Polish

Also remove ErrorDeferredResultProcessingInterceptor which was meant
to be package private to begin with as its peer
ErrorCallableProcessingInterceptor (also removed).

spring-web/src/main/java/org/springframework/web/context/request/async/DeferredResultInterceptorChain.java

@@ -82,17 +82,22 @@ class DeferredResultInterceptorChain {
 		}
 	}
 
-	public void triggerAfterError(NativeWebRequest request, DeferredResult<?> deferredResult, Throwable ex)
+	/**
+	 * @return true to continue error handling, or false to bypass any further
+	 * error handling
+	 */
+	public boolean triggerAfterError(NativeWebRequest request, DeferredResult<?> deferredResult, Throwable ex)
 			throws Exception {
 
 		for (DeferredResultProcessingInterceptor interceptor : this.interceptors) {
 			if (deferredResult.isSetOrExpired()) {
-				return;
+				return false;
 			}
 			if (!interceptor.handleError(request, deferredResult, ex)){
-				break;
+				return false;
 			}
 		}
+		return true;
 	}
 
 	public void triggerAfterCompletion(NativeWebRequest request, DeferredResult<?> deferredResult) {

spring-web/src/main/java/org/springframework/web/context/request/async/DeferredResultProcessingInterceptor.java

@@ -114,8 +114,8 @@ public interface DeferredResultProcessingInterceptor {
 	 * {@code DeferredResult} is set, then concurrent processing is resumed and
 	 * subsequent interceptors are not invoked
 	 * @param t the error that occurred while request processing
-	 * @return {@code true} if processing should continue, or {@code false} if
-	 * other interceptors should not be invoked
+	 * @return {@code true} if error handling should continue, or {@code false} if
+	 * other interceptors should by bypassed and not be invoked
 	 * @throws Exception in case of errors
 	 */
 	default <T> boolean handleError(NativeWebRequest request, DeferredResult<T> deferredResult,

spring-web/src/main/java/org/springframework/web/context/request/async/ErrorCallableProcessingInterceptor.java

@@ -1,37 +0,0 @@
-/*
- * Copyright 2002-2017 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.web.context.request.async;
-
-import java.util.concurrent.Callable;
-
-import org.springframework.web.context.request.NativeWebRequest;
-
-/**
- * Registered at the end, after all other interceptors and
- * therefore invoked only if no other interceptor handles the error.
- *
- * @author Violeta Georgieva
- * @since 5.0
- */
-class ErrorCallableProcessingInterceptor implements CallableProcessingInterceptor {
-
-	@Override
-	public <T> Object handleError(NativeWebRequest request, Callable<T> task, Throwable t) throws Exception {
-		return t;
-	}
-
-}

spring-web/src/main/java/org/springframework/web/context/request/async/ErrorDeferredResultProcessingInterceptor.java

@@ -1,38 +0,0 @@
-/*
- * Copyright 2002-2017 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.web.context.request.async;
-
-import org.springframework.web.context.request.NativeWebRequest;
-
-/**
- * Registered at the end, after all other interceptors and
- * therefore invoked only if no other interceptor handles the error.
- *
- * @author Violeta Georgieva
- * @since 5.0
- */
-public class ErrorDeferredResultProcessingInterceptor implements DeferredResultProcessingInterceptor {
-
-	@Override
-	public <T> boolean handleError(NativeWebRequest request, DeferredResult<T> result, Throwable t)
-			throws Exception {
-
-		result.setErrorResult(t);
-		return false;
-	}
-
-}

spring-web/src/main/java/org/springframework/web/context/request/async/WebAsyncManager.java

@@ -68,15 +68,9 @@ public final class WebAsyncManager {
 	private static final CallableProcessingInterceptor timeoutCallableInterceptor =
 			new TimeoutCallableProcessingInterceptor();
 
-	private static final CallableProcessingInterceptor errorCallableInterceptor =
-			new ErrorCallableProcessingInterceptor();
-
 	private static final DeferredResultProcessingInterceptor timeoutDeferredResultInterceptor =
 			new TimeoutDeferredResultProcessingInterceptor();
 
-	private static final DeferredResultProcessingInterceptor errorDeferredResultInterceptor =
-			new ErrorDeferredResultProcessingInterceptor();
-
 
 	private AsyncWebRequest asyncWebRequest;
 
@@ -290,7 +284,6 @@ public final class WebAsyncManager {
 		interceptors.add(webAsyncTask.getInterceptor());
 		interceptors.addAll(this.callableInterceptors.values());
 		interceptors.add(timeoutCallableInterceptor);
-		interceptors.add(errorCallableInterceptor);
 
 		final Callable<?> callable = webAsyncTask.getCallable();
 		final CallableInterceptorChain interceptorChain = new CallableInterceptorChain(interceptors);
@@ -303,12 +296,11 @@ public final class WebAsyncManager {
 			}
 		});
 
-		this.asyncWebRequest.addErrorHandler(t -> {
+		this.asyncWebRequest.addErrorHandler(ex -> {
 			logger.debug("Processing error");
-			Object result = interceptorChain.triggerAfterError(this.asyncWebRequest, callable, t);
-			if (result != CallableProcessingInterceptor.RESULT_NONE) {
-				setConcurrentResultAndDispatch(result);
-			}
+			Object result = interceptorChain.triggerAfterError(this.asyncWebRequest, callable, ex);
+			result = (result != CallableProcessingInterceptor.RESULT_NONE ? result : ex);
+			setConcurrentResultAndDispatch(result);
 		});
 
 		this.asyncWebRequest.addCompletionHandler(() ->
@@ -390,7 +382,6 @@ public final class WebAsyncManager {
 		interceptors.add(deferredResult.getInterceptor());
 		interceptors.addAll(this.deferredResultInterceptors.values());
 		interceptors.add(timeoutDeferredResultInterceptor);
-		interceptors.add(errorDeferredResultInterceptor);
 
 		final DeferredResultInterceptorChain interceptorChain = new DeferredResultInterceptorChain(interceptors);
 
@@ -403,12 +394,15 @@ public final class WebAsyncManager {
 			}
 		});
 
-		this.asyncWebRequest.addErrorHandler(t -> {
+		this.asyncWebRequest.addErrorHandler(ex -> {
 			try {
-				interceptorChain.triggerAfterError(this.asyncWebRequest, deferredResult, t);
+				if (!interceptorChain.triggerAfterError(this.asyncWebRequest, deferredResult, ex)) {
+					return;
+				}
+				deferredResult.setErrorResult(ex);
 			}
-			catch (Throwable ex) {
-				setConcurrentResultAndDispatch(ex);
+			catch (Throwable interceptorEx) {
+				setConcurrentResultAndDispatch(interceptorEx);
 			}
 		});