Refactor ResponseBodySubscriber to Processor

This commit changes the AbstractResponseBodySubscriber into a
AbstractResponseBodyProcessor<DataBuffer, Void>, so that the processor
can be used as a return value for writeWith.

Additional, this commit no longer closes the response after an eror
occurred.

This fixes #59.

spring-web-reactive/src/test/java/org/springframework/http/server/reactive/ErrorHandlerIntegrationTests.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2002-2016 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.http.server.reactive;
+
+import java.io.IOException;
+import java.net.URI;
+
+import org.junit.Test;
+import reactor.core.publisher.Mono;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.http.server.reactive.boot.ReactorHttpServer;
+import org.springframework.web.client.ResponseErrorHandler;
+import org.springframework.web.client.RestTemplate;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assume.assumeFalse;
+
+/**
+ * @author Arjen Poutsma
+ */
+public class ErrorHandlerIntegrationTests extends AbstractHttpHandlerIntegrationTests {
+
+	private ErrorHandler handler = new ErrorHandler();
+
+	@Override
+	protected HttpHandler createHttpHandler() {
+		return handler;
+	}
+
+	@Test
+	public void response() throws Exception {
+		// TODO: fix Reactor
+		assumeFalse(server instanceof ReactorHttpServer);
+
+		RestTemplate restTemplate = new RestTemplate();
+		restTemplate.setErrorHandler(NO_OP_ERROR_HANDLER);
+
+		ResponseEntity<String> response = restTemplate
+				.getForEntity(new URI("http://localhost:" + port + "/response"),
+						String.class);
+
+		assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, response.getStatusCode());
+	}
+
+	@Test
+	public void returnValue() throws Exception {
+		// TODO: fix Reactor
+		assumeFalse(server instanceof ReactorHttpServer);
+
+		RestTemplate restTemplate = new RestTemplate();
+		restTemplate.setErrorHandler(NO_OP_ERROR_HANDLER);
+
+		ResponseEntity<String> response = restTemplate
+				.getForEntity(new URI("http://localhost:" + port + "/returnValue"),
+						String.class);
+
+		assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, response.getStatusCode());
+	}
+
+	private static class ErrorHandler implements HttpHandler {
+
+		@Override
+		public Mono<Void> handle(ServerHttpRequest request, ServerHttpResponse response) {
+			Exception error = new UnsupportedOperationException();
+			String path = request.getURI().getPath();
+			if (path.endsWith("response")) {
+				return response.writeWith(Mono.error(error));
+			}
+			else if (path.endsWith("returnValue")) {
+				return Mono.error(error);
+			}
+			else {
+				return Mono.empty();
+			}
+		}
+	}
+
+	private static final ResponseErrorHandler NO_OP_ERROR_HANDLER =
+			new ResponseErrorHandler() {
+
+				@Override
+				public boolean hasError(ClientHttpResponse response) throws IOException {
+					return false;
+				}
+
+				@Override
+				public void handleError(ClientHttpResponse response) throws IOException {
+				}
+			};
+
+}

spring-web-reactive/src/test/java/org/springframework/http/server/reactive/RandomHandlerIntegrationTests.java

@@ -21,8 +21,6 @@ import java.util.Random;
 
 import org.junit.Test;
 import org.reactivestreams.Publisher;
-import org.reactivestreams.Subscriber;
-import org.reactivestreams.Subscription;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -31,12 +29,9 @@ import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
-import org.springframework.http.server.reactive.boot.ReactorHttpServer;
 import org.springframework.web.client.RestTemplate;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assume.assumeFalse;
+import static org.junit.Assert.*;
 
 public class RandomHandlerIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
@@ -60,7 +55,6 @@ public class RandomHandlerIntegrationTests extends AbstractHttpHandlerIntegratio
 	@Test
 	public void random() throws Throwable {
 		// TODO: fix Reactor support
-		assumeFalse(server instanceof ReactorHttpServer);
 
 		RestTemplate restTemplate = new RestTemplate();
 
@@ -72,14 +66,6 @@ public class RandomHandlerIntegrationTests extends AbstractHttpHandlerIntegratio
 		assertEquals(RESPONSE_SIZE,
 				response.getHeaders().getContentLength());
 		assertEquals(RESPONSE_SIZE, response.getBody().length);
-
-		while (!handler.requestComplete) {
-			Thread.sleep(100);
-		}
-		if (handler.requestError != null) {
-			throw handler.requestError;
-		}
-		assertEquals(REQUEST_SIZE, handler.requestSize);
 	}
 
 
@@ -93,45 +79,21 @@ public class RandomHandlerIntegrationTests extends AbstractHttpHandlerIntegratio
 
 		public static final int CHUNKS = 16;
 
-		private volatile boolean requestComplete;
-
-		private int requestSize;
-
-		private Throwable requestError;
-
 		@Override
 		public Mono<Void> handle(ServerHttpRequest request, ServerHttpResponse response) {
-			requestError = null;
+			Mono<Integer> requestSizeMono = request.getBody().
+					reduce(0, (integer, dataBuffer) -> integer +
+							dataBuffer.readableByteCount()).
+					doAfterTerminate((size, throwable) -> {
+						assertNull(throwable);
+						assertEquals(REQUEST_SIZE, (long) size);
+					});
 
-			request.getBody().subscribe(new Subscriber<DataBuffer>() {
 
-				@Override
-				public void onSubscribe(Subscription s) {
-					requestComplete = false;
-					requestSize = 0;
-					requestError = null;
-					s.request(Long.MAX_VALUE);
-				}
-
-				@Override
-				public void onNext(DataBuffer bytes) {
-					requestSize += bytes.readableByteCount();
-				}
-
-				@Override
-				public void onError(Throwable t) {
-					requestComplete = true;
-					requestError = t;
-				}
-
-				@Override
-				public void onComplete() {
-					requestComplete = true;
-				}
-			});
 
 			response.getHeaders().setContentLength(RESPONSE_SIZE);
-			return response.writeWith(multipleChunks());
+
+			return requestSizeMono.then(response.writeWith(multipleChunks()));
 		}
 
 		private Publisher<DataBuffer> singleChunk() {