Subscribing to a JMS Topic

The following example demonstrates how to subscribe to a JMS Topic:

  function subscriptionCallback(message)
  {
    if (message instanceof Seam.Remoting.TextMessage)
      alert("Received message: " + message.getText());
  }        
        
  Seam.Remoting.subscribe("topicName", subscriptionCallback);

The Seam.Remoting.subscribe() method accepts two parameters, the first being the name of the JMS Topic to subscribe to, the second being the callback function to invoke when a message is received.

There are two types of messages supported, Text messages and Object messages. If you need to test for the type of message that is passed to your callback function you can use the instanceof operator to test whether the message is a Seam.Remoting.TextMessage or Seam.Remoting.ObjectMessage. A TextMessage contains the text value in its text field (or alternatively call getText() on it), while an ObjectMessage contains its object value in its object field (or call its getObject() method).