25.2. Using Last-Value Property

The property name used to identify the last value is "_HQ_LVQ_NAME" (or the constant Message.HDR_LAST_VALUE_NAME from the Core API).
For example, if two messages with the same value for the Last-Value property are sent to a Last-Value queue, only the latest message will be kept in the queue: 
// send 1st message with Last-Value property set to STOCK_NAME
TextMessage message = 
  session.createTextMessage("1st message with Last-Value property set");
message.setStringProperty("_HQ_LVQ_NAME", "STOCK_NAME");
producer.send(message);

// send 2nd message with Last-Value property set to STOCK_NAME             
message = 
  session.createTextMessage("2nd message with Last-Value property set");
message.setStringProperty("_HQ_LVQ_NAME", "STOCK_NAME");
producer.send(message);
       
...
       
// only the 2nd message will be received: it is the latest with 
// the Last-Value property set
TextMessage messageReceived = (TextMessage)messageConsumer.receive(5000);
System.out.format("Received message: %s\n", messageReceived.getText());