Add ChannelsEndpoint back for introspecting bindings

Bindable picks up 2 new methods to enumerate the binding names, and
then it's a simple matter to list all the inputs and outputs and their
properties.

Fixes gh-149

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/Bindable.java

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.stream.binding;
 
+import java.util.Set;
+
 /**
  * Marker interface for instances that can bind/unbind groups of inputs and outputs.
  *
@@ -45,4 +47,14 @@ public interface Bindable {
 	 */
 	void unbindOutputs(ChannelBindingService adapter);
 
+	/**
+	 * Enumerates all the input binding names.
+	 */
+	Set<String> getInputs();
+
+	/**
+	 * Enumerates all the output binding names.
+	 */
+	Set<String> getOutputs();
+
 }

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/BindableProxyFactory.java

@@ -19,12 +19,12 @@ package org.springframework.cloud.stream.binding;
 import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 
 import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
@@ -102,7 +102,17 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 
 	@Override
 	public void afterPropertiesSet() throws Exception {
-		Assert.notNull(beanFactory, "Bean factory cannot be empty");
+		Assert.notNull(this.beanFactory, "Bean factory cannot be empty");
+	}
+
+	@Override
+	public Set<String> getInputs() {
+		return this.inputs.keySet();
+	}
+
+	@Override
+	public Set<String> getOutputs() {
+		return this.outputs.keySet();
 	}
 
 	private void createChannels(Class<?> type) throws Exception {
@@ -119,11 +129,11 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 					MessageChannel sharedChannel = locateSharedChannel(name);
 					if (sharedChannel == null) {
 						MessageChannel inputChannel = createMessageChannel(inputChannelType);
-						inputs.put(name, new ChannelHolder(inputChannel, true));
+						BindableProxyFactory.this.inputs.put(name, new ChannelHolder(inputChannel, true));
 					}
 					else {
 						if (inputChannelType.isAssignableFrom(sharedChannel.getClass())) {
-							inputs.put(name, new ChannelHolder(sharedChannel, false));
+							BindableProxyFactory.this.inputs.put(name, new ChannelHolder(sharedChannel, false));
 						}
 						else {
 							// handle the special case where the shared channel is of a different nature
@@ -137,7 +147,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 								bridgeSubscribableToPollableChannel(
 										(SubscribableChannel) sharedChannel, inputChannel);
 							}
-							inputs.put(name, new ChannelHolder(inputChannel, false));
+							BindableProxyFactory.this.inputs.put(name, new ChannelHolder(inputChannel, false));
 						}
 					}
 				}
@@ -150,11 +160,11 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 					MessageChannel sharedChannel = locateSharedChannel(name);
 					if (sharedChannel == null) {
 						MessageChannel outputChannel = createMessageChannel(messageChannelType);
-						outputs.put(name, new ChannelHolder(outputChannel, true));
+						BindableProxyFactory.this.outputs.put(name, new ChannelHolder(outputChannel, true));
 					}
 					else {
 						if (messageChannelType.isAssignableFrom(sharedChannel.getClass())) {
-							outputs.put(name, new ChannelHolder(sharedChannel, false));
+							BindableProxyFactory.this.outputs.put(name, new ChannelHolder(sharedChannel, false));
 						}
 						else {
 							// handle the special case where the shared channel is of a different nature
@@ -169,7 +179,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 										(SubscribableChannel) outputChannel,
 										sharedChannel);
 							}
-							outputs.put(name, new ChannelHolder(outputChannel, false));
+							BindableProxyFactory.this.outputs.put(name, new ChannelHolder(outputChannel, false));
 						}
 					}
 				}
@@ -178,11 +188,11 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 	}
 
 	private MessageChannel locateSharedChannel(String name) {
-		return sharedChannelRegistry != null ? sharedChannelRegistry.get(getNamespacePrefixedChannelName(name)) : null;
+		return this.sharedChannelRegistry != null ? this.sharedChannelRegistry.get(getNamespacePrefixedChannelName(name)) : null;
 	}
 
 	private String getNamespacePrefixedChannelName(String name) {
-		return channelNamespace + "." + name;
+		return this.channelNamespace + "." + name;
 	}
 
 	private void bridgeSubscribableToPollableChannel(SubscribableChannel sharedChannel,
@@ -196,12 +206,12 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 		ConsumerEndpointFactoryBean consumerEndpointFactoryBean = new ConsumerEndpointFactoryBean();
 		consumerEndpointFactoryBean.setInputChannel(pollableChannel);
 		PollerMetadata pollerMetadata = new PollerMetadata();
-		pollerMetadata.setTrigger(new PeriodicTrigger(pollableBridgeDefaultFrequency));
+		pollerMetadata.setTrigger(new PeriodicTrigger(this.pollableBridgeDefaultFrequency));
 		consumerEndpointFactoryBean.setPollerMetadata(pollerMetadata);
 		consumerEndpointFactoryBean
 				.setHandler(new MessageChannelBinderSupport.DirectHandler(
 						subscribableChannel));
-		consumerEndpointFactoryBean.setBeanFactory(beanFactory);
+		consumerEndpointFactoryBean.setBeanFactory(this.beanFactory);
 		try {
 			consumerEndpointFactoryBean.afterPropertiesSet();
 		} catch (Exception e) {
@@ -243,7 +253,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 	public synchronized Object getObject() throws Exception {
 		if (this.proxy == null) {
 			createChannels(this.type);
-			ProxyFactory factory = new ProxyFactory(type, this);
+			ProxyFactory factory = new ProxyFactory(this.type, this);
 			this.proxy = factory.getProxy();
 		}
 		return this.proxy;
@@ -264,7 +274,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 		if (log.isDebugEnabled()) {
 			log.debug(String.format("Binding inputs for %s:%s", this.channelNamespace, this.type));
 		}
-		for (Map.Entry<String, ChannelHolder> channelHolderEntry : inputs.entrySet()) {
+		for (Map.Entry<String, ChannelHolder> channelHolderEntry : this.inputs.entrySet()) {
 			String inputChannelName = channelHolderEntry.getKey();
 			ChannelHolder channelHolder = channelHolderEntry.getValue();
 			channelBindingService.configureMessageConverters(channelHolder.getMessageChannel(), inputChannelName);
@@ -282,7 +292,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 		if (log.isDebugEnabled()) {
 			log.debug(String.format("Binding outputs for %s:%s", this.channelNamespace, this.type));
 		}
-		for (Map.Entry<String, ChannelHolder> channelHolderEntry : outputs.entrySet()) {
+		for (Map.Entry<String, ChannelHolder> channelHolderEntry : this.outputs.entrySet()) {
 			ChannelHolder channelHolder = channelHolderEntry.getValue();
 			String outputChannelName = channelHolderEntry.getKey();
 			channelBindingService.configureMessageConverters(channelHolder.getMessageChannel(), outputChannelName);
@@ -300,7 +310,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 		if (log.isDebugEnabled()) {
 			log.debug(String.format("Unbinding inputs for %s:%s", this.channelNamespace, this.type));
 		}
-		for (Map.Entry<String, ChannelHolder> channelHolderEntry : inputs.entrySet()) {
+		for (Map.Entry<String, ChannelHolder> channelHolderEntry : this.inputs.entrySet()) {
 			if (channelHolderEntry.getValue().isBindable()) {
 				if (log.isDebugEnabled()) {
 					log.debug(String.format("Unbinding %s:%s:%s", this.channelNamespace, this.type, channelHolderEntry.getKey()));
@@ -315,7 +325,7 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 		if (log.isDebugEnabled()) {
 			log.debug(String.format("Unbinding outputs for %s:%s", this.channelNamespace, this.type));
 		}
-		for (Map.Entry<String, ChannelHolder> channelHolderEntry : outputs.entrySet()) {
+		for (Map.Entry<String, ChannelHolder> channelHolderEntry : this.outputs.entrySet()) {
 			if (channelHolderEntry.getValue().isBindable()) {
 				if (log.isDebugEnabled()) {
 					log.debug(String.format("Binding %s:%s:%s", this.channelNamespace, this.type, channelHolderEntry.getKey()));
@@ -342,11 +352,11 @@ public class BindableProxyFactory implements MethodInterceptor, FactoryBean<Obje
 		}
 
 		public MessageChannel getMessageChannel() {
-			return messageChannel;
+			return this.messageChannel;
 		}
 
 		public boolean isBindable() {
-			return bindable;
+			return this.bindable;
 		}
 	}
 

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/config/BindingProperties.java

@@ -16,12 +16,16 @@
 
 package org.springframework.cloud.stream.config;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+
 /**
  * Contains the properties of a binding.
  *
  * @author Marius Bogoevici
  * @author Ilayaperumal Gopinathan
  */
+@JsonInclude(value = Include.NON_DEFAULT)
 public class BindingProperties {
 
 	private String destination;
@@ -41,7 +45,7 @@ public class BindingProperties {
 	private String contentType;
 
 	public String getDestination() {
-		return destination;
+		return this.destination;
 	}
 
 	public void setDestination(String destination) {
@@ -49,7 +53,7 @@ public class BindingProperties {
 	}
 
 	public boolean isPartitioned() {
-		return partitioned;
+		return this.partitioned;
 	}
 
 	public void setPartitioned(boolean partitioned) {
@@ -57,7 +61,7 @@ public class BindingProperties {
 	}
 
 	public int getPartitionCount() {
-		return partitionCount;
+		return this.partitionCount;
 	}
 
 	public void setPartitionCount(int partitionCount) {
@@ -65,7 +69,7 @@ public class BindingProperties {
 	}
 
 	public String getPartitionKeyExpression() {
-		return partitionKeyExpression;
+		return this.partitionKeyExpression;
 	}
 
 	public void setPartitionKeyExpression(String partitionKeyExpression) {
@@ -73,7 +77,7 @@ public class BindingProperties {
 	}
 
 	public String getPartitionKeyExtractorClass() {
-		return partitionKeyExtractorClass;
+		return this.partitionKeyExtractorClass;
 	}
 
 	public void setPartitionKeyExtractorClass(String partitionKeyExtractorClass) {
@@ -81,7 +85,7 @@ public class BindingProperties {
 	}
 
 	public String getPartitionSelectorClass() {
-		return partitionSelectorClass;
+		return this.partitionSelectorClass;
 	}
 
 	public void setPartitionSelectorClass(String partitionSelectorClass) {
@@ -89,7 +93,7 @@ public class BindingProperties {
 	}
 
 	public String getPartitionSelectorExpression() {
-		return partitionSelectorExpression;
+		return this.partitionSelectorExpression;
 	}
 
 	public void setPartitionSelectorExpression(String partitionSelectorExpression) {

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/config/ChannelBindingAutoConfiguration.java

@@ -16,11 +16,15 @@
 
 package org.springframework.cloud.stream.config;
 
+import java.util.List;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cloud.stream.binding.Bindable;
 import org.springframework.cloud.stream.binding.ChannelBindingService;
+import org.springframework.cloud.stream.endpoint.ChannelsEndpoint;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.integration.scheduling.PollerMetadata;
@@ -46,4 +50,10 @@ public class ChannelBindingAutoConfiguration {
 		return this.poller.getPollerMetadata();
 	}
 
+	@Bean
+	@Autowired(required=false)
+	public ChannelsEndpoint channelsEndpoint(List<Bindable> adapters, ChannelBindingServiceProperties properties) {
+		return new ChannelsEndpoint(adapters, properties);
+	}
+
 }

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/endpoint/ChannelsEndpoint.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2015 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.stream.endpoint;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.boot.actuate.endpoint.AbstractEndpoint;
+import org.springframework.cloud.stream.binding.Bindable;
+import org.springframework.cloud.stream.config.BindingProperties;
+import org.springframework.cloud.stream.config.ChannelBindingServiceProperties;
+import org.springframework.cloud.stream.endpoint.ChannelsEndpoint.ChannelsMetaData;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+
+/**
+ * @author Dave Syer
+ */
+@RestController
+public class ChannelsEndpoint extends AbstractEndpoint<ChannelsMetaData> {
+
+	private List<Bindable> adapters;
+
+	private ChannelBindingServiceProperties properties;
+
+	public ChannelsEndpoint(List<Bindable> adapters,
+			ChannelBindingServiceProperties properties) {
+		super("channels");
+		this.adapters = adapters;
+		this.properties = properties;
+	}
+
+	@Override
+	public ChannelsMetaData invoke() {
+		ChannelsMetaData map = new ChannelsMetaData();
+		Map<String, BindingProperties> inputs = map.getInputs();
+		Map<String, BindingProperties> outputs = map.getOutputs();
+		for (Bindable factory : this.adapters) {
+			Map<String, BindingProperties> bindings = this.properties.getBindings();
+			for (String name : factory.getInputs()) {
+				inputs.put(name, bindings.containsKey(name) ? bindings.get(name)
+						: new BindingProperties());
+			}
+			for (String name : factory.getOutputs()) {
+				outputs.put(name, bindings.containsKey(name) ? bindings.get(name)
+						: new BindingProperties());
+			}
+		}
+		return map;
+	}
+
+	@JsonInclude(value = Include.NON_DEFAULT)
+	public static class ChannelsMetaData {
+		private Map<String, BindingProperties> inputs = new LinkedHashMap<>();
+		private Map<String, BindingProperties> outputs = new LinkedHashMap<>();
+
+		public Map<String, BindingProperties> getInputs() {
+			return this.inputs;
+		}
+
+		public void setInputs(Map<String, BindingProperties> inputs) {
+			this.inputs = inputs;
+		}
+
+		public Map<String, BindingProperties> getOutputs() {
+			return this.outputs;
+		}
+
+		public void setOutputs(Map<String, BindingProperties> outputs) {
+			this.outputs = outputs;
+		}
+	}
+
+}