed.
191: *
192: * @param request The request being processed
193: * @param response The response being generated
194: * @param exception The exception that occurred (which possibly wraps
195: * a root cause exception
196: */
197: protected void throwable(Request request, Response response,
198: Throwable throwable) {
199:
200: Context context = request.getContext();
201: if (context == null)
202: return;
203:
204: Throwable realError = throwable;
205: ErrorPage errorPage = findErrorPage(context, realError);
206: if ((errorPage == null)
207: && (realError instanceof ServletException)) {
208: realError = ((ServletException) realError).getRootCause();
209: if (realError != null)
210: errorPage = findErrorPage(context, realError);
211: else
212: realError = throwable;
213: }
214:
215: if (errorPage != null) {
216: response.setAppCommitted(false);
217: ServletRequest sreq = request.getRequest();
218: ServletResponse sresp = response.getResponse();
219: sreq.setAttribute(Globals.STATUS_CODE_ATTR, new Integer(
220: HttpServletResponse.SC_INTERNAL_SERVER_ERROR));
221: sreq.setAttribute(Globals.ERROR_MESSAGE_ATTR, throwable
222: .getMessage());
223: sreq.setAttribute(Globals.EXCEPTION_ATTR, throwable);
224: Wrapper wrapper = request.getWrapper();
225: if (wrapper != null)
226: sreq.setAttribute(Globals.SERVLET_NAME_ATTR, wrapper
227: .getName());
228: if (sreq instanceof HttpServletRequest)
229: sreq.setAttribute(Globals.EXCEPTION_PAGE_ATTR,
230: ((HttpServletRequest) sreq).getRequestURI());
231: sreq.setAttribute(Globals.EXCEPTION_TYPE_ATTR, throwable
232: .getClass());
233: if (custom(request, response, errorPage)) {
234: try {
235: sresp.flushBuffer();
236: } catch (IOException e) {
237: log("Exception Processing " + errorPage, e);
238: }
239: }
240: }
241:
242: }
243:
244: /**
245: * Handle the HTTP status code (and corresponding message) generated
246: * while processing the specified Request to produce the specified
247: * Response. Any exceptions that occur during generation of the error
248: * report are logged and swallowed.
249: *
250: * @param request The request being processed
251: * @param response The response being generated
252: */
253: protected void status(Request request, Response response) {
254:
255: // Do nothing on non-HTTP responses
256: if (!(response instanceof HttpResponse))
257: return;
258: HttpResponse hresponse = (HttpResponse) response;
259: if (!(response.getResponse() instanceof HttpServletResponse))
260: return;
261: int statusCode = hresponse.getStatus();
262: String message = RequestUtil.filter(hresponse.getMessage());
263: if (message == null)
264: message = "";
265:
266: // Handle a custom error page for this status code
267: Context context = request.getContext();
268: if (context == null)
269: return;
270:
271: ErrorPage errorPage = context.findErrorPage(statusCode);
272: if (errorPage != null) {
273: response.setAppCommitted(false);
274: ServletRequest sreq = request.getRequest();
275: ServletResponse sresp = response.getResponse();
276: sreq.setAttribute(Globals.STATUS_CODE_ATTR, new Integer(
277: statusCode));
278: sreq.setAttribute(Globals.ERROR_MESSAGE_ATTR, message);
279: Wrapper wrapper = request.getWrapper();
280: if (wrapper != null)
281: sreq.setAttribute(Globals.SERVLET_NAME_ATTR, wrapper
282: .getName());
283: if (sreq instanceof HttpServletRequest)
284: sreq.setAttribute(Globals.EXCEPTION_PAGE_ATTR,
285: ((HttpServletRequest) sreq).getRequestURI());
286: if (custom(request, response, errorPage)) {
287: try {
288: sresp.flushBuffer();
289: } catch (IOException e) {
290: log("Exception Processing " + errorPage, e);
291: }
292: }
293: }
294:
295: }
296:
297: /**
298: * Find and return the ErrorPage instance for the specified exception's
299: * class, or an ErrorPage instance for the closest superclass for which
300: * there is such a definition. If no associated ErrorPage instance is
301: * found, return <code>null</code>.
302: *
303: * @param context The Context in which to search
304: * @param exception The exception for which to find an ErrorPage
305: */
306: protected static ErrorPage findErrorPage(Context context,
307: Throwable exception) {
308:
309: if (exception == null)
310: return (null);
311: Class clazz = exception.getClass();
312: String name = clazz.getName();
313: while (!"java.lang.Object".equals(clazz)) {
314: ErrorPage errorPage = context.findErrorPage(name);
315: if (errorPage != null)
316: return (errorPage);
317: clazz = clazz.getSuperclass();
318: if (clazz == null)
319: break;
320: name = clazz.getName();
321: }
322: return (null);
323:
324: }
325:
326: /**
327: * Handle an HTTP status code or Java exception by forwarding control
328: * to the location included in the specified errorPage object. It is
329: * assumed that the caller has already recorded any request attributes
330: * that are to be forwarded to this page. Return <code>true</code> if
331: * we successfully utilized the specified error page location, or
332: * <code>false</code> if the default error report should be rendered.
333: *
334: * @param request The request being processed
335: * @param response The response being generated
336: * @param errorPage The errorPage directive we are obeying
337: */
338: protected boolean custom(Request request, Response response,
339: ErrorPage errorPage) {
340:
341: if (debug >= 1)
342: log("Processing " + errorPage);
343:
344: // Validate our current environment
345: if (!(request instanceof HttpRequest)) {
346: if (debug >= 1)
347: log(" Not processing an HTTP request --> default handling");
348: return (false); // NOTE - Nothing we can do generically
349: }
350: HttpServletRequest hreq = (HttpServletRequest) request
351: .getRequest();
352: if (!(response instanceof HttpResponse)) {
353: if (debug >= 1)
354: log("Not processing an HTTP response --> default handling");
355: return (false); // NOTE - Nothing we can do generically
356: }
357: HttpServletResponse hres = (HttpServletResponse) response
358: .getResponse();
359:
360: try {
361:
362: // Reset the response if possible (else IllegalStateException)
363: hres.reset();
364:
365: // Forward control to the specified location
366: ServletContext servletContext = request.getContext()
367: .getServletContext();
368: RequestDispatcher rd = servletContext
369: .getRequestDispatcher(errorPage.getLocation());
370: rd.forward(hreq, hres);
371:
372: // If we forward, the response is suspended again
373: response.setSuspended(false);
374:
375: // Indicate that we have successfully processed this custom page
376: return (true);
377:
378: } catch (Throwable t) {
379:
380: // Report our failure to process this custom page
381: log("Exception Processing " + errorPage, t);
382: return (false);
383:
384: }
385:
386: }
387:
388: /**
389: * Log a message on the Logger associated with our Container (if any).
390: *
391: * @param message Message to be logged
392: */
393: protected void log(String message) {
394:
395: Logger logger = container.getLogger();
396: if (logger != null)
397: logger.log(this .toString() + ": " + message);
398: else
399: System.out.println(this .toString() + ": " + message);
400:
401: }
402:
403: /**
404: * Log a message on the Logger associated with our Container (if any).
405: *
406: * @param message Message to be logged
407: * @param throwable Associated exception
408: */
409: protected void log(String message, Throwable throwable) {
410:
411: Logger logger = container.getLogger();
412: if (logger != null)
413: logger.log(this .toString() + ": " + message, throwable);
414: else {
415: System.out.println(this .toString() + ": " + message);
416: throwable.printStackTrace(System.out);
417: }
418:
419: }
420:
421: }
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