INT-2352 Support Control-Bus Atomic Router Updates

JIRA: https://jira.spring.io/browse/INT-2352

Add `replaceChannelMappings()` to the `AMMR`.

INT-2352 Polishing - PR Comments

Consolidate tests.
Fix up `@ManagedAttribute` Vs `@ManagedOperation`
Expose `setChannelMappings` over JMX

spring-integration-core/src/main/java/org/springframework/integration/router/AbstractMappingMessageRouter.java

@@ -22,10 +22,13 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.integration.support.channel.BeanFactoryChannelResolver;
+import org.springframework.jmx.export.annotation.ManagedAttribute;
 import org.springframework.jmx.export.annotation.ManagedOperation;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
@@ -64,15 +67,13 @@ public abstract class AbstractMappingMessageRouter extends AbstractMessageRouter
 	 *
 	 * @param channelMappings The channel mappings.
 	 */
+	@Override
+	@ManagedAttribute
 	public void setChannelMappings(Map<String, String> channelMappings) {
-		Map<String, String> oldChannelMappings = this.channelMappings;
+		Assert.notNull(channelMappings, "'channelMappings' must not be null");
 		Map<String, String> newChannelMappings = new ConcurrentHashMap<String, String>();
 		newChannelMappings.putAll(channelMappings);
-		this.channelMappings = newChannelMappings;
-		if (logger.isDebugEnabled()) {
-			logger.debug("Channel mappings:" + oldChannelMappings
-					+ " replaced with:" + newChannelMappings);
-		}
+		this.doSetChannelMappings(newChannelMappings);
 	}
 
 	/**
@@ -122,7 +123,9 @@ public abstract class AbstractMappingMessageRouter extends AbstractMessageRouter
 	 *
 	 * @return The channel mappings.
 	 */
-	protected Map<String, String> getChannelMappings() {
+	@Override
+	@ManagedAttribute
+	public Map<String, String> getChannelMappings() {
 		return Collections.unmodifiableMap(this.channelMappings);
 	}
 
@@ -176,6 +179,38 @@ public abstract class AbstractMappingMessageRouter extends AbstractMessageRouter
 		return channels;
 	}
 
+	/**
+	 * Convenience method allowing conversion of a list
+	 * of mappings in a control-bus message.
+	 * <p>This is intended to be called via a control-bus; keys and values that are not
+	 * Strings will be ignored.
+	 * <p>Mappings must be delimited with newlines, for example:
+	 * <p>{@code "@'myRouter.handler'.replaceChannelMappings('foo=qux \n baz=bar')"}.
+	 * @param channelMappings The channel mappings.
+	 *
+	 * @since 4.0
+	 */
+	@Override
+	@ManagedOperation
+	public void replaceChannelMappings(Properties channelMappings) {
+		Assert.notNull(channelMappings, "'channelMappings' must not be null");
+		Map<String, String> newChannelMappings = new ConcurrentHashMap<String, String>();
+		Set<String> keys = channelMappings.stringPropertyNames();
+		for (String key : keys) {
+			newChannelMappings.put(key.trim(), channelMappings.getProperty(key).trim());
+		}
+		this.doSetChannelMappings(newChannelMappings);
+	}
+
+	private void doSetChannelMappings(Map<String, String> newChannelMappings) {
+		Map<String, String> oldChannelMappings = this.channelMappings;
+		this.channelMappings = newChannelMappings;
+		if (logger.isDebugEnabled()) {
+			logger.debug("Channel mappings:" + oldChannelMappings
+					+ " replaced with:" + newChannelMappings);
+		}
+	}
+
 	private MessageChannel resolveChannelForName(String channelName, Message<?> message) {
 		if (this.channelResolver == null) {
 			this.onInit();

spring-integration-core/src/main/java/org/springframework/integration/router/MappingMessageRouterManagement.java

@@ -15,9 +15,19 @@
  */
 package org.springframework.integration.router;
 
+import java.util.Map;
+import java.util.Properties;
+
+import org.springframework.jmx.export.annotation.ManagedAttribute;
 import org.springframework.jmx.export.annotation.ManagedOperation;
+import org.springframework.messaging.core.DestinationResolver;
 
 /**
+ * Exposes channel mapping operations when the router is proxied.
+ * {@link #setChannelMappings(Map)} is also exposed. This cannot
+ * be used with a control-bus, but it can be used programmatically
+ * or over JMX.
+ *
  * @author Gary Russell
  * @since 2.1
  *
@@ -26,19 +36,45 @@ public interface MappingMessageRouterManagement {
 
 	/**
 	 * Add a channel mapping from the provided key to channel name.
-	 *
 	 * @param key The key.
 	 * @param channelName The channel name.
 	 */
 	@ManagedOperation
-	public abstract void setChannelMapping(String key, String channelName);
+	void setChannelMapping(String key, String channelName);
 
 	/**
 	 * Remove a channel mapping for the given key if present.
-	 *
 	 * @param key The key.
 	 */
 	@ManagedOperation
-	public abstract void removeChannelMapping(String key);
+	void removeChannelMapping(String key);
+
+	/**
+	 * Provide mappings from channel keys to channel names.
+	 * @param channelMappings The channel mappings.
+	 *
+	 * @since 4.0
+	 */
+	@ManagedOperation
+	void replaceChannelMappings(Properties channelMappings);
+
+	/**
+	 * @return an unmodifiable map of channel mappings.
+	 *
+	 * @since 4.0
+	 */
+	@ManagedAttribute
+	Map<String, String> getChannelMappings();
+
+	/**
+	 * Provide mappings from channel keys to channel names.
+	 * Channel names will be resolved by the {@link DestinationResolver}.
+	 *
+	 * @param channelMappings The channel mappings.
+	 *
+	 * @since 4.0
+	 */
+	@ManagedAttribute
+	void setChannelMappings(Map<String, String> channelMappings);
 
 }

spring-integration-core/src/test/java/org/springframework/integration/config/xml/ControlBusTests-context.xml

@@ -14,4 +14,13 @@
 
 	<beans:bean id="service" class="org.springframework.integration.config.xml.ControlBusTests$Service" />
 
+	<router id="router" expression="headers['channel']" input-channel="routerIn">
+		<mapping value="foo" channel="bar" />
+		<mapping value="baz" channel="qux" />
+	</router>
+
+	<channel id="bar" />
+
+	<channel id="qux" />
+
 </beans:beans>

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

@@ -22,6 +22,7 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import java.util.Date;
+import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
@@ -40,6 +41,7 @@ import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.PollableChannel;
 import org.springframework.messaging.support.GenericMessage;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -51,6 +53,7 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
  */
 @ContextConfiguration
 @RunWith(SpringJUnit4ClassRunner.class)
+@DirtiesContext
 public class ControlBusTests {
 
 	@Autowired
@@ -115,6 +118,26 @@ public class ControlBusTests {
 		this.registry.setReaperDelay(60000);
 	}
 
+	@Test
+	public void testRouterMappings() {
+		MessagingTemplate messagingTemplate = new MessagingTemplate();
+		messagingTemplate.setReceiveTimeout(1000);
+		messagingTemplate.convertAndSend(input, "@'router.handler'.getChannelMappings()");
+		Message<?> result = this.output.receive(0);
+		assertNotNull(result);
+		Map<?, ?> mappings = (Map<?, ?>) result.getPayload();
+		assertEquals("bar", mappings.get("foo"));
+		assertEquals("qux", mappings.get("baz"));
+		messagingTemplate.convertAndSend(input,
+				"@'router.handler'.replaceChannelMappings('foo=qux \n baz=bar')");
+		messagingTemplate.convertAndSend(input, "@'router.handler'.getChannelMappings()");
+		result = this.output.receive(0);
+		assertNotNull(result);
+		mappings = (Map<?, ?>) result.getPayload();
+		assertEquals("bar", mappings.get("baz"));
+		assertEquals("qux", mappings.get("foo"));
+	}
+
 	public static class Service {
 
 		private final CountDownLatch latch = new CountDownLatch(1);