Impl CoreSubscriber instead of Subscriber

According Reactor recommendation it would be better to `CoreSubscriber`
from Reactor instead of Reactive Streams `Subscriber` for chasing
some optimisation in case of Reactor flows

Increase `receive()` timeout in the `AttributePollingChannelAdapterParserTests`

spring-integration-core/src/main/java/org/springframework/integration/endpoint/ReactiveStreamsConsumer.java

@@ -34,6 +34,7 @@ import org.springframework.messaging.MessageHandler;
 import org.springframework.util.Assert;
 import org.springframework.util.ErrorHandler;
 
+import reactor.core.CoreSubscriber;
 import reactor.core.Disposable;
 import reactor.core.publisher.BaseSubscriber;
 
@@ -165,7 +166,7 @@ public class ReactiveStreamsConsumer extends AbstractEndpoint implements Integra
 
 
 	private static final class MessageHandlerSubscriber
-			implements Subscriber<Message<?>>, Disposable, Lifecycle {
+			implements CoreSubscriber<Message<?>>, Disposable, Lifecycle {
 
 		private final Consumer<Message<?>> consumer;
 

spring-integration-core/src/main/java/org/springframework/integration/handler/AbstractMessageHandler.java

@@ -16,7 +16,6 @@
 
 package org.springframework.integration.handler;
 
-import org.reactivestreams.Subscriber;
 import org.reactivestreams.Subscription;
 
 import org.springframework.core.Ordered;
@@ -37,6 +36,8 @@ import org.springframework.messaging.MessageHandlingException;
 import org.springframework.messaging.MessagingException;
 import org.springframework.util.Assert;
 
+import reactor.core.CoreSubscriber;
+
 /**
  * Base class for MessageHandler implementations that provides basic validation
  * and error handling capabilities. Asserts that the incoming Message is not
@@ -50,7 +51,7 @@ import org.springframework.util.Assert;
 @IntegrationManagedResource
 public abstract class AbstractMessageHandler extends IntegrationObjectSupport implements MessageHandler,
 		MessageHandlerMetrics, ConfigurableMetricsAware<AbstractMessageHandlerMetrics>, TrackableComponent, Orderable,
-		Subscriber<Message<?>> {
+		CoreSubscriber<Message<?>> {
 
 	private volatile boolean shouldTrack = false;
 

spring-integration-jmx/src/test/java/org/springframework/integration/jmx/config/AttributePollingChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -37,6 +37,7 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 /**
  * @author Mark Fisher
  * @author Gary Russell
+ *
  * @since 2.0
  */
 @ContextConfiguration
@@ -56,21 +57,22 @@ public class AttributePollingChannelAdapterParserTests {
 	@Autowired
 	private MessageChannel autoChannel;
 
-	@Autowired @Qualifier("autoChannel.adapter")
+	@Autowired
+	@Qualifier("autoChannel.adapter")
 	private SourcePollingChannelAdapter autoChannelAdapter;
 
 	@Test
 	public void pollForAttribute() throws Exception {
-		testBean.test("foo");
-		adapter.start();
-		Message<?> result = channel.receive(1000);
+		this.testBean.test("foo");
+		this.adapter.start();
+		Message<?> result = this.channel.receive(10000);
 		assertNotNull(result);
 		assertEquals("foo", result.getPayload());
 	}
 
 	@Test
 	public void testAutoChannel() {
-		assertSame(autoChannel, TestUtils.getPropertyValue(autoChannelAdapter, "outputChannel"));
+		assertSame(this.autoChannel, TestUtils.getPropertyValue(this.autoChannelAdapter, "outputChannel"));
 	}
 
 }