Make CodecException handling consistent

This commit makes CodecException handling consistent between functional
and annotation-based APIs. It now returns by default 4xx status code
for decoding error and 5xx for encoding error + print the error reason
in logs without the full stack trace in both variants.

Issue: SPR-15355

spring-web/src/main/java/org/springframework/http/codec/DecoderHttpMessageReader.java

@@ -21,6 +21,9 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.core.codec.CodecException;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.server.ResponseStatusException;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -85,7 +88,9 @@ public class DecoderHttpMessageReader<T> implements HttpMessageReader<T> {
 			Map<String, Object> hints) {
 
 		MediaType contentType = getContentType(message);
-		return this.decoder.decode(message.getBody(), elementType, contentType, hints);
+		return this.decoder
+				.decode(message.getBody(), elementType, contentType, hints)
+				.mapError(this::mapError);
 	}
 
 	@Override
@@ -93,7 +98,9 @@ public class DecoderHttpMessageReader<T> implements HttpMessageReader<T> {
 			Map<String, Object> hints) {
 
 		MediaType contentType = getContentType(message);
-		return this.decoder.decodeToMono(message.getBody(), elementType, contentType, hints);
+		return this.decoder
+				.decodeToMono(message.getBody(), elementType, contentType, hints)
+				.mapError(this::mapError);
 	}
 
 	private MediaType getContentType(HttpMessage inputMessage) {
@@ -101,6 +108,16 @@ public class DecoderHttpMessageReader<T> implements HttpMessageReader<T> {
 		return (contentType != null ? contentType : MediaType.APPLICATION_OCTET_STREAM);
 	}
 
+	private Throwable mapError(Throwable ex) {
+		if (ex instanceof ResponseStatusException) {
+			return ex;
+		}
+		else if (ex instanceof CodecException) {
+			return new ResponseStatusException(HttpStatus.BAD_REQUEST, "Failed to decode HTTP message", ex);
+		}
+		return new ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "Failed to decode HTTP message", ex);
+	}
+
 
 	// Server-side only...
 

spring-web/src/main/java/org/springframework/http/codec/EncoderHttpMessageWriter.java

@@ -22,6 +22,8 @@ import java.util.List;
 import java.util.Map;
 
 import org.reactivestreams.Publisher;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.server.ResponseStatusException;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -95,8 +97,9 @@ public class EncoderHttpMessageWriter<T> implements HttpMessageWriter<T> {
 
 		MediaType contentType = updateContentType(message, mediaType);
 
-		Flux<DataBuffer> body = this.encoder.encode(
+		Flux<DataBuffer> body = this.encoder
-				inputStream, message.bufferFactory(), elementType, contentType, hints);
+				.encode(inputStream, message.bufferFactory(), elementType, contentType, hints)
+				.mapError(this::mapError);
 
 		return isStreamingMediaType(contentType) ?
 				message.writeAndFlushWith(body.map(Flux::just)) :
@@ -135,6 +138,13 @@ public class EncoderHttpMessageWriter<T> implements HttpMessageWriter<T> {
 						.anyMatch(contentType::isCompatibleWith);
 	}
 
+	private Throwable mapError(Throwable ex) {
+		if (ex instanceof ResponseStatusException) {
+			return ex;
+		}
+		return new ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "Failed to encode HTTP message", ex);
+	}
+
 
 	// Server side only...
 

spring-web/src/main/java/org/springframework/web/server/handler/ResponseStatusExceptionHandler.java

@@ -16,6 +16,8 @@
 
 package org.springframework.web.server.handler;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 
 import org.springframework.web.server.ResponseStatusException;
@@ -26,14 +28,20 @@ import org.springframework.web.server.WebExceptionHandler;
  * Handle {@link ResponseStatusException} by setting the response status.
  *
  * @author Rossen Stoyanchev
+ * @author Sebastien Deleuze
  * @since 5.0
  */
 public class ResponseStatusExceptionHandler implements WebExceptionHandler {
 
+	private static final Log logger = LogFactory.getLog(ResponseStatusExceptionHandler.class);
+
 	@Override
 	public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
 		if (ex instanceof ResponseStatusException) {
 			exchange.getResponse().setStatusCode(((ResponseStatusException) ex).getStatus());
+			if (ex.getMessage() != null) {
+				logger.error(ex.getMessage());
+			}
 			return Mono.empty();
 		}
 		return Mono.error(ex);

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RouterFunctions.java

@@ -237,6 +237,9 @@ public abstract class RouterFunctions {
 					.otherwise(ResponseStatusException.class,
 							ex -> {
 								exchange.getResponse().setStatusCode(ex.getStatus());
+								if (ex.getMessage() != null) {
+									logger.error(ex.getMessage());
+								}
 								return Mono.empty();
 							});
 		});

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractMessageReaderArgumentResolver.java

@@ -22,14 +22,11 @@ import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+import org.springframework.core.*;
+import org.springframework.web.server.ResponseStatusException;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-import org.springframework.core.Conventions;
-import org.springframework.core.MethodParameter;
-import org.springframework.core.ReactiveAdapter;
-import org.springframework.core.ReactiveAdapterRegistry;
-import org.springframework.core.ResolvableType;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.http.MediaType;
 import org.springframework.http.codec.HttpMessageReader;
@@ -154,7 +151,7 @@ public abstract class AbstractMessageReaderArgumentResolver extends HandlerMetho
 	}
 
 	private ServerWebInputException getReadError(MethodParameter parameter, Throwable ex) {
-		return new ServerWebInputException("Failed to read HTTP message", parameter, ex);
+		return new ServerWebInputException("Failed to read HTTP message", parameter, ex instanceof ResponseStatusException ? ex.getCause() : ex);
 	}
 
 	private ServerWebInputException getRequiredBodyError(MethodParameter parameter) {

spring-webflux/src/test/java/org/springframework/web/reactive/DispatcherHandlerErrorTests.java

@@ -102,7 +102,7 @@ public class DispatcherHandlerErrorTests {
 		Mono<Void> publisher = this.dispatcherHandler.handle(exchange);
 
 		StepVerifier.create(publisher)
-				.consumeErrorWith(error -> assertSame(EXCEPTION, error))
+				.consumeErrorWith(error -> assertSame(EXCEPTION, error.getCause()))
 				.verify();
 	}