From a7891c3dca7b598b4664574bc88e0802e16df6ef Mon Sep 17 00:00:00 2001
From: "Hiram R. Chirino" <chirino@apache.org>
Date: Sun, 3 Sep 2006 17:09:51 +0000
Subject: [PATCH] Patch applied from Vadim:
 https://issues.apache.org/activemq/browse/AMQ-855

git-svn-id: https://svn.apache.org/repos/asf/incubator/activemq/trunk@439804 13f79535-47bb-0310-9956-ffa450edef68
---
 ...ference.java => NullMessageReference.java} |  9 +++--
 .../broker/region/QueueMessageReference.java  |  2 +-
 .../activemq/ZeroPrefetchConsumerTest.java    | 36 ++++++++++++++-----
 3 files changed, 32 insertions(+), 15 deletions(-)
 rename activemq-core/src/main/java/org/apache/activemq/broker/region/{EndOfBrowseMarkerQueueMessageReference.java => NullMessageReference.java} (91%)

diff --git a/activemq-core/src/main/java/org/apache/activemq/broker/region/EndOfBrowseMarkerQueueMessageReference.java b/activemq-core/src/main/java/org/apache/activemq/broker/region/NullMessageReference.java
similarity index 91%
rename from activemq-core/src/main/java/org/apache/activemq/broker/region/EndOfBrowseMarkerQueueMessageReference.java
rename to activemq-core/src/main/java/org/apache/activemq/broker/region/NullMessageReference.java
index 9a5d2730b6..86bfce4e69 100644
--- a/activemq-core/src/main/java/org/apache/activemq/broker/region/EndOfBrowseMarkerQueueMessageReference.java
+++ b/activemq-core/src/main/java/org/apache/activemq/broker/region/NullMessageReference.java
@@ -27,7 +27,7 @@ import org.apache.activemq.command.MessageId;
 /**
  * Only used by the {@link QueueMessageReference#NULL_MESSAGE} 
  */
-final class EndOfBrowseMarkerQueueMessageReference implements
+final class NullMessageReference implements
 		QueueMessageReference {
 
 	private ActiveMQMessage message = new ActiveMQMessage();
@@ -50,7 +50,7 @@ final class EndOfBrowseMarkerQueueMessageReference implements
 	}
 
 	public boolean lock(LockOwner subscription) {
-		throw new RuntimeException("not implemented");
+		return true;
 	}
 
 	public void setAcked(boolean b) {
@@ -58,7 +58,6 @@ final class EndOfBrowseMarkerQueueMessageReference implements
 	}
 
 	public void unlock() {
-		throw new RuntimeException("not implemented");
 	}
 
 	public int decrementReferenceCount() {
@@ -70,11 +69,11 @@ final class EndOfBrowseMarkerQueueMessageReference implements
 	}
 
 	public String getGroupID() {
-		throw new RuntimeException("not implemented");
+		return null;
 	}
 
 	public int getGroupSequence() {
-		throw new RuntimeException("not implemented");
+		return 0;
 	}
 
 	public Message getMessage() throws IOException {
diff --git a/activemq-core/src/main/java/org/apache/activemq/broker/region/QueueMessageReference.java b/activemq-core/src/main/java/org/apache/activemq/broker/region/QueueMessageReference.java
index dad84fb918..3fa7ee5d83 100644
--- a/activemq-core/src/main/java/org/apache/activemq/broker/region/QueueMessageReference.java
+++ b/activemq-core/src/main/java/org/apache/activemq/broker/region/QueueMessageReference.java
@@ -25,7 +25,7 @@ package org.apache.activemq.broker.region;
  */
 public interface QueueMessageReference extends MessageReference {
 
-    public static final QueueMessageReference NULL_MESSAGE = new EndOfBrowseMarkerQueueMessageReference();
+    public static final QueueMessageReference NULL_MESSAGE = new NullMessageReference();
 
     public boolean isAcked();
     
diff --git a/activemq-core/src/test/java/org/apache/activemq/ZeroPrefetchConsumerTest.java b/activemq-core/src/test/java/org/apache/activemq/ZeroPrefetchConsumerTest.java
index 2208ebfefe..8f15ad40fb 100644
--- a/activemq-core/src/test/java/org/apache/activemq/ZeroPrefetchConsumerTest.java
+++ b/activemq-core/src/test/java/org/apache/activemq/ZeroPrefetchConsumerTest.java
@@ -21,14 +21,7 @@ import org.apache.activemq.spring.SpringConsumer;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import javax.jms.Connection;
-import javax.jms.JMSException;
-import javax.jms.Message;
-import javax.jms.MessageConsumer;
-import javax.jms.MessageListener;
-import javax.jms.MessageProducer;
-import javax.jms.Queue;
-import javax.jms.Session;
+import javax.jms.*;
 
 /**
  * 
@@ -60,11 +53,36 @@ public class ZeroPrefetchConsumerTest extends EmbeddedBrokerTestSupport {
 
         MessageProducer producer = session.createProducer(queue);
         producer.send(session.createTextMessage("Hello World!"));
-        
+
         // now lets receive it
         MessageConsumer consumer = session.createConsumer(queue);
         Message answer = consumer.receive(5000);
         assertNotNull("Should have received a message!", answer);
+        // check if method will return at all and will return a null
+        answer = consumer.receive(1000);
+        assertNull("Should have not received a message!", answer);
+        answer = consumer.receiveNoWait();
+        assertNull("Should have not received a message!", answer);
+    }
+
+    public void testIdleConsumer() throws Exception {
+        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
+
+        MessageProducer producer = session.createProducer(queue);
+        producer.send(session.createTextMessage("Msg1"));
+        producer.send(session.createTextMessage("Msg2"));
+
+        // now lets receive it
+        MessageConsumer consumer = session.createConsumer(queue);
+        //noinspection UNUSED_SYMBOL
+        MessageConsumer idleConsumer = session.createConsumer(queue);
+        TextMessage answer = (TextMessage) consumer.receive(5000);
+        assertEquals("Should have received a message!", answer.getText(), "Msg1");
+        // this call would return null if prefetchSize > 0
+        answer = (TextMessage) consumer.receive(5000);
+        assertEquals("Should have not received a message!", answer.getText(), "Msg2");
+        answer = (TextMessage) consumer.receiveNoWait();
+        assertNull("Should have not received a message!", answer);
     }
 
     protected void setUp() throws Exception {