Fix SmartLifecycle.stop(Runnable) usage (#2973)

* Fix `SmartLifecycle.stop(Runnable)` usage

We always have to call `callback` in the `SmartLifecycle.stop(Runnable)`
implementation independently of component state
* Fix `StandardIntegrationFlow.stop(Runnable)` for a logic when we
don't have any `this.lifecycles`
* Remove those `stop(Runnable)` which are fully equivalent of the
`default` on in the `SmartLifecycle`
* Some other simple polishing for the affected classes, e.g.
`isSingleton()` is `default` with `true` in the `InitializingBean`

**Cherry-pick to 5.1.x**

* * Fix checkstyle violation

spring-integration-core/src/main/java/org/springframework/integration/config/ConsumerEndpointFactoryBean.java

@@ -246,11 +246,6 @@ public class ConsumerEndpointFactoryBean
 		}
 	}
 
-	@Override
-	public boolean isSingleton() {
-		return true;
-	}
-
 	@Override
 	public AbstractEndpoint getObject() {
 		if (!this.initialized) {
@@ -302,8 +297,9 @@ public class ConsumerEndpointFactoryBean
 	}
 
 	private void eventDrivenConsumer(MessageChannel channel) {
-		Assert.isNull(this.pollerMetadata, "A poller should not be specified for endpoint '" + this.beanName
-				+ "', since '" + channel + "' is a SubscribableChannel (not pollable).");
+		Assert.isNull(this.pollerMetadata,
+				() -> "A poller should not be specified for endpoint '" + this.beanName
+						+ "', since '" + channel + "' is a SubscribableChannel (not pollable).");
 		this.endpoint = new EventDrivenConsumer((SubscribableChannel) channel, this.handler);
 		if (logger.isWarnEnabled()
 				&& Boolean.FALSE.equals(this.autoStartup)
@@ -316,8 +312,9 @@ public class ConsumerEndpointFactoryBean
 		PollingConsumer pollingConsumer = new PollingConsumer((PollableChannel) channel, this.handler);
 		if (this.pollerMetadata == null) {
 			this.pollerMetadata = PollerMetadata.getDefaultPollerMetadata(this.beanFactory);
-			Assert.notNull(this.pollerMetadata, "No poller has been defined for endpoint '" + this.beanName
-					+ "', and no default poller is available within the context.");
+			Assert.notNull(this.pollerMetadata,
+					() -> "No poller has been defined for endpoint '" + this.beanName
+							+ "', and no default poller is available within the context.");
 		}
 		pollingConsumer.setTaskExecutor(this.pollerMetadata.getTaskExecutor());
 		pollingConsumer.setTrigger(this.pollerMetadata.getTrigger());

spring-integration-core/src/main/java/org/springframework/integration/config/SourcePollingChannelAdapterFactoryBean.java

@@ -157,11 +157,6 @@ public class SourcePollingChannelAdapterFactoryBean implements FactoryBean<Sourc
 		return SourcePollingChannelAdapter.class;
 	}
 
-	@Override
-	public boolean isSingleton() {
-		return true;
-	}
-
 	private void initializeAdapter() {
 		synchronized (this.initializationMonitor) {
 			if (this.initialized) {

spring-integration-core/src/main/java/org/springframework/integration/dsl/StandardIntegrationFlow.java

@@ -127,17 +127,22 @@ public class StandardIntegrationFlow implements IntegrationFlow, SmartLifecycle
 
 	@Override
 	public void stop(Runnable callback) {
-		AggregatingCallback aggregatingCallback = new AggregatingCallback(this.lifecycles.size(), callback);
-		ListIterator<SmartLifecycle> iterator = this.lifecycles.listIterator(this.lifecycles.size());
-		while (iterator.hasPrevious()) {
-			SmartLifecycle lifecycle = iterator.previous();
-			if (lifecycle.isRunning()) {
-				lifecycle.stop(aggregatingCallback);
-			}
-			else {
-				aggregatingCallback.run();
+		if (this.lifecycles.size() > 0) {
+			AggregatingCallback aggregatingCallback = new AggregatingCallback(this.lifecycles.size(), callback);
+			ListIterator<SmartLifecycle> iterator = this.lifecycles.listIterator(this.lifecycles.size());
+			while (iterator.hasPrevious()) {
+				SmartLifecycle lifecycle = iterator.previous();
+				if (lifecycle.isRunning()) {
+					lifecycle.stop(aggregatingCallback);
+				}
+				else {
+					aggregatingCallback.run();
+				}
 			}
 		}
+		else {
+			callback.run();
+		}
 		this.running = false;
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/history/MessageHistoryConfigurer.java

@@ -52,7 +52,7 @@ import org.springframework.util.StringUtils;
 @IntegrationManagedResource
 public class MessageHistoryConfigurer implements SmartLifecycle, BeanFactoryAware, DestructionAwareBeanPostProcessor {
 
-	private final Log logger = LogFactory.getLog(this.getClass());
+	private static final Log logger = LogFactory.getLog(MessageHistoryConfigurer.class);
 
 	private final Set<TrackableComponent> currentlyTrackedComponents = ConcurrentHashMap.newKeySet();
 
@@ -230,12 +230,6 @@ public class MessageHistoryConfigurer implements SmartLifecycle, BeanFactoryAwar
 		}
 	}
 
-	@Override
-	public void stop(Runnable callback) {
-		this.stop();
-		callback.run();
-	}
-
 	private static Collection<TrackableComponent> getTrackableComponents(ListableBeanFactory beanFactory) {
 		return BeanFactoryUtils.beansOfTypeIncludingAncestors(beanFactory, TrackableComponent.class).values();
 	}

spring-integration-core/src/main/java/org/springframework/integration/store/MessageGroupStoreReaper.java

@@ -39,20 +39,20 @@ public class MessageGroupStoreReaper implements Runnable, DisposableBean, Initia
 
 	private static Log logger = LogFactory.getLog(MessageGroupStoreReaper.class);
 
+	private final ReentrantLock lifecycleLock = new ReentrantLock();
+
 	private MessageGroupStore messageGroupStore;
 
 	private boolean expireOnDestroy = false;
 
 	private long timeout = -1;
 
+	private int phase = 0;
+
+	private boolean autoStartup = true;
+
 	private volatile boolean running;
 
-	private final ReentrantLock lifecycleLock = new ReentrantLock();
-
-	private volatile int phase = 0;
-
-	private volatile boolean autoStartup = true;
-
 	public MessageGroupStoreReaper(MessageGroupStore messageGroupStore) {
 		this.messageGroupStore = messageGroupStore;
 	}
@@ -63,7 +63,6 @@ public class MessageGroupStoreReaper implements Runnable, DisposableBean, Initia
 	/**
 	 * Flag to indicate that the stores should be expired when this component is destroyed (i.e. usually when its
 	 * enclosing {@link org.springframework.context.ApplicationContext} is closed).
-	 *
 	 * @param expireOnDestroy the flag value to set
 	 */
 	public void setExpireOnDestroy(boolean expireOnDestroy) {
@@ -73,7 +72,6 @@ public class MessageGroupStoreReaper implements Runnable, DisposableBean, Initia
 	/**
 	 * Timeout in milliseconds (default -1). If negative then no groups ever time out. If greater than zero then all
 	 * groups older than that value are expired when this component is {@link #run()}.
-	 *
 	 * @param timeout the timeout to set
 	 */
 	public void setTimeout(long timeout) {
@@ -82,7 +80,6 @@ public class MessageGroupStoreReaper implements Runnable, DisposableBean, Initia
 
 	/**
 	 * A message group store to expire according the other configurations.
-	 *
 	 * @param messageGroupStore the {@link MessageGroupStore} to set
 	 */
 	public void setMessageGroupStore(MessageGroupStore messageGroupStore) {
@@ -187,16 +184,4 @@ public class MessageGroupStoreReaper implements Runnable, DisposableBean, Initia
 		this.autoStartup = autoStartup;
 	}
 
-	@Override
-	public void stop(Runnable callback) {
-		this.lifecycleLock.lock();
-		try {
-			this.stop();
-			callback.run();
-		}
-		finally {
-			this.lifecycleLock.unlock();
-		}
-	}
-
 }

spring-integration-core/src/main/java/org/springframework/integration/support/leader/LockRegistryLeaderInitiator.java

@@ -308,12 +308,6 @@ public class LockRegistryLeaderInitiator implements SmartLifecycle, DisposableBe
 		}
 	}
 
-	@Override
-	public void stop(Runnable runnable) {
-		stop();
-		runnable.run();
-	}
-
 	/**
 	 * Stop the registration of the {@link #candidate} for leader election. If the
 	 * candidate is currently leader, its leadership will be revoked.