Sync BaseSubscriber

spring-web-reactive/src/main/java/org/springframework/http/server/reactive/UndertowHttpHandlerAdapter.java

@@ -320,8 +320,8 @@ public class UndertowHttpHandlerAdapter implements io.undertow.server.HttpHandle
 		}
 	}
 
-	private static class ResponseBodySubscriber extends BaseSubscriber<DataBuffer>
-			implements ChannelListener<StreamSinkChannel> {
+	private static class ResponseBodySubscriber
+			implements ChannelListener<StreamSinkChannel>, BaseSubscriber<DataBuffer>{
 
 		private final HttpServerExchange exchange;
 
@@ -342,14 +342,14 @@ public class UndertowHttpHandlerAdapter implements io.undertow.server.HttpHandle
 
 		@Override
 		public void onSubscribe(Subscription subscription) {
-			super.onSubscribe(subscription);
+			BaseSubscriber.super.onSubscribe(subscription);
 			this.subscription = subscription;
 			this.subscription.request(1);
 		}
 
 		@Override
 		public void onNext(DataBuffer dataBuffer) {
-			super.onNext(dataBuffer);
+			BaseSubscriber.super.onNext(dataBuffer);
 
 			ByteBuffer buffer = dataBuffer.asByteBuffer();
 
@@ -439,7 +439,7 @@ public class UndertowHttpHandlerAdapter implements io.undertow.server.HttpHandle
 
 		@Override
 		public void onError(Throwable ex) {
-			super.onError(ex);
+			BaseSubscriber.super.onError(ex);
 			logger.error("ResponseBodySubscriber error", ex);
 			if (!exchange.isResponseStarted() && exchange.getStatusCode() < 500) {
 				exchange.setStatusCode(500);
@@ -448,7 +448,6 @@ public class UndertowHttpHandlerAdapter implements io.undertow.server.HttpHandle
 
 		@Override
 		public void onComplete() {
-			super.onComplete();
 			if (this.responseChannel != null) {
 				this.closing.set(true);
 				closeIfDone();