Allow consumer to stop processing messages upon closing

Author: zeroorone-huff

src/main/java/com/amazon/sqs/javamessaging/SQSMessageConsumerPrefetch.java

@@ -570,9 +570,14 @@ private javax.jms.Message messageHandler(MessageManager messageManager) throws J
     }
 
     private boolean cannotDeliver() throws JMSException {
-        if (isClosed() || !running) {
-            return true;
+        if (!running) {
+          return true;
         }
+
+        if (isClosed()) {
+          throw new JMSException("Cannot receive messages when the consumer is closed");
+        }
+
         if (messageListener != null) {
             throw new JMSException("Cannot receive messages synchronously after a message listener is set");
         }