flex.messaging.endpoints.StreamingAMFEndpoint Maven / Gradle / Ivy
/*
* 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 flex.messaging.endpoints;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import flex.management.runtime.messaging.endpoints.StreamingAMFEndpointControl;
import flex.messaging.MessageBroker;
import flex.messaging.endpoints.amf.AMFFilter;
import flex.messaging.endpoints.amf.BatchProcessFilter;
import flex.messaging.endpoints.amf.LegacyFilter;
import flex.messaging.endpoints.amf.MessageBrokerFilter;
import flex.messaging.endpoints.amf.SerializationFilter;
import flex.messaging.endpoints.amf.SessionFilter;
import flex.messaging.io.MessageIOConstants;
import flex.messaging.io.TypeMarshallingContext;
import flex.messaging.io.amf.Amf3Output;
import flex.messaging.log.Log;
import flex.messaging.log.LogCategories;
import flex.messaging.messages.Message;
/**
* Extension to the AMFEndpoint to support streaming HTTP connections to connected
* clients.
* Each streaming connection managed by this endpoint consumes one of the request
* handler threads provided by the servlet container, so it is not highly scalable
* but offers performance advantages over client polling for clients receiving a steady,
* rapid stream of pushed messages.
* This endpoint does not support polling clients and will fault any poll requests
* that are received. To support polling clients use AMFEndpoint instead.
*/
public class StreamingAMFEndpoint extends BaseStreamingHTTPEndpoint
{
//--------------------------------------------------------------------------
//
// Public Static Constants
//
//--------------------------------------------------------------------------
/**
* The log category for this endpoint.
*/
public static final String LOG_CATEGORY = LogCategories.ENDPOINT_STREAMING_AMF;
//--------------------------------------------------------------------------
//
// Private Static Constants
//
//--------------------------------------------------------------------------
//--------------------------------------------------------------------------
//
// Constructors
//
//--------------------------------------------------------------------------
/**
* Constructs an unmanaged StreamingAMFEndpoint.
*/
public StreamingAMFEndpoint()
{
this(false);
}
/**
* Constructs a StreamingAMFEndpoint with the indicated management.
*
* @param enableManagement true if the StreamingAMFEndpoint
* is manageable; false otherwise.
*/
public StreamingAMFEndpoint(boolean enableManagement)
{
super(enableManagement);
}
//--------------------------------------------------------------------------
//
// Protected Methods
//
//--------------------------------------------------------------------------
/**
* Create the gateway filters that transform action requests
* and responses.
*/
@Override protected AMFFilter createFilterChain()
{
AMFFilter serializationFilter = new SerializationFilter(getLogCategory());
AMFFilter batchFilter = new BatchProcessFilter();
AMFFilter sessionFilter = sessionRewritingEnabled? new SessionFilter() : null;
AMFFilter envelopeFilter = new LegacyFilter(this);
AMFFilter messageBrokerFilter = new MessageBrokerFilter(this);
serializationFilter.setNext(batchFilter);
if (sessionFilter != null)
{
batchFilter.setNext(sessionFilter);
sessionFilter.setNext(envelopeFilter);
}
else
{
batchFilter.setNext(envelopeFilter);
}
envelopeFilter.setNext(messageBrokerFilter);
return serializationFilter;
}
/**
* Returns MessageIOConstants.AMF_CONTENT_TYPE.
*/
@Override protected String getResponseContentType()
{
return MessageIOConstants.AMF_CONTENT_TYPE;
}
/**
* Returns the log category of the endpoint.
*
* @return The log category of the endpoint.
*/
@Override protected String getLogCategory()
{
return LOG_CATEGORY;
}
/**
* Used internally for performance information gathering; not intended for
* public use. Serializes the message in AMF format and returns the size of
* the serialized message.
*
* @param message Message to get the size for.
*
* @return The size of the message after message is serialized.
*/
@Override protected long getMessageSizeForPerformanceInfo(Message message)
{
Amf3Output amfOut = new Amf3Output(serializationContext);
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
DataOutputStream dataOutStream = new DataOutputStream(outStream);
amfOut.setOutputStream(dataOutStream);
try
{
amfOut.writeObject(message);
}
catch (IOException e)
{
if (Log.isDebug())
log.debug("MPI exception while retrieving the size of the serialized message: " + e.toString());
}
return dataOutStream.size();
}
/**
* Returns the deserializer class name used by the endpoint.
*
* @return The deserializer class name used by the endpoint.
*/
@Override protected String getDeserializerClassName()
{
return "flex.messaging.io.amf.AmfMessageDeserializer";
}
/**
* Returns the serializer class name used by the endpoint.
*
* @return The serializer class name used by the endpoint.
*/
@Override protected String getSerializerClassName()
{
return "flex.messaging.io.amf.AmfMessageSerializer";
}
/**
* Invoked automatically to allow the StreamingAMFEndpoint to setup its
* corresponding MBean control.
*
* @param broker The MessageBroker that manages this
* StreamingAMFEndpoint.
*/
@Override protected void setupEndpointControl(MessageBroker broker)
{
controller = new StreamingAMFEndpointControl(this, broker.getControl());
controller.register();
setControl(controller);
}
/**
* Helper method invoked by the endpoint request handler thread cycling in wait-notify.
* Serializes messages and streams each to the client as a response chunk using streamChunk().
*
* @param messages The messages to serialize and push to the client.
* @param os The output stream the chunk will be written to.
* @param response The HttpServletResponse, used to flush the chunk to the client.
*/
@Override protected void streamMessages(List messages, ServletOutputStream os, HttpServletResponse response) throws IOException
{
if (messages == null || messages.isEmpty())
return;
// Serialize each message as a separate chunk of bytes.
TypeMarshallingContext.setTypeMarshaller(getTypeMarshaller());
for (Iterator iter = messages.iterator(); iter.hasNext();)
{
Message message = (Message)iter.next();
addPerformanceInfo(message);
message = convertPushMessageToSmall(message);
if (Log.isDebug())
log.debug("Endpoint with id '" + getId() + "' is streaming message: " + message);
Amf3Output amfOut = new Amf3Output(serializationContext);
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
DataOutputStream dataOutStream = new DataOutputStream(outStream);
amfOut.setOutputStream(dataOutStream);
amfOut.writeObject(message);
dataOutStream.flush();
byte[] messageBytes = outStream.toByteArray();
streamChunk(messageBytes, os, response);
if (isManaged())
((StreamingAMFEndpointControl)controller).incrementPushCount();
}
TypeMarshallingContext.setTypeMarshaller(null);
}
}