diff --git a/spring-web/src/main/java/org/springframework/web/context/request/async/AsyncWebRequest.java b/spring-web/src/main/java/org/springframework/web/context/request/async/AsyncWebRequest.java
index 1e89d1a2fc..9cf4fda6f0 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/async/AsyncWebRequest.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/async/AsyncWebRequest.java
@@ -46,6 +46,7 @@ public interface AsyncWebRequest extends NativeWebRequest {
 	/**
 	 * Add a handler to invoke when an error occurred while concurrent
 	 * handling of a request.
+	 * @since 5.0
 	 */
 	void addErrorHandler(Consumer<Throwable> exceptionHandler);
 
diff --git a/spring-web/src/main/java/org/springframework/web/context/request/async/CallableProcessingInterceptor.java b/spring-web/src/main/java/org/springframework/web/context/request/async/CallableProcessingInterceptor.java
index 8b6fba962d..4a43b4526c 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/async/CallableProcessingInterceptor.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/async/CallableProcessingInterceptor.java
@@ -102,17 +102,18 @@ public interface CallableProcessingInterceptor {
 	<T> Object handleTimeout(NativeWebRequest request, Callable<T> task) throws Exception;
 
 	/**
-	 * Invoked from a container thread when an error occurred while processing the async request
-	 * before the {@code Callable} task completes. Implementations may return a value,
-	 * including an {@link Exception}, to use instead of the value the
-	 * {@link Callable} did not return in time.
+	 * Invoked from a container thread when an error occurred while processing
+	 * the async request before the {@code Callable} task completes.
+	 * Implementations may return a value, including an {@link Exception}, to
+	 * use instead of the value the {@link Callable} did not return in time.
 	 * @param request the current request
 	 * @param task the task for the current async request
-	 * @paramt t the error that occurred while request processing
+	 * @param t the error that occurred while request processing
 	 * @return a concurrent result value; if the value is anything other than
 	 * {@link #RESULT_NONE} or {@link #RESPONSE_HANDLED}, concurrent processing
 	 * is resumed and subsequent interceptors are not invoked
 	 * @throws Exception in case of errors
+	 * @since 5.0
 	 */
 	<T> Object handleError(NativeWebRequest request, Callable<T> task, Throwable t) throws Exception;
 
diff --git a/spring-web/src/main/java/org/springframework/web/context/request/async/DeferredResult.java b/spring-web/src/main/java/org/springframework/web/context/request/async/DeferredResult.java
index 8667871d34..0d5b76086d 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/async/DeferredResult.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/async/DeferredResult.java
@@ -154,11 +154,13 @@ public class DeferredResult<T> {
 	}
 
 	/**
-	 * Register code to invoke when an error occurred while processing the async request.
-	 * <p>This method is called from a container thread when  an error occurred while
-	 * processing an async request before the {@code DeferredResult} has been populated.
-	 * It may invoke {@link DeferredResult#setResult setResult} or
-	 * {@link DeferredResult#setErrorResult setErrorResult} to resume processing.
+	 * Register code to invoke when an error occurred during the async request.
+	 * <p>This method is called from a container thread when an error occurs
+	 * while processing an async request before the {@code DeferredResult} has
+	 * been populated. It may invoke {@link DeferredResult#setResult setResult}
+	 * or {@link DeferredResult#setErrorResult setErrorResult} to resume
+	 * processing.
+	 * @since 5.0
 	 */
 	public void onError(Consumer<Throwable> callback) {
 		this.errorCallback = callback;
diff --git a/spring-web/src/main/java/org/springframework/web/context/request/async/ErrorCallableProcessingInterceptor.java b/spring-web/src/main/java/org/springframework/web/context/request/async/ErrorCallableProcessingInterceptor.java
index 2f7b7f80ca..a8cffce575 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/async/ErrorCallableProcessingInterceptor.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/async/ErrorCallableProcessingInterceptor.java
@@ -27,7 +27,7 @@ import org.springframework.web.context.request.NativeWebRequest;
  * @author Violeta Georgieva
  * @since 5.0
  */
-public class ErrorCallableProcessingInterceptor extends CallableProcessingInterceptorAdapter {
+class ErrorCallableProcessingInterceptor extends CallableProcessingInterceptorAdapter {
 
 	@Override
 	public <T> Object handleError(NativeWebRequest request, Callable<T> task, Throwable t) throws Exception {
diff --git a/spring-web/src/main/java/org/springframework/web/context/request/async/StandardServletAsyncWebRequest.java b/spring-web/src/main/java/org/springframework/web/context/request/async/StandardServletAsyncWebRequest.java
index dadb0fea31..31d2311121 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/async/StandardServletAsyncWebRequest.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/async/StandardServletAsyncWebRequest.java
@@ -143,23 +143,17 @@ public class StandardServletAsyncWebRequest extends ServletWebRequest implements
 
 	@Override
 	public void onError(AsyncEvent event) throws IOException {
-		for (Consumer<Throwable> handler : this.exceptionHandlers) {
-			handler.accept(event.getThrowable());
-		}
+		this.exceptionHandlers.forEach(consumer -> consumer.accept(event.getThrowable()));
 	}
 
 	@Override
 	public void onTimeout(AsyncEvent event) throws IOException {
-		for (Runnable handler : this.timeoutHandlers) {
-			handler.run();
-		}
+		this.timeoutHandlers.forEach(Runnable::run);
 	}
 
 	@Override
 	public void onComplete(AsyncEvent event) throws IOException {
-		for (Runnable handler : this.completionHandlers) {
-			handler.run();
-		}
+		this.completionHandlers.forEach(Runnable::run);
 		this.asyncContext = null;
 		this.asyncCompleted.set(true);
 	}
diff --git a/spring-web/src/main/java/org/springframework/web/context/request/async/WebAsyncTask.java b/spring-web/src/main/java/org/springframework/web/context/request/async/WebAsyncTask.java
index 9ef0b89b1e..9e91060a59 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/async/WebAsyncTask.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/async/WebAsyncTask.java
@@ -153,12 +153,14 @@ public class WebAsyncTask<V> implements BeanFactoryAware {
 	}
 
 	/**
-	 * Register code to invoke when an error occurred while processing the async request.
-	 * <p>This method is called from a container thread when an error occurred while processing
-	 * an async request before the {@code Callable} has completed. The callback is executed in
-	 * the same thread and therefore should return without blocking. It may return
-	 * an alternative value to use, including an {@link Exception} or return
+	 * Register code to invoke for an error during async request processing.
+	 * <p>This method is called from a container thread when an error occurred
+	 * while processing an async request before the {@code Callable} has
+	 * completed. The callback is executed in the same thread and therefore
+	 * should return without blocking. It may return an alternative value to
+	 * use, including an {@link Exception} or return
 	 * {@link CallableProcessingInterceptor#RESULT_NONE RESULT_NONE}.
+	 * @since 5.0
 	 */
 	public void onError(Callable<V> callback) {
 		this.errorCallback = callback;
diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ResponseBodyEmitter.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ResponseBodyEmitter.java
index 6a8cc2dbaa..e59a8b07e0 100644
--- a/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ResponseBodyEmitter.java
+++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ResponseBodyEmitter.java
@@ -217,9 +217,10 @@ public class ResponseBodyEmitter {
 	}
 
 	/**
-	 * Register code to invoke when an error occurred while processing the async request.
-	 * This method is called from a container thread when an error occurred while processing
-	 * an async request.
+	 * Register code to invoke for an error during async request processing.
+	 * This method is called from a container thread when an error occurred
+	 * while processing an async request.
+	 * @since 5.0
 	 */
 	public synchronized void onError(Consumer<Throwable> callback) {
 		this.errorCallback.setDelegate(callback);