Adds JMX Operations to Bus Endpoints (#52)

Adds @ManagedResource and @ManagedOperation to
the EnvironmentBusEndpoint and RefreshBusEndpoint
to expose these operations over JMX.

Fixes gh-50

spring-cloud-bus/src/main/java/org/springframework/cloud/bus/endpoint/EnvironmentBusEndpoint.java

@@ -4,6 +4,8 @@
 
 import org.springframework.cloud.bus.event.EnvironmentChangeRemoteApplicationEvent;
 import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.jmx.export.annotation.ManagedOperation;
+import org.springframework.jmx.export.annotation.ManagedResource;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -12,6 +14,7 @@
 /**
  * @author Spencer Gibb
  */
+@ManagedResource
 public class EnvironmentBusEndpoint extends AbstractBusEndpoint {
 
 	public EnvironmentBusEndpoint(ApplicationEventPublisher context, String id,
@@ -21,6 +24,7 @@ public EnvironmentBusEndpoint(ApplicationEventPublisher context, String id,
 
 	@RequestMapping(value = "env", method = RequestMethod.POST)
 	@ResponseBody
+	@ManagedOperation
 	// TODO: make this an abstract method in AbstractBusEndpoint?
 	public void env(@RequestParam Map<String, String> params,
 			@RequestParam(value = "destination", required = false) String destination) {

spring-cloud-bus/src/main/java/org/springframework/cloud/bus/endpoint/RefreshBusEndpoint.java

@@ -2,6 +2,9 @@
 
 import org.springframework.cloud.bus.event.RefreshRemoteApplicationEvent;
 import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.jmx.export.annotation.ManagedOperation;
+import org.springframework.jmx.export.annotation.ManagedOperationParameter;
+import org.springframework.jmx.export.annotation.ManagedResource;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -10,6 +13,7 @@
 /**
  * @author Spencer Gibb
  */
+@ManagedResource
 public class RefreshBusEndpoint extends AbstractBusEndpoint {
 
 	public RefreshBusEndpoint(ApplicationEventPublisher context, String id,
@@ -19,6 +23,7 @@ public RefreshBusEndpoint(ApplicationEventPublisher context, String id,
 
 	@RequestMapping(value = "refresh", method = RequestMethod.POST)
 	@ResponseBody
+	@ManagedOperation
 	public void refresh(
 			@RequestParam(value = "destination", required = false) String destination) {
 		publish(new RefreshRemoteApplicationEvent(this, getInstanceId(), destination));