/*
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.catalina.core;
import java.io.IOException;
import javax.servlet.DispatcherType;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;
import org.apache.catalina.Context;
import org.apache.catalina.Globals;
import org.apache.catalina.Wrapper;
import org.apache.catalina.comet.CometEvent;
import org.apache.catalina.connector.ClientAbortException;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.valves.ValveBase;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.descriptor.web.ErrorPage;
import org.apache.tomcat.util.res.StringManager;
/**
* Valve that implements the default basic behavior for the
* <code>StandardHost</code> container implementation.
* <p>
* <b>USAGE CONSTRAINT</b>: This implementation is likely to be useful only
* when processing HTTP requests.
*
* @author Craig R. McClanahan
* @author Remy Maucherat
*/
final class StandardHostValve extends ValveBase {
private static final Log log = LogFactory.getLog(StandardHostValve.class);
// Saves a call to getClassLoader() on very request. Under high load these
// calls took just long enough to appear as a hot spot (although a very
// minor one) in a profiler.
private static final ClassLoader MY_CLASSLOADER =
StandardHostValve.class.getClassLoader();
protected static final boolean STRICT_SERVLET_COMPLIANCE;
protected static final boolean ACCESS_SESSION;
static {
STRICT_SERVLET_COMPLIANCE = Globals.STRICT_SERVLET_COMPLIANCE;
String accessSession = System.getProperty(
"org.apache.catalina.core.StandardHostValve.ACCESS_SESSION");
if (accessSession == null) {
ACCESS_SESSION = STRICT_SERVLET_COMPLIANCE;
} else {
ACCESS_SESSION =
Boolean.valueOf(accessSession).booleanValue();
}
}
//------------------------------------------------------ Constructor
public StandardHostValve() {
super(true);
}
// ----------------------------------------------------- Instance Variables
/**
* The string manager for this package.
*/
private static final StringManager sm =
StringManager.getManager(Constants.Package);
// --------------------------------------------------------- Public Methods
/**
* Select the appropriate child Context to process this request,
* based on the specified request URI. If no matching Context can
* be found, return an appropriate HTTP error.
*
* @param request Request to be processed
* @param response Response to be produced
*
* @exception IOException if an input/output error occurred
* @exception ServletException if a servlet error occurred
*/
@Override
public final void invoke(Request request, Response response)
throws IOException, ServletException {
// Select the Context to be used for this Request
Context context = request.getContext();
if (context == null) {
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
sm.getString("standardHost.noContext"));
return;
}
if (request.isAsyncSupported()) {
request.setAsyncSupported(context.getPipeline().isAsyncSupported());
}
boolean asyncAtStart = request.isAsync();
boolean asyncDispatching = request.isAsyncDispatching();
// An async error page may dispatch to another resource. This flag helps
// ensure an infinite error handling loop is not entered
boolean errorAtStart = response.isError();
try {
context.bind(Globals.IS_SECURITY_ENABLED, MY_CLASSLOADER);
if (!asyncAtStart && !context.fireRequestInitEvent(request)) {
// Don't fire listeners during async processing (the listener
// fired for the request that called startAsync()).
// If a request init listener throws an exception, the request
// is aborted.
return;
}
// Ask this Context to process this request
try {
if (!asyncAtStart || asyncDispatching) {
context.getPipeline().getFirst().invoke(request, response);
} else {
if (!errorAtStart) {
throw new IllegalStateException(sm.getString("standardHost.asyncStateError"));
}
}
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
if (errorAtStart) {
container.getLogger().error("Exception Processing " +
request.getRequestURI(), t);
} else {
request.setAttribute(RequestDispatcher.ERROR_EXCEPTION, t);
throwable(request, response, t);
}
}
Throwable t = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
// If the request was async at the start and an error occurred
// then the async error handling will kick-in and that will fire
// the request destroyed event *after* the error handling has
// taken place.
if (!(request.isAsync() || (asyncAtStart && t != null))) {
// Protect against NPEs if context was destroyed during a
// long running request.
if (context.getState().isAvailable()) {
if (!errorAtStart) {
// Error page processing
response.setSuspended(false);
if (t != null) {
throwable(request, response, t);
} else {
status(request, response);
}
}
context.fireRequestDestroyEvent(request);
}
}
} finally {
// Access a session (if present) to update last accessed time, based
// on a strict interpretation of the specification
if (ACCESS_SESSION) {
request.getSession(false);
}
context.unbind(Globals.IS_SECURITY_ENABLED, MY_CLASSLOADER);
}
}
/**
* Process Comet event.
*
* @param request Request to be processed
* @param response Response to be produced
* @param event the event
*
* @exception IOException if an input/output error occurred
* @exception ServletException if a servlet error occurred
*/
@Override
public final void event(Request request, Response response, CometEvent event)
throws IOException, ServletException {
// Select the Context to be used for this Request
Context context = request.getContext();
context.bind(false, MY_CLASSLOADER);
// Ask this Context to process this request
context.getPipeline().getFirst().event(request, response, event);
// Error page processing
response.setSuspended(false);
Throwable t = (Throwable) request.getAttribute(
RequestDispatcher.ERROR_EXCEPTION);
if (t != null) {
throwable(request, response, t);
} else {
status(request, response);
}
// Access a session (if present) to update last accessed time, based on a
// strict interpretation of the specification
if (ACCESS_SESSION) {
request.getSession(false);
}
// Restore the context classloader
context.unbind(false, MY_CLASSLOADER);
}
// -------------------------------------------------------- Private Methods
/**
* Handle the HTTP status code (and corresponding message) generated
* while processing the specified Request to produce the specified
* Response. Any exceptions that occur during generation of the error
* report are logged and swallowed.
*
* @param request The request being processed
* @param response The response being generated
*/
private void status(Request request, Response response) {
int statusCode = response.getStatus();
// Handle a custom error page for this status code
Context context = request.getContext();
if (context == null) {
return;
}
/* Only look for error pages when isError() is set.
* isError() is set when response.sendError() is invoked. This
* allows custom error pages without relying on default from
* web.xml.
*/
if (!response.isError()) {
return;
}
ErrorPage errorPage = context.findErrorPage(statusCode);
if (errorPage == null) {
// Look for a default error page
errorPage = context.findErrorPage(0);
}
if (errorPage != null && response.setErrorReported()) {
response.setAppCommitted(false);
request.setAttribute(RequestDispatcher.ERROR_STATUS_CODE,
Integer.valueOf(statusCode));
String message = response.getMessage();
if (message == null) {
message = "";
}
request.setAttribute(RequestDispatcher.ERROR_MESSAGE, message);
request.setAttribute(Globals.DISPATCHER_REQUEST_PATH_ATTR,
errorPage.getLocation());
request.setAttribute(Globals.DISPATCHER_TYPE_ATTR,
DispatcherType.ERROR);
Wrapper wrapper = request.getWrapper();
if (wrapper != null) {
request.setAttribute(RequestDispatcher.ERROR_SERVLET_NAME,
wrapper.getName());
}
request.setAttribute(RequestDispatcher.ERROR_REQUEST_URI,
request.getRequestURI());
if (custom(request, response, errorPage)) {
try {
response.finishResponse();
} catch (ClientAbortException e) {
// Ignore
} catch (IOException e) {
container.getLogger().warn("Exception Processing " + errorPage, e);
}
}
}
}
/**
* Handle the specified Throwable encountered while processing
* the specified Request to produce the specified Response. Any
* exceptions that occur during generation of the exception report are
* logged and swallowed.
*
* @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 throwable(Request request, Response response,
Throwable throwable) {
Context context = request.getContext();
if (context == null) {
return;
}
Throwable realError = throwable;
if (realError instanceof ServletException) {
realError = ((ServletException) realError).getRootCause();
if (realError == null) {
realError = throwable;
}
}
// If this is an aborted request from a client just log it and return
if (realError instanceof ClientAbortException ) {
if (log.isDebugEnabled()) {
log.debug
(sm.getString("standardHost.clientAbort",
realError.getCause().getMessage()));
}
return;
}
ErrorPage errorPage = findErrorPage(context, throwable);
if ((errorPage == null) && (realError != throwable)) {
errorPage = findErrorPage(context, realError);
}
if (errorPage != null) {
if (response.setErrorReported()) {
response.setAppCommitted(false);
request.setAttribute(Globals.DISPATCHER_REQUEST_PATH_ATTR,
errorPage.getLocation());
request.setAttribute(Globals.DISPATCHER_TYPE_ATTR,
DispatcherType.ERROR);
request.setAttribute(RequestDispatcher.ERROR_STATUS_CODE,
new Integer(HttpServletResponse.SC_INTERNAL_SERVER_ERROR));
request.setAttribute(RequestDispatcher.ERROR_MESSAGE,
throwable.getMessage());
request.setAttribute(RequestDispatcher.ERROR_EXCEPTION,
realError);
Wrapper wrapper = request.getWrapper();
if (wrapper != null) {
request.setAttribute(RequestDispatcher.ERROR_SERVLET_NAME,
wrapper.getName());
}
request.setAttribute(RequestDispatcher.ERROR_REQUEST_URI,
request.getRequestURI());
request.setAttribute(RequestDispatcher.ERROR_EXCEPTION_TYPE,
realError.getClass());
if (custom(request, response, errorPage)) {
try {
response.finishResponse();
} catch (IOException e) {
container.getLogger().warn("Exception Processing " + errorPage, e);
}
}
}
} else {
// A custom error-page has not been defined for the exception
// that was thrown during request processing. Check if an
// error-page for error code 500 was specified and if so,
// send that page back as the response.
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
// The response is an error
response.setError();
status(request, response);
}
}
/**
* Handle an HTTP status code or Java exception by forwarding control
* to the location included in the specified errorPage object. It is
* assumed that the caller has already recorded any request attributes
* that are to be forwarded to this page. Return <code>true</code> if
* we successfully utilized the specified error page location, or
* <code>false</code> if the default error report should be rendered.
*
* @param request The request being processed
* @param response The response being generated
* @param errorPage The errorPage directive we are obeying
*/
private boolean custom(Request request, Response response,
ErrorPage errorPage) {
if (container.getLogger().isDebugEnabled()) {
container.getLogger().debug("Processing " + errorPage);
}
try {
// Forward control to the specified location
ServletContext servletContext =
request.getContext().getServletContext();
RequestDispatcher rd =
servletContext.getRequestDispatcher(errorPage.getLocation());
if (response.isCommitted()) {
// Response is committed - including the error page is the
// best we can do
rd.include(request.getRequest(), response.getResponse());
} else {
// Reset the response (keeping the real error code and message)
response.resetBuffer(true);
response.setContentLength(-1);
rd.forward(request.getRequest(), response.getResponse());
// If we forward, the response is suspended again
response.setSuspended(false);
}
// Indicate that we have successfully processed this custom page
return (true);
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
// Report our failure to process this custom page
container.getLogger().error("Exception Processing " + errorPage, t);
return (false);
}
}
/**
* Find and return the ErrorPage instance for the specified exception's
* class, or an ErrorPage instance for the closest superclass for which
* there is such a definition. If no associated ErrorPage instance is
* found, return <code>null</code>.
*
* @param context The Context in which to search
* @param exception The exception for which to find an ErrorPage
*/
private static ErrorPage findErrorPage
(Context context, Throwable exception) {
if (exception == null) {
return (null);
}
Class<?> clazz = exception.getClass();
String name = clazz.getName();
while (!Object.class.equals(clazz)) {
ErrorPage errorPage = context.findErrorPage(name);
if (errorPage != null) {
return (errorPage);
}
clazz = clazz.getSuperclass();
if (clazz == null) {
break;
}
name = clazz.getName();
}
return (null);
}
}