Use @EnableModule(Channels.class) instead of field declarations

Standard channel interface types of Sink, Source, Processor
are provided, but user can create others with @Input and
@Output MessageChannel methods.

To get the declared channels in an app you can use the
@ModuleChannels qualifier to inject the interface, e.g.
@ModuleChannels(Cafe.class) injects the channels defined
in the Cafe.

spring-cloud-stream-samples/sink/src/main/java/sink/LogSink.java

@@ -18,25 +18,20 @@ package sink;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
 import org.springframework.cloud.stream.annotation.EnableModule;
-import org.springframework.cloud.stream.annotation.Input;
+import org.springframework.cloud.stream.annotation.Sink;
 import org.springframework.integration.annotation.ServiceActivator;
-import org.springframework.messaging.MessageChannel;
 
 /**
  * @author Dave Syer
  *
  */
-@EnableModule
+@EnableModule(Sink.class)
 public class LogSink {
 
 	private static Logger logger = LoggerFactory.getLogger(LogSink.class);
 
-	@Input
-	public MessageChannel input;
-
-	@ServiceActivator(inputChannel="input")
+	@ServiceActivator(inputChannel=Sink.INPUT)
 	public void loggerSink(Object payload) {
 		logger.info("Received: " + payload);
 	}

spring-cloud-stream-samples/sink/src/test/java/demo/ModuleApplicationTests.java

@@ -1,11 +1,21 @@
 package demo;
 
+import static org.junit.Assert.assertNotNull;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.springframework.test.annotation.DirtiesContext;
-import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.cloud.stream.annotation.ModuleChannels;
+import org.springframework.cloud.stream.annotation.Output;
+import org.springframework.cloud.stream.annotation.Sink;
+import org.springframework.cloud.stream.annotation.Source;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+
+import sink.LogSink;
 
 @RunWith(SpringJUnit4ClassRunner.class)
 @SpringApplicationConfiguration(classes = SinkApplication.class)
@@ -13,8 +23,19 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 @DirtiesContext
 public class ModuleApplicationTests {
 
+	@Autowired
+	@ModuleChannels(LogSink.class)
+	private Sink sink;
+
+	@Autowired
+	private Sink same;
+
+	@Output(Source.OUTPUT)
+	private MessageChannel output;
+
 	@Test
 	public void contextLoads() {
+		assertNotNull(this.sink.input());
 	}
 
 }