Added toString() methods.

org.springframework.integration/src/main/java/org/springframework/integration/endpoint/ServiceActivatingConsumer.java

@@ -77,4 +77,8 @@ public class ServiceActivatingConsumer extends AbstractReplyProducingMessageCons
 		}
 	}
 
+	public String toString() {
+		return "ServiceActivator for [" + this.invoker + "]";
+	}
+
 }

org.springframework.integration/src/main/java/org/springframework/integration/message/MessageMappingMethodInvoker.java

@@ -194,4 +194,8 @@ public class MessageMappingMethodInvoker implements MethodInvoker, InitializingB
 		return new Object[] { message.getPayload() };
 	}
 
+	public String toString() {
+		return "invoker:" + this.object + "." + this.methodName;
+	}
+
 }