INT-4395: More micrometer meters

JIRA: https://jira.spring.io/browse/INT-4395

- pollable channel counts
- component counts (gauges)

Polishing - PR comments

Fix switch in test

* Simple code style polishing and fix JavaDocs

Author: garyrussell

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -103,7 +103,7 @@ public Message<?> receive(long timeout) {
 				}
 			}
 			Message<?> message = this.doReceive(timeout);
-			if (countsEnabled) {
+			if (countsEnabled && message != null) {
 				getMetrics().afterReceive();
 				counted = true;
 			}

spring-integration-core/src/main/java/org/springframework/integration/support/management/AbstractMessageChannelMetrics.java

@@ -29,6 +29,7 @@
  * Abstract base class for channel metrics implementations.
  *
  * @author Gary Russell
+ *
  * @since 4.2
  *
  */
@@ -42,32 +43,43 @@ public abstract class AbstractMessageChannelMetrics implements ConfigurableMetri
 
 	private final Counter errorCounter;
 
+	private final Counter receiveCounter;
+
+	private final Counter receiveErrorCounter;
+
 	private volatile boolean fullStatsEnabled;
 
 	/**
 	 * Construct an instance with the provided name.
 	 * @param name the name.
 	 */
 	public AbstractMessageChannelMetrics(String name) {
-		this(name, null, null);
+		this(name, null, null, null, null);
 	}
 
 	/**
-	 * Construct an instance with the provided name, timer and error counter.
+	 * Construct an instance with the provided name, timer, error counter, receive counter
+	 * and receive error counter.
 	 * A non-null timer requires a non-null error counter. When a timer is provided,
 	 * Micrometer metrics are used and the legacy metrics are not maintained.
 	 * @param name the name.
 	 * @param timer the timer.
 	 * @param errorCounter the error counter.
+	 * @param receiveCounter the receive counter.
+	 * @param receiveErrorCounter the receive error counter.
 	 * @since 5.0.2
 	 */
-	public AbstractMessageChannelMetrics(String name, Timer timer, Counter errorCounter) {
+	public AbstractMessageChannelMetrics(String name, Timer timer, Counter errorCounter, Counter receiveCounter,
+			Counter receiveErrorCounter) {
+
 		if (timer != null) {
 			Assert.notNull(errorCounter, "'errorCounter' cannot be null if a timer is provided");
 		}
 		this.name = name;
 		this.timer = timer;
 		this.errorCounter = errorCounter;
+		this.receiveCounter = receiveCounter;
+		this.receiveErrorCounter = receiveErrorCounter;
 	}
 
 	/**
@@ -124,6 +136,26 @@ public Counter getErrorCounter() {
 		return this.errorCounter;
 	}
 
+	/**
+	 * Return the receive counter if Micrometer metrics are being used.
+	 * @return the counter or null if Micrometer is not being used.
+	 * @since 5.0.2
+	 */
+	@Nullable
+	public Counter getReceiveCounter() {
+		return this.receiveCounter;
+	}
+
+	/**
+	 * Return the receive error counter if Micrometer metrics are being used.
+	 * @return the counter or null if Micrometer is not being used.
+	 * @since 5.0.2
+	 */
+	@Nullable
+	public Counter getReceiveErrorCounter() {
+		return this.receiveErrorCounter;
+	}
+
 	public abstract int getSendCount();
 
 	public abstract long getSendCountLong();

spring-integration-core/src/main/java/org/springframework/integration/support/management/DefaultMessageChannelMetrics.java

@@ -28,6 +28,7 @@
  * @author Helena Edelson
  * @author Gary Russell
  * @author Ivan Krizsan
+ *
  * @since 2.0
  */
 public class DefaultMessageChannelMetrics extends AbstractMessageChannelMetrics {
@@ -64,7 +65,7 @@ public DefaultMessageChannelMetrics() {
 	 * @param name the name.
 	 */
 	public DefaultMessageChannelMetrics(String name) {
-		this(name, null, null);
+		this(name, null, null, null, (Counter) null);
 	}
 
 	/**
@@ -73,17 +74,21 @@ public DefaultMessageChannelMetrics(String name) {
 	 * @param name the name.
 	 * @param timer a timer.
 	 * @param errorCounter a counter.
+	 * @param receiveCounter a counter for receives.
+	 * @param receiveErrorCounter a counter for receive errors.
 	 * @since 5.0.2
 	 */
-	public DefaultMessageChannelMetrics(String name, Timer timer, Counter errorCounter) {
+	public DefaultMessageChannelMetrics(String name, Timer timer, Counter errorCounter, Counter receiveCounter,
+			Counter receiveErrorCounter) {
+
 		this(name, new ExponentialMovingAverage(DEFAULT_MOVING_AVERAGE_WINDOW, 1000000.),
-			new ExponentialMovingAverageRate(
-					ONE_SECOND_SECONDS, ONE_MINUTE_SECONDS, DEFAULT_MOVING_AVERAGE_WINDOW, true),
-			new ExponentialMovingAverageRatio(
-					ONE_MINUTE_SECONDS, DEFAULT_MOVING_AVERAGE_WINDOW, true),
-			new ExponentialMovingAverageRate(
-					ONE_SECOND_SECONDS, ONE_MINUTE_SECONDS, DEFAULT_MOVING_AVERAGE_WINDOW, true),
-			timer, errorCounter);
+				new ExponentialMovingAverageRate(
+						ONE_SECOND_SECONDS, ONE_MINUTE_SECONDS, DEFAULT_MOVING_AVERAGE_WINDOW, true),
+				new ExponentialMovingAverageRatio(
+						ONE_MINUTE_SECONDS, DEFAULT_MOVING_AVERAGE_WINDOW, true),
+				new ExponentialMovingAverageRate(
+						ONE_SECOND_SECONDS, ONE_MINUTE_SECONDS, DEFAULT_MOVING_AVERAGE_WINDOW, true),
+				timer, errorCounter, receiveCounter, receiveErrorCounter);
 	}
 
 	/**
@@ -100,7 +105,8 @@ public DefaultMessageChannelMetrics(String name, Timer timer, Counter errorCount
 	public DefaultMessageChannelMetrics(String name, ExponentialMovingAverage sendDuration,
 			ExponentialMovingAverageRate sendErrorRate, ExponentialMovingAverageRatio sendSuccessRatio,
 			ExponentialMovingAverageRate sendRate) {
-		this(name, sendDuration, sendErrorRate, sendSuccessRatio, sendRate, null, null);
+
+		this(name, sendDuration, sendErrorRate, sendSuccessRatio, sendRate, null, null, null, null);
 	}
 
 	/**
@@ -113,13 +119,17 @@ public DefaultMessageChannelMetrics(String name, ExponentialMovingAverage sendDu
 	 * @param sendSuccessRatio an {@link ExponentialMovingAverageRatio} for calculating the success ratio.
 	 * @param sendRate an {@link ExponentialMovingAverageRate} for calculating the send rate.
 	 * @param timer a timer.
-	 * @param errorCounter a counter.
+	 * @param errorCounter a counter for sends.
+	 * @param receiveCounter a counter for receives.
+	 * @param receiveErrorCounter a counter for receive errors.
 	 * @since 5.0.2
 	 */
 	public DefaultMessageChannelMetrics(String name, ExponentialMovingAverage sendDuration,
 			ExponentialMovingAverageRate sendErrorRate, ExponentialMovingAverageRatio sendSuccessRatio,
-			ExponentialMovingAverageRate sendRate, Timer timer, Counter errorCounter) {
-		super(name, timer, errorCounter);
+			ExponentialMovingAverageRate sendRate, Timer timer, Counter errorCounter, Counter receiveCounter,
+			Counter receiveErrorCounter) {
+
+		super(name, timer, errorCounter, receiveCounter, receiveErrorCounter);
 		this.sendDuration = sendDuration;
 		this.sendErrorRate = sendErrorRate;
 		this.sendSuccessRatio = sendSuccessRatio;
@@ -251,12 +261,22 @@ public Statistics getErrorRate() {
 
 	@Override
 	public void afterReceive() {
-		this.receiveCount.incrementAndGet();
+		if (getReceiveCounter() != null) {
+			getReceiveCounter().increment();
+		}
+		else {
+			this.receiveCount.incrementAndGet();
+		}
 	}
 
 	@Override
 	public void afterError() {
-		this.receiveErrorCount.incrementAndGet();
+		if (getReceiveErrorCounter() != null) {
+			getReceiveErrorCounter().increment();
+		}
+		else {
+			this.receiveErrorCount.incrementAndGet();
+		}
 	}
 
 	@Override

spring-integration-core/src/main/java/org/springframework/integration/support/management/IntegrationManagementConfigurer.java

@@ -236,7 +236,13 @@ else if (bean instanceof MessageSourceMetrics) {
 
 	@SuppressWarnings("unchecked")
 	private void configureChannelMetrics(String name, MessageChannelMetrics bean) {
-		AbstractMessageChannelMetrics metrics = this.metricsFactory.createChannelMetrics(name);
+		AbstractMessageChannelMetrics metrics;
+		if (bean instanceof PollableChannelManagement) {
+			metrics = this.metricsFactory.createPollableChannelMetrics(name);
+		}
+		else {
+			metrics = this.metricsFactory.createChannelMetrics(name);
+		}
 		Assert.state(metrics != null, "'metrics' must not be null");
 		ManagementOverrides overrides = bean.getOverrides();
 		Boolean enabled = PatternMatchUtils.smartMatch(name, this.enabledCountsPatterns);

spring-integration-core/src/main/java/org/springframework/integration/support/management/MetricsFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2016 the original author or authors.
+ * Copyright 2015-2018 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.integration.support.management;
 
-
 /**
  * Factories implementing this interface provide metric objects for message channels and
  * message handlers.
@@ -34,6 +33,17 @@ public interface MetricsFactory {
 	 */
 	AbstractMessageChannelMetrics createChannelMetrics(String name);
 
+	/**
+	 * Factory method to create an {@link AbstractMessageChannelMetrics} for
+	 * a pollable channel.
+	 * @param name the name.
+	 * @return the metrics.
+	 * @since 5.0.2
+	 */
+	default AbstractMessageChannelMetrics createPollableChannelMetrics(String name) {
+		return createChannelMetrics(name);
+	}
+
 	/**
 	 * Factory method to create an {@link AbstractMessageHandlerMetrics}.
 	 * @param name the name.