Remove Stream#toBlockingQueue use

spring-web-reactive/src/main/java/org/springframework/core/io/buffer/support/DataBufferPublisherInputStream.java

@@ -18,12 +18,12 @@ package org.springframework.core.io.buffer.support;
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.concurrent.BlockingQueue;
+import java.util.Iterator;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.reactivestreams.Publisher;
 import org.reactivestreams.Subscription;
-import reactor.rx.Stream;
+import reactor.core.publisher.Flux;
 
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.util.Assert;
@@ -35,7 +35,7 @@ class DataBufferPublisherInputStream extends InputStream {
 
 	private final AtomicBoolean completed = new AtomicBoolean();
 
-	private final BlockingQueue<DataBuffer> queue;
+	private final Iterator<DataBuffer> queue;
 
 	private InputStream currentStream;
 
@@ -57,8 +57,7 @@ class DataBufferPublisherInputStream extends InputStream {
 			int requestSize) {
 		Assert.notNull(publisher, "'publisher' must not be null");
 
-		// TODO Avoid using Reactor Stream, it should not be a mandatory dependency of Spring Reactive
+		this.queue = Flux.from(publisher).toIterable(requestSize).iterator();
-		this.queue = Stream.from(publisher).toBlockingQueue(requestSize);
 	}
 
 	@Override
@@ -126,25 +125,22 @@ class DataBufferPublisherInputStream extends InputStream {
 				return this.currentStream;
 			}
 			else {
-				// take() blocks until next or complete() then return null,
+				// if upstream Publisher has completed, then complete() and return null,
-				// but that's OK since this is a *blocking* InputStream
+				if (!this.queue.hasNext()) {
-				DataBuffer signal = this.queue.take();
-				if (signal == null) {
 					this.completed.set(true);
 					return null;
 				}
+				// next() blocks until next
+				// but that's OK since this is a *blocking* InputStream
+				DataBuffer signal = this.queue.next();
 				this.currentStream = signal.asInputStream();
 				return this.currentStream;
 			}
 		}
-		catch (InterruptedException ex) {
-			Thread.currentThread().interrupt();
-		}
 		catch (Throwable error) {
 			this.completed.set(true);
 			throw new IOException(error);
 		}
-		throw new IOException();
 	}