/*
* RHQ Management Platform
* Copyright (C) 2005-2010 Red Hat, Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.rhq.coregui.server.gwt;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.gwt.user.server.rpc.RPCRequest;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.rhq.core.domain.auth.Subject;
import org.rhq.core.util.exception.ThrowableUtil;
import org.rhq.enterprise.server.auth.SubjectManagerLocal;
import org.rhq.enterprise.server.util.HibernatePerformanceMonitor;
import org.rhq.enterprise.server.util.LookupUtil;
/**
* @author Greg Hinkle
* @author Joseph Marques
*/
public abstract class AbstractGWTServiceImpl extends RemoteServiceServlet {
private static final long serialVersionUID = 1L;
private Log log = LogFactory.getLog(this.getClass());
private ThreadLocal<Subject> sessionSubject = new ThreadLocal<Subject>();
private ThreadLocal<String> rpcMethod = new ThreadLocal<String>();
protected Subject getSessionSubject() {
return sessionSubject.get();
}
protected Log getLog() {
return log;
}
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
if (log.isTraceEnabled()) {
printHeaders(req);
}
boolean continueProcessing = true;
String sid = req.getHeader("RHQ-Session");
if (sid != null) {
SubjectManagerLocal subjectManager = LookupUtil.getSubjectManager();
try {
Subject subject = subjectManager.getSubjectBySessionId(Integer.parseInt(sid));
sessionSubject.set(subject);
} catch (Exception e) {
log.trace("Failed to validate request: sessionId was '" + sid + "', requestURL=" + req.getRequestURL());
continueProcessing = false;
}
} else {
log.debug("Failed to validate request: sessionId missing, requestURL=" + req.getRequestURL());
continueProcessing = false;
}
if (continueProcessing) {
// TODO: only execute this if the session lookup was successful, otherwise fail in some deterministic fashion
// alter callback handlers to capture expected failure and retry (at least once)
// to add resilience to gwt service calls
long id = HibernatePerformanceMonitor.get().start();
super.service(req, resp);
HibernatePerformanceMonitor.get().stop(id, "GWT:" + rpcMethod.get());
}
}
@Override
protected void onAfterRequestDeserialized(RPCRequest rpcRequest) {
super.onAfterRequestDeserialized(rpcRequest);
Method rpcMethod = rpcRequest.getMethod();
String className = rpcMethod.getDeclaringClass().getSimpleName();
String methodName = rpcMethod.getName();
this.rpcMethod.set(className + "." + methodName);
}
/**
* Our GWT Service implementations should call this whenever it needs to send an exception to the GWT client.
* @param t the server side exception that needs to be thrown
* @returns a RuntimeException that is the real exception that should be thrown to the GWT client
*/
protected RuntimeException getExceptionToThrowToClient(Throwable t) throws RuntimeException {
return getExceptionToThrowToClient(t, null);
}
/**
* Our GWT Service implementations should call this whenever it needs to send an exception to the GWT client.
* @param t the server side exception that needs to be thrown
* @param message an extra message to put in the returned exception
* @returns a RuntimeException that is the real exception that should be thrown to the GWT client
*/
protected RuntimeException getExceptionToThrowToClient(Throwable t, String message) throws RuntimeException {
// this id is so the user can correlate this exception in the server log with the client message in the browser
StringBuilder id = new StringBuilder("[");
id.append(System.currentTimeMillis());
if (message != null) {
id.append(" ").append(message);
}
id.append("] ");
// log the exception server-side
log.warn("Sending exception to client: " + id.toString(), t);
// cannot assume gwt client has our exception classes, only send the messages in a generic runtime exception
return new RuntimeException(id.toString() + ThrowableUtil.getAllMessages(t));
}
@SuppressWarnings("unchecked")
private void printHeaders(HttpServletRequest req) {
// TODO: figure out why SESSION_NAME header and other GWT-specific headers are missing occasionally
// seems to only happen on polling for recent alerts when there is no user activity for a few minutes
Enumeration<String> headerNames = req.getHeaderNames();
log.trace(req.getRequestURL().toString());
while (headerNames.hasMoreElements()) {
log.trace(" " + headerNames.nextElement());
}
}
}