Add Spring Integration default poller auto-config

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/integration/IntegrationAutoConfiguration.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.integration;
 
+import java.time.Duration;
+
 import javax.management.MBeanServer;
 import javax.sql.DataSource;
 
@@ -56,10 +58,14 @@
 import org.springframework.integration.rsocket.ServerRSocketConnector;
 import org.springframework.integration.rsocket.ServerRSocketMessageHandler;
 import org.springframework.integration.rsocket.outbound.RSocketOutboundGateway;
+import org.springframework.integration.scheduling.PollerMetadata;
 import org.springframework.messaging.rsocket.RSocketRequester;
 import org.springframework.messaging.rsocket.RSocketStrategies;
 import org.springframework.messaging.rsocket.annotation.support.RSocketMessageHandler;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
+import org.springframework.scheduling.support.CronTrigger;
+import org.springframework.scheduling.support.PeriodicTrigger;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -110,6 +116,29 @@ public static org.springframework.integration.context.IntegrationProperties inte
 	@EnableIntegration
 	protected static class IntegrationConfiguration {
 
+		@Bean(PollerMetadata.DEFAULT_POLLER)
+		@ConditionalOnMissingBean(name = PollerMetadata.DEFAULT_POLLER)
+		public PollerMetadata defaultPoller(IntegrationProperties integrationProperties) {
+			IntegrationProperties.Poller poller = integrationProperties.getPoller();
+			int hasCron = poller.getCron() != null ? 1 : 0;
+			int hasFixedDelay = poller.getFixedDelay() != null ? 1 : 0;
+			int hasFixedRate = poller.getFixedRate() != null ? 1 : 0;
+			Assert.isTrue((hasCron + hasFixedDelay + hasFixedRate) <= 1,
+					"The 'cron', 'fixedDelay' and 'fixedRate' are mutually exclusive 'spring.integration.poller' properties.");
+			PollerMetadata pollerMetadata = new PollerMetadata();
+			PropertyMapper map = PropertyMapper.get().alwaysApplyingWhenNonNull();
+			map.from(poller::getMaxMessagesPerPoll).to(pollerMetadata::setMaxMessagesPerPoll);
+			map.from(poller::getReceiveTimeout).as(Duration::toMillis).to(pollerMetadata::setReceiveTimeout);
+			map.from(poller::getCron).whenHasText().as(CronTrigger::new).to(pollerMetadata::setTrigger);
+			map.from((poller.getFixedDelay() != null) ? poller.getFixedDelay() : poller.getFixedRate())
+					.as(Duration::toMillis).as(PeriodicTrigger::new).as((trigger) -> {
+						map.from(poller::getInitialDelay).as(Duration::toMillis).to(trigger::setInitialDelay);
+						trigger.setFixedRate(poller.getFixedRate() != null);
+						return trigger;
+					}).to(pollerMetadata::setTrigger);
+			return pollerMetadata;
+		}
+
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/integration/IntegrationProperties.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.integration;
 
 import java.net.URI;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -44,6 +45,8 @@ public class IntegrationProperties {
 
 	private final RSocket rsocket = new RSocket();
 
+	private final Poller poller = new Poller();
+
 	public Channel getChannel() {
 		return this.channel;
 	}
@@ -64,6 +67,10 @@ public RSocket getRsocket() {
 		return this.rsocket;
 	}
 
+	public Poller getPoller() {
+		return this.poller;
+	}
+
 	public static class Channel {
 
 		/**
@@ -295,4 +302,88 @@ public void setMessageMappingEnabled(boolean messageMappingEnabled) {
 
 	}
 
+	public static class Poller {
+
+		/**
+		 * Maximum of messages to poll per polling cycle.
+		 */
+		private int maxMessagesPerPoll = Integer.MIN_VALUE; // PollerMetadata.MAX_MESSAGES_UNBOUNDED
+
+		/**
+		 * How long to wait for messages on poll.
+		 */
+		private Duration receiveTimeout = Duration.ofSeconds(1); // PollerMetadata.DEFAULT_RECEIVE_TIMEOUT
+
+		/**
+		 * Polling delay period. Mutually explusive with 'cron' and 'fixedRate'.
+		 */
+		private Duration fixedDelay;
+
+		/**
+		 * Polling rate period. Mutually explusive with 'fixedDelay' and 'cron'.
+		 */
+		private Duration fixedRate;
+
+		/**
+		 * Polling initial delay. Applied for 'fixedDelay' and 'fixedRate'; ignored for
+		 * 'cron'.
+		 */
+		private Duration initialDelay;
+
+		/**
+		 * Cron expression for polling. Mutually explusive with 'fixedDelay' and
+		 * 'fixedRate'.
+		 */
+		private String cron;
+
+		public int getMaxMessagesPerPoll() {
+			return this.maxMessagesPerPoll;
+		}
+
+		public void setMaxMessagesPerPoll(int maxMessagesPerPoll) {
+			this.maxMessagesPerPoll = maxMessagesPerPoll;
+		}
+
+		public Duration getReceiveTimeout() {
+			return this.receiveTimeout;
+		}
+
+		public void setReceiveTimeout(Duration receiveTimeout) {
+			this.receiveTimeout = receiveTimeout;
+		}
+
+		public Duration getFixedDelay() {
+			return this.fixedDelay;
+		}
+
+		public void setFixedDelay(Duration fixedDelay) {
+			this.fixedDelay = fixedDelay;
+		}
+
+		public Duration getFixedRate() {
+			return this.fixedRate;
+		}
+
+		public void setFixedRate(Duration fixedRate) {
+			this.fixedRate = fixedRate;
+		}
+
+		public Duration getInitialDelay() {
+			return this.initialDelay;
+		}
+
+		public void setInitialDelay(Duration initialDelay) {
+			this.initialDelay = initialDelay;
+		}
+
+		public String getCron() {
+			return this.cron;
+		}
+
+		public void setCron(String cron) {
+			this.cron = cron;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/integration/IntegrationAutoConfigurationTests.java

@@ -16,6 +16,10 @@
 
 package org.springframework.boot.autoconfigure.integration;
 
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
 import javax.management.MBeanServer;
 import javax.sql.DataSource;
 
@@ -47,6 +51,8 @@
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.integration.annotation.IntegrationComponentScan;
 import org.springframework.integration.annotation.MessagingGateway;
+import org.springframework.integration.annotation.ServiceActivator;
+import org.springframework.integration.channel.QueueChannel;
 import org.springframework.integration.config.IntegrationManagementConfigurer;
 import org.springframework.integration.context.IntegrationContextUtils;
 import org.springframework.integration.core.MessageSource;
@@ -57,13 +63,17 @@
 import org.springframework.integration.rsocket.IntegrationRSocketEndpoint;
 import org.springframework.integration.rsocket.ServerRSocketConnector;
 import org.springframework.integration.rsocket.ServerRSocketMessageHandler;
+import org.springframework.integration.scheduling.PollerMetadata;
 import org.springframework.integration.support.channel.HeaderChannelRegistry;
 import org.springframework.jdbc.BadSqlGrammarException;
 import org.springframework.jdbc.core.JdbcOperations;
 import org.springframework.jmx.export.MBeanExporter;
 import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHandler;
 import org.springframework.messaging.rsocket.annotation.support.RSocketMessageHandler;
+import org.springframework.messaging.support.GenericMessage;
 import org.springframework.scheduling.TaskScheduler;
+import org.springframework.scheduling.support.CronTrigger;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
@@ -372,6 +382,54 @@ void whenTheUserDefinesTheirOwnDatabaseInitializerThenTheAutoConfiguredIntegrati
 						.hasBean("customInitializer"));
 	}
 
+	@Test
+	void defaultPoller() {
+		this.contextRunner.withUserConfiguration(PollingConsumerConfiguration.class).run((context) -> {
+			assertThat(context).hasSingleBean(PollerMetadata.class).getBean(PollerMetadata.DEFAULT_POLLER)
+					.hasFieldOrPropertyWithValue("maxMessagesPerPoll", (long) PollerMetadata.MAX_MESSAGES_UNBOUNDED)
+					.hasFieldOrPropertyWithValue("receiveTimeout", PollerMetadata.DEFAULT_RECEIVE_TIMEOUT)
+					.hasFieldOrPropertyWithValue("trigger", null);
+
+			GenericMessage<String> testMessage = new GenericMessage<>("test");
+			context.getBean("testChannel", QueueChannel.class).send(testMessage);
+			@SuppressWarnings("unchecked")
+			BlockingQueue<Message<?>> sink = context.getBean("sink", BlockingQueue.class);
+			assertThat(sink.poll(10, TimeUnit.SECONDS)).isSameAs(testMessage);
+		});
+	}
+
+	@Test
+	void customPollerProperties() {
+		this.contextRunner.withUserConfiguration(PollingConsumerConfiguration.class)
+				.withPropertyValues("spring.integration.poller.cron=* * * ? * *",
+						"spring.integration.poller.max-messages-per-poll=1",
+						"spring.integration.poller.receive-timeout=10s")
+				.run((context) -> {
+					assertThat(context).hasSingleBean(PollerMetadata.class)
+							.getBean(PollerMetadata.DEFAULT_POLLER, PollerMetadata.class)
+							.hasFieldOrPropertyWithValue("maxMessagesPerPoll", 1L)
+							.hasFieldOrPropertyWithValue("receiveTimeout", 10000L)
+							.extracting(PollerMetadata::getTrigger).isInstanceOf(CronTrigger.class)
+							.hasFieldOrPropertyWithValue("expression", "* * * ? * *");
+
+					GenericMessage<String> testMessage = new GenericMessage<>("test");
+					context.getBean("testChannel", QueueChannel.class).send(testMessage);
+					@SuppressWarnings("unchecked")
+					BlockingQueue<Message<?>> sink = context.getBean("sink", BlockingQueue.class);
+					assertThat(sink.poll(10, TimeUnit.SECONDS)).isSameAs(testMessage);
+				});
+	}
+
+	@Test
+	void triggerPropertiesAreMutuallyExclusive() {
+		this.contextRunner
+				.withPropertyValues("spring.integration.poller.cron=* * * ? * *",
+						"spring.integration.poller.fixed-delay=1s")
+				.run((context) -> assertThat(context).hasFailed().getFailure()
+						.hasRootCauseExactlyInstanceOf(IllegalArgumentException.class).hasMessageContaining(
+								"The 'cron', 'fixedDelay' and 'fixedRate' are mutually exclusive 'spring.integration.poller' properties."));
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class CustomMBeanExporter {
 
@@ -459,4 +517,25 @@ IntegrationDataSourceInitializer customInitializer(DataSource dataSource, Resour
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class PollingConsumerConfiguration {
+
+		@Bean
+		QueueChannel testChannel() {
+			return new QueueChannel();
+		}
+
+		@Bean
+		BlockingQueue<Message<?>> sink() {
+			return new LinkedBlockingQueue<>();
+		}
+
+		@ServiceActivator(inputChannel = "testChannel")
+		@Bean
+		MessageHandler handler(BlockingQueue<Message<?>> sink) {
+			return sink::add;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-docs/src/docs/asciidoc/messaging/spring-integration.adoc

@@ -5,6 +5,7 @@ Spring Integration provides abstractions over messaging and also other transport
 If Spring Integration is available on your classpath, it is initialized through the `@EnableIntegration` annotation.
 
 Spring Integration polling logic relies <<features#features.task-execution-and-scheduling,on the auto-configured `TaskScheduler`>>.
+The default `PollerMetadata` (poll unbounded number of messages every second) can be customized with `spring.integration.poller.*` configuration properties.
 
 Spring Boot also configures some features that are triggered by the presence of additional Spring Integration modules.
 If `spring-integration-jmx` is also on the classpath, message processing statistics are published over JMX.