/*
* RHQ Management Platform
* Copyright (C) 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.client.util.rpc;
import java.util.HashSet;
import java.util.Set;
import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.rpc.impl.RemoteServiceProxy;
import com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.ResponseReader;
import com.google.gwt.user.client.rpc.impl.RpcStatsContext;
import com.google.gwt.user.client.rpc.impl.Serializer;
import org.rhq.coregui.client.UserSessionManager;
import org.rhq.coregui.client.util.Log;
/**
* A custom {@link RemoteServiceProxy} that injects additional management and monitoring functionality into the
* RPC lifecycle. Below are the list of extensions:
*
* <ul>
* <li>Conditionally sends requests based off of the client-side loggedIn state. Once the user's client-side session
* has expired, communication back to the server is halted by silently dropping requests. Obviously, for this to
* work, the methods that are used prior to being authenticated can not be wrapped with this proxy.</li>
* <li>Wrap the existing {@link RequestCallback} in a {@link TrackingRequestCallback}, which will provide 1) a
* fall-back mechanism for exceptions/errors that occur while the user is logged out, and 2) a notification
* mechanism to send the {@link RPCTracker} events which will tell the activityIndicator when to spin.</li>
* <li>Put the user's sessionId into the header of the request.</li>
*
* @author Joseph Marques
*/
public class TrackingRemoteServiceProxy extends RemoteServiceProxy {
/** Don't block methods used during the login or logout process. Declare the exceptions here. */
private static final Set<String> bypassMethods = new HashSet<String>();
static {
bypassMethods.add("SubjectGWTService_Proxy.findSubjectsByCriteria");
bypassMethods.add("SubjectGWTService_Proxy.processSubjectForLdap");
bypassMethods.add("SubjectGWTService_Proxy.logout");
}
public TrackingRemoteServiceProxy(String moduleBaseURL, String remoteServiceRelativePath,
String serializationPolicyName, Serializer serializer) {
super(moduleBaseURL, remoteServiceRelativePath, serializationPolicyName, serializer);
}
/*
* This method is currently not called by the RPC framework. When it is, we can remove the sessionId
* logic from the GWTServiceLookup class.
*
* For background information, please see http://code.google.com/p/google-web-toolkit/issues/detail?id=5668
*/
@Override
protected <T> RequestBuilder doPrepareRequestBuilder(ResponseReader responseReader, String methodName,
RpcStatsContext statsContext, String requestData, AsyncCallback<T> callback) {
RequestBuilder rb = super.doPrepareRequestBuilder(responseReader, methodName, statsContext, requestData,
callback);
String sessionId = UserSessionManager.getSessionId();
if (sessionId != null) {
if (Log.isDebugEnabled()) {
Log.debug("SessionRpcRequestBuilder is adding sessionId to request for (" + methodName + ")");
}
rb.setHeader(UserSessionManager.SESSION_NAME, sessionId);
} else {
Log.error("SessionRpcRequestBuilder missing sessionId for request (" + methodName + ")");
}
return rb;
}
// TODO: add handled to capture timeout failure and retry (at least once) to add resilience to GWT service calls?
@Override
protected <T> RequestCallback doCreateRequestCallback(ResponseReader responseReader, String methodName,
RpcStatsContext statsContext, AsyncCallback<T> callback) {
RequestCallback original = super.doCreateRequestCallback(responseReader, methodName, statsContext, callback);
TrackingRequestCallback trackingCallback = new TrackingRequestCallback(statsContext.getRequestId(), methodName,
original);
RPCTracker.getInstance().register(trackingCallback);
return trackingCallback;
}
@Override
protected <T> Request doInvoke(ResponseReader responseReader, String methodName, RpcStatsContext statsContext,
String requestData, AsyncCallback<T> callback) {
if (Log.isDebugEnabled()) {
Log.debug("RPC method invocation: " + methodName);
}
if (bypassMethods.contains(methodName) || !UserSessionManager.isLoggedOut()) {
return super.doInvoke(responseReader, methodName, statsContext, requestData, callback);
}
return null;
}
}