| file |
description |
|
Configures the BamService. |
|
The Java message listener. |
|
The PHP message listener. |
|
The custom message model. |
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The JSP demo |
|
The PHP demo |
Messaging lets a servlet delegate processing to a batch process either
on the same machine or on a separate machine. The servlet creates a message
and sends it to a queue. The servlet immediately completes and when the
batch process is ready, it processes the message.
Messaging is therefore comprised of three main components:
- A Producer creates messages and sends them to
a Consumer, continuing processing. The Producer could
be a Servlet or PHP page that sends a request to a backend consumer
and continues the web response without waiting for the task to complete.
- A Consumer processes messages as they become
available. In BAM, the Consumer extends
SimpleBamService to receive the messages.
- The Queue buffers messages from the Produces and provides
them to a Consumer when the Consumer is ready. The Queue is part of the BAM
messaging system.
In this example, the Producer is a Servlet which sends a simple message.
The Producer creates a LocalActorClient
to send the message.
import com.caucho.bam.LocalActorClient;
public void send()
{
LocalActorClient client = new LocalActorClient();
ExampleMessage message = new ExampleMessage("sample message");
client.message("consumer@", message);
client.close();
}
<?php
$msg = java("example.ExampleMessage", "sample message");
bam_send_message("consumer@", $msg);
?>
The Queue delivers message to the Consumer one by one. When the
Consumer finishes processing a message the Queue will deliver the next
available message. The Consumer
implements com.caucho.bam.BamService.
In this example, the Consumer just logs the message.
package example;
import com.caucho.bam.SimpleActor;
import com.caucho.bam.Message;
public class ExampleService extends SimpleActor;
{
@Message
public void onMessage(String to, String from, ExampleMessage message)
{
System.out.println("Message: " + message + " from=" + from);
}
}
The PHP version of the service implements a bam_message
method to handle the message and calls bam_dispatch() to
dispatch the message. The PHP service will call the bam_queue.php when
it receives a message.
<?php
function bam_message($to, $from, $value)
{
resin_debug($value);
}
bam_dispatch();
?>
<web-app xmlns="http://caucho.com/ns/resin">
<example:ExampleService>
<resin:BamService name="java-consumer"/>
</example:ExampleService>
<bam-service name="php-consumer"
uri="caucho.php:">
<init script="WEB-INF/php/bam_queue.php"/>
</bam-service>
</web-app>