Add ability to customize message channels

@EnableWebSocketMessageBroker message channel configuration can now be
customized via WebSocketMessageBrokerConfigurer. It is necessary to
make this easy and even required as part of the basic configuration
since by default the message channels are backed by a thread pool of
size 1, not suitable for production use.

Issue: SPR-11023

spring-messaging/src/test/java/org/springframework/messaging/simp/config/MessageBrokerConfigurationTests.java

@@ -36,13 +36,17 @@ import org.springframework.messaging.simp.stomp.StompCommand;
 import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
 import org.springframework.messaging.support.MessageBuilder;
 import org.springframework.messaging.support.channel.AbstractSubscribableChannel;
+import org.springframework.messaging.support.channel.ChannelInterceptor;
+import org.springframework.messaging.support.channel.ChannelInterceptorAdapter;
 import org.springframework.messaging.support.channel.ExecutorSubscribableChannel;
 import org.springframework.messaging.support.converter.CompositeMessageConverter;
 import org.springframework.messaging.support.converter.DefaultContentTypeResolver;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 import org.springframework.stereotype.Controller;
 import org.springframework.util.MimeTypeUtils;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import static org.junit.Assert.*;
@@ -59,6 +63,8 @@ public class MessageBrokerConfigurationTests {
 
 	private AnnotationConfigApplicationContext cxtStompBroker;
 
+	private AnnotationConfigApplicationContext cxtCustomizedChannelConfig;
+
 
 	@Before
 	public void setupOnce() {
@@ -70,6 +76,10 @@ public class MessageBrokerConfigurationTests {
 		this.cxtStompBroker = new AnnotationConfigApplicationContext();
 		this.cxtStompBroker.register(TestStompMessageBrokerConfig.class);
 		this.cxtStompBroker.refresh();
+
+		this.cxtCustomizedChannelConfig = new AnnotationConfigApplicationContext();
+		this.cxtCustomizedChannelConfig.register(CustomizedChannelConfig.class);
+		this.cxtCustomizedChannelConfig.refresh();
 	}
 
 
@@ -96,6 +106,22 @@ public class MessageBrokerConfigurationTests {
 		assertTrue(values.contains(cxtStompBroker.getBean(StompBrokerRelayMessageHandler.class)));
 	}
 
+	@Test
+	public void clientInboundChannelCustomized() {
+
+		AbstractSubscribableChannel channel = this.cxtCustomizedChannelConfig.getBean(
+				"clientInboundChannel", AbstractSubscribableChannel.class);
+
+		assertEquals(1, channel.getInterceptors().size());
+
+		ThreadPoolTaskExecutor taskExecutor = this.cxtCustomizedChannelConfig.getBean(
+				"clientInboundChannelExecutor", ThreadPoolTaskExecutor.class);
+
+		assertEquals(11, taskExecutor.getCorePoolSize());
+		assertEquals(12, taskExecutor.getMaxPoolSize());
+		assertEquals(13, taskExecutor.getKeepAliveSeconds());
+	}
+
 	@Test
 	public void clientOutboundChannelUsedByAnnotatedMethod() {
 
@@ -148,6 +174,22 @@ public class MessageBrokerConfigurationTests {
 		assertEquals("bar", new String((byte[]) message.getPayload()));
 	}
 
+	@Test
+	public void clientOutboundChannelCustomized() {
+
+		AbstractSubscribableChannel channel = this.cxtCustomizedChannelConfig.getBean(
+				"clientOutboundChannel", AbstractSubscribableChannel.class);
+
+		assertEquals(2, channel.getInterceptors().size());
+
+		ThreadPoolTaskExecutor taskExecutor = this.cxtCustomizedChannelConfig.getBean(
+				"clientOutboundChannelExecutor", ThreadPoolTaskExecutor.class);
+
+		assertEquals(21, taskExecutor.getCorePoolSize());
+		assertEquals(22, taskExecutor.getMaxPoolSize());
+		assertEquals(23, taskExecutor.getKeepAliveSeconds());
+	}
+
 	@Test
 	public void brokerChannel() {
 		TestChannel channel = this.cxtSimpleBroker.getBean("brokerChannel", TestChannel.class);
@@ -207,6 +249,22 @@ public class MessageBrokerConfigurationTests {
 		assertEquals("/foo-users1", headers.getDestination());
 	}
 
+	@Test
+	public void brokerChannelCustomized() {
+
+		AbstractSubscribableChannel channel = this.cxtCustomizedChannelConfig.getBean(
+				"brokerChannel", AbstractSubscribableChannel.class);
+
+		assertEquals(3, channel.getInterceptors().size());
+
+		ThreadPoolTaskExecutor taskExecutor = this.cxtCustomizedChannelConfig.getBean(
+				"brokerChannelExecutor", ThreadPoolTaskExecutor.class);
+
+		assertEquals(31, taskExecutor.getCorePoolSize());
+		assertEquals(32, taskExecutor.getMaxPoolSize());
+		assertEquals(33, taskExecutor.getKeepAliveSeconds());
+	}
+
 	@Test
 	public void messageConverter() {
 		CompositeMessageConverter messageConverter = this.cxtStompBroker.getBean(
@@ -240,9 +298,6 @@ public class MessageBrokerConfigurationTests {
 			return new TestController();
 		}
 
-		@Override
-		protected void configureMessageBroker(MessageBrokerRegistry registry) {
-		}
 
 		@Override
 		@Bean
@@ -250,16 +305,29 @@ public class MessageBrokerConfigurationTests {
 			return new TestChannel();
 		}
 
+		@Override
+		protected void configureClientInboundChannel(ChannelRegistration registration) {
+		}
+
 		@Override
 		@Bean
 		public AbstractSubscribableChannel clientOutboundChannel() {
 			return new TestChannel();
 		}
 
+		@Override
+		protected void configureClientOutboundChannel(ChannelRegistration registration) {
+		}
+
 		@Override
 		public AbstractSubscribableChannel brokerChannel() {
 			return new TestChannel();
 		}
+
+		@Override
+		protected void configureMessageBroker(MessageBrokerRegistry registry) {
+		}
+
 	}
 
 	@Configuration
@@ -271,6 +339,32 @@ public class MessageBrokerConfigurationTests {
 		}
 	}
 
+	@Configuration
+	static class CustomizedChannelConfig extends AbstractMessageBrokerConfiguration {
+
+		private ChannelInterceptor interceptor = new ChannelInterceptorAdapter();
+
+
+		@Override
+		protected void configureClientInboundChannel(ChannelRegistration registration) {
+			registration.setInterceptors(this.interceptor);
+			registration.taskExecutor().corePoolSize(11).maxPoolSize(12).keepAliveSeconds(13).queueCapacity(14);
+		}
+
+		@Override
+		protected void configureClientOutboundChannel(ChannelRegistration registration) {
+			registration.setInterceptors(this.interceptor, this.interceptor);
+			registration.taskExecutor().corePoolSize(21).maxPoolSize(22).keepAliveSeconds(23).queueCapacity(24);
+		}
+
+		@Override
+		protected void configureMessageBroker(MessageBrokerRegistry registry) {
+			registry.configureBrokerChannel().setInterceptors(this.interceptor, this.interceptor, this.interceptor);
+			registry.configureBrokerChannel().taskExecutor()
+					.corePoolSize(31).maxPoolSize(32).keepAliveSeconds(33).queueCapacity(34);
+		}
+	}
+
 
 	private static class TestChannel extends ExecutorSubscribableChannel {