Added the MessagePriority enum (INT-141).

spring-integration-core/src/main/java/org/springframework/integration/channel/PriorityChannel.java

@@ -23,6 +23,7 @@ import java.util.concurrent.TimeUnit;
 
 import org.springframework.integration.message.Message;
 import org.springframework.integration.message.MessageHeader;
+import org.springframework.integration.message.MessagePriority;
 
 /**
  * A message channel that prioritizes messages based on a {@link Comparator}.
@@ -97,8 +98,8 @@ public class PriorityChannel extends BaseBlockingQueueChannel {
 	private static class MessagePriorityComparator implements Comparator<Message<?>> {
 
 		public int compare(Message<?> message1, Message<?> message2) {
-			Integer priority1 = message1.getHeader().getPriority();
-			Integer priority2 = message2.getHeader().getPriority();
+			MessagePriority priority1 = message1.getHeader().getPriority();
+			MessagePriority priority2 = message2.getHeader().getPriority();
 			return priority1.compareTo(priority2);
 		}
 	}

spring-integration-core/src/main/java/org/springframework/integration/message/MessageHeader.java

@@ -46,7 +46,7 @@ public class MessageHeader {
 
 	private volatile int sequenceSize = 1;
 
-	private volatile int priority = 0;
+	private volatile MessagePriority priority = MessagePriority.NORMAL;
 
 	private final Properties properties = new Properties();
 
@@ -108,11 +108,11 @@ public class MessageHeader {
 		this.sequenceSize = sequenceSize;
 	}
 
-	public int getPriority() {
+	public MessagePriority getPriority() {
 		return this.priority;
 	}
 
-	public void setPriority(int priority) {
+	public void setPriority(MessagePriority priority) {
 		this.priority = priority;
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/message/MessagePriority.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2002-2007 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.message;
+
+/**
+ * An enumeration of the possible values for a message's priority. 
+ * 
+ * @author Mark Fisher
+ * @see MessageHeader#getPriority()
+ * @see MessageHeader#setPriority(MessagePriority)
+ */
+public enum MessagePriority {
+
+	HIGHEST,
+	HIGH,
+	NORMAL,
+	LOW,
+	LOWEST
+
+}

spring-integration-core/src/test/java/org/springframework/integration/channel/PriorityChannelTests.java

@@ -25,6 +25,7 @@ import java.util.Comparator;
 import org.junit.Test;
 
 import org.springframework.integration.message.Message;
+import org.springframework.integration.message.MessagePriority;
 import org.springframework.integration.message.StringMessage;
 
 /**
@@ -46,21 +47,21 @@ public class PriorityChannelTests {
 	@Test
 	public void testDefaultComparator() {
 		PriorityChannel channel = new PriorityChannel(5);
-		Message<?> priority1 = createPriorityMessage(1);
-		Message<?> priority2 = createPriorityMessage(2);
-		Message<?> priority3 = createPriorityMessage(3);
-		Message<?> priority4 = createPriorityMessage(4);
-		Message<?> priority5 = createPriorityMessage(5);
+		Message<?> priority1 = createPriorityMessage(MessagePriority.HIGHEST);
+		Message<?> priority2 = createPriorityMessage(MessagePriority.HIGH);
+		Message<?> priority3 = createPriorityMessage(MessagePriority.NORMAL);
+		Message<?> priority4 = createPriorityMessage(MessagePriority.LOW);
+		Message<?> priority5 = createPriorityMessage(MessagePriority.LOWEST);
 		channel.send(priority4);
 		channel.send(priority3);
 		channel.send(priority5);
 		channel.send(priority1);
 		channel.send(priority2);
-		assertEquals("test-1", channel.receive(0).getPayload());
-		assertEquals("test-2", channel.receive(0).getPayload());
-		assertEquals("test-3", channel.receive(0).getPayload());
-		assertEquals("test-4", channel.receive(0).getPayload());
-		assertEquals("test-5", channel.receive(0).getPayload());
+		assertEquals("test-HIGHEST", channel.receive(0).getPayload());
+		assertEquals("test-HIGH", channel.receive(0).getPayload());
+		assertEquals("test-NORMAL", channel.receive(0).getPayload());
+		assertEquals("test-LOW", channel.receive(0).getPayload());
+		assertEquals("test-LOWEST", channel.receive(0).getPayload());
 	}
 
 	@Test
@@ -84,7 +85,7 @@ public class PriorityChannelTests {
 	}
 
 
-	private static Message<?> createPriorityMessage(int priority) {
+	private static Message<?> createPriorityMessage(MessagePriority priority) {
 		Message<?> message = new StringMessage("test-" + priority);
 		message.getHeader().setPriority(priority);
 		return message;

spring-integration-core/src/test/java/org/springframework/integration/config/ChannelParserTests.java

@@ -36,6 +36,7 @@ import org.springframework.integration.handler.MessageHandler;
 import org.springframework.integration.message.GenericMessage;
 import org.springframework.integration.message.Message;
 import org.springframework.integration.message.MessageDeliveryException;
+import org.springframework.integration.message.MessagePriority;
 import org.springframework.integration.message.StringMessage;
 import org.springframework.integration.scheduling.SimpleMessagingTaskScheduler;
 
@@ -211,11 +212,11 @@ public class ChannelParserTests {
 				"priorityChannelParserTests.xml", this.getClass());
 		MessageChannel channel = (MessageChannel) context.getBean("priorityChannelWithDefaultComparator");
 		Message<?> lowPriorityMessage = new StringMessage("low");
-		lowPriorityMessage.getHeader().setPriority(777);
+		lowPriorityMessage.getHeader().setPriority(MessagePriority.LOW);
 		Message<?> midPriorityMessage = new StringMessage("mid");
-		midPriorityMessage.getHeader().setPriority(77);
+		midPriorityMessage.getHeader().setPriority(MessagePriority.NORMAL);
 		Message<?> highPriorityMessage = new StringMessage("high");
-		highPriorityMessage.getHeader().setPriority(7);
+		highPriorityMessage.getHeader().setPriority(MessagePriority.HIGH);
 		channel.send(lowPriorityMessage);
 		channel.send(highPriorityMessage);
 		channel.send(midPriorityMessage);