The Messaging Service lets client applications send and receive messages from other clients. In this example, create a Flex application that sends and receives messages from the same BlazeDS destination.
Define the messaging destination in WEB-INF/flex/messaging-config.xml, as the following example shows:
<destination id="MessagingDestination" channels="my-amf-poll"/>
Define the my-amf-poll channel in WEB-INF/flex/services-config.xml, as the following example shows:
<channel-definition id="my-amf-poll" class="mx.messaging.channels.AMFChannel">
<endpoint url="http://{server.name}:{server.port}/{context.root}/messagebroker/amfpoll" class="flex.messaging.endpoints.AMFEndpoint"/>
<properties>
<polling-enabled>true</polling-enabled>
<polling-interval-seconds>1</polling-interval-seconds>
</properties>
</channel-definition>
This channel definition creates a polling channel with a polling interval of 1 second. Therefore, the client sends a poll message to the server every second to request new messages. Use a polling channel because it is the easiest way for the client to receive updates. Other options include polling with piggybacking, long-polling, and streaming.The following
Flex client application uses the Producer component to send a message to the destination, and the
Consumer component to receive messages sent to the destination. To send the message, the Producer first creates an instance of the AsyncMessage class and then sets its body property to the message. Then, it calls the Producer.send() method to send it. To receive messages, the Consumer first calls the Consumer.subscribe() method to subscribe to messages sent to a specific destination.
<?xml version="1.0"?>
<!-- intro\intro_messaging.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
width="100%" height="100%"
creationComplete="consumer.subscribe();">
<mx:Script>
<![CDATA[
import mx.messaging.events.MessageFaultEvent;
import mx.messaging.events.MessageEvent;
import mx.messaging.messages.AsyncMessage;
import mx.messaging.Producer;
import mx.messaging.Consumer;
// Send the message in response to a Button click.
private function sendMessage():void {
var msg:AsyncMessage = new AsyncMessage();
msg.body = "Foo";
producer.send(msg);
}
// Handle the received message.
private function messageHandler(event:MessageEvent):void {
ta.text += "Consumer received message: "+ event.message.body + "\n";
}
// Handle a message fault.
private function faultHandler(event:MessageFaultEvent):void {
ta.text += "Received fault: " + event.faultString + "\n";
}
]]>
</mx:Script>
<mx:Producer id="producer" destination="MessagingDestination" fault="faultHandler(event);"/>
<mx:Consumer id="consumer" destination="MessagingDestination" fault="faultHandler(event);" message="messageHandler(event);"/>
<mx:Button label="Send" click="sendMessage();"/>
<mx:TextArea id="ta" width="100%" height="100%"/>
</mx:Application>
Compile the client application into a SWF file by using Flex Builder or the mxmlc compiler, and then deploy it to
your web application.