IN PROGRESS - issue INT-567: Add round-robin dispatching strategy

http://jira.springframework.org/browse/INT-567

- Renamed LoadBalancingDispatcher to more explicit RoundRobinDispatcher
- Removed round-robin option from xsd (not specifying a dispatcher yields the same)

org.springframework.integration/src/main/java/org/springframework/integration/channel/DirectChannel.java

@@ -17,7 +17,7 @@
 package org.springframework.integration.channel;
 
 import org.springframework.integration.dispatcher.AbstractWinningHandlerDispatcher;
-import org.springframework.integration.dispatcher.LoadBalancingDispatcher;
+import org.springframework.integration.dispatcher.RoundRobinDispatcher;
 
 /**
  * A channel that invokes a single subscriber for each sent Message.
@@ -30,8 +30,9 @@ import org.springframework.integration.dispatcher.LoadBalancingDispatcher;
 public class DirectChannel extends AbstractSubscribableChannel<AbstractWinningHandlerDispatcher> {
 
 	public DirectChannel() {
-		super(new LoadBalancingDispatcher());
+		super(new RoundRobinDispatcher());
 	}
+	
 	public DirectChannel(AbstractWinningHandlerDispatcher dispatcher){
 		super(dispatcher);
 	}

org.springframework.integration/src/main/java/org/springframework/integration/config/xml/PointToPointChannelParser.java

@@ -65,7 +65,7 @@ public class PointToPointChannelParser extends AbstractChannelParser {
 
 	private void parseDispatcher(String dispatcherAttribute, BeanDefinitionBuilder builder, ParserContext parserContext) {
 		if (dispatcherAttribute != null) {
-			if (dispatcherAttribute.equals("fail-over")) {
+			if (dispatcherAttribute.equals("failover")) {
 				BeanDefinitionBuilder dispatcherBuilder = BeanDefinitionBuilder
 						.genericBeanDefinition(DISPATCHER_PACKAGE + ".FailOverDispatcher");
 				dispatcherBuilder.setRole(BeanDefinition.ROLE_SUPPORT);

org.springframework.integration/src/main/java/org/springframework/integration/config/xml/spring-integration-1.0.xsd

@@ -166,9 +166,19 @@
 		<xsd:attribute name="datatype" type="xsd:string" />
 		<xsd:attribute name="dispatcher">
 			<xsd:simpleType>
+				<xsd:annotation>
+					<xsd:documentation>
+						Defines a dispatching strategy for the channel. The default is a round
+						robin load balancer. In case of a publish subscribe channel this
+						attribute will be ignored.
+					</xsd:documentation>
+				</xsd:annotation>
 				<xsd:restriction base="xsd:string">
-					<xsd:enumeration value="fail-over" />
-					<xsd:enumeration value="round-robin" />
+					<xsd:enumeration value="failover" />
+					<!--
+						now the other (default) option is round robin load balancing we
+						can add more options later
+					-->
 				</xsd:restriction>
 			</xsd:simpleType>
 		</xsd:attribute>

org.springframework.integration/src/main/java/org/springframework/integration/dispatcher/RoundRobinDispatcher.java

@@ -24,7 +24,7 @@ import java.util.concurrent.atomic.AtomicInteger;
  * 
  * @author Iwein Fuld
  */
-public class LoadBalancingDispatcher extends AbstractWinningHandlerDispatcher {
+public class RoundRobinDispatcher extends AbstractWinningHandlerDispatcher {
 
 	private AtomicInteger currentHandlerIndex = new AtomicInteger();
 

org.springframework.integration/src/test/java/org/springframework/integration/channel/config/ChannelParserTests.java

@@ -38,7 +38,7 @@ import org.springframework.integration.core.Message;
 import org.springframework.integration.core.MessageChannel;
 import org.springframework.integration.core.MessagePriority;
 import org.springframework.integration.dispatcher.FailOverDispatcher;
-import org.springframework.integration.dispatcher.LoadBalancingDispatcher;
+import org.springframework.integration.dispatcher.RoundRobinDispatcher;
 import org.springframework.integration.message.GenericMessage;
 import org.springframework.integration.message.MessageBuilder;
 import org.springframework.integration.message.MessageDeliveryException;
@@ -75,7 +75,7 @@ public class ChannelParserTests {
 		MessageChannel channel = (MessageChannel) context.getBean("defaultChannel");
 		assertEquals(DirectChannel.class, channel.getClass());
 		DirectFieldAccessor accessor = new DirectFieldAccessor(channel);
-		assertThat(accessor.getPropertyValue("dispatcher"), is(LoadBalancingDispatcher.class));
+		assertThat(accessor.getPropertyValue("dispatcher"), is(RoundRobinDispatcher.class));
 	}
 
 	@Test

org.springframework.integration/src/test/java/org/springframework/integration/channel/config/channelParserTests.xml

@@ -12,7 +12,7 @@
 
 	<channel id="defaultChannel" />
 	
-	<channel id="failOverChannel" dispatcher="fail-over"/>
+	<channel id="failOverChannel" dispatcher="failover"/>
 
 	<publish-subscribe-channel id="publishSubscribeChannel" />
 

org.springframework.integration/src/test/java/org/springframework/integration/dispatcher/RoundRobinDispatcherConcurrentTests.java

@@ -16,11 +16,11 @@ import org.springframework.integration.message.MessageHandler;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
 @RunWith(MockitoJUnit44Runner.class)
-public class LoadBalancingDispatcherConcurrentTests {
+public class RoundRobinDispatcherConcurrentTests {
 
 	private static final int TOTAL_EXECUTIONS = 40;
 
-	private AbstractWinningHandlerDispatcher dispatcher = new LoadBalancingDispatcher();
+	private AbstractWinningHandlerDispatcher dispatcher = new RoundRobinDispatcher();
 
 	private ThreadPoolTaskExecutor scheduler = new ThreadPoolTaskExecutor();
 

org.springframework.integration/src/test/java/org/springframework/integration/dispatcher/RoundRobinDispatcherTests.java

@@ -33,9 +33,9 @@ import org.springframework.integration.message.MessageHandler;
  * 
  */
 @RunWith(MockitoJUnit44Runner.class)
-public class LoadBalancingDispatcherTests {
+public class RoundRobinDispatcherTests {
 
-	private AbstractWinningHandlerDispatcher dispatcher = new LoadBalancingDispatcher();
+	private AbstractWinningHandlerDispatcher dispatcher = new RoundRobinDispatcher();
 
 	@Mock
 	private MessageHandler handler;