Java Code Examples for org.springframework.core.ReactiveAdapter#isMultiValue()

private Mono<Object> decodeContent(MethodParameter parameter, Message<?> message,
		boolean isContentRequired, Flux<DataBuffer> content, MimeType mimeType) {

	ResolvableType targetType = ResolvableType.forMethodParameter(parameter);
	Class<?> resolvedType = targetType.resolve();
	ReactiveAdapter adapter = (resolvedType != null ? getAdapterRegistry().getAdapter(resolvedType) : null);
	ResolvableType elementType = (adapter != null ? targetType.getGeneric() : targetType);
	isContentRequired = isContentRequired || (adapter != null && !adapter.supportsEmpty());
	Consumer<Object> validator = getValidator(message, parameter);

	Map<String, Object> hints = Collections.emptyMap();

	for (Decoder<?> decoder : this.decoders) {
		if (decoder.canDecode(elementType, mimeType)) {
			if (adapter != null && adapter.isMultiValue()) {
				Flux<?> flux = content
						.map(buffer -> decoder.decode(buffer, elementType, mimeType, hints))
						.onErrorResume(ex -> Flux.error(handleReadError(parameter, message, ex)));
				if (isContentRequired) {
					flux = flux.switchIfEmpty(Flux.error(() -> handleMissingBody(parameter, message)));
				}
				if (validator != null) {
					flux = flux.doOnNext(validator);
				}
				return Mono.just(adapter.fromPublisher(flux));
			}
			else {
				// Single-value (with or without reactive type wrapper)
				Mono<?> mono = content.next()
						.map(buffer -> decoder.decode(buffer, elementType, mimeType, hints))
						.onErrorResume(ex -> Mono.error(handleReadError(parameter, message, ex)));
				if (isContentRequired) {
					mono = mono.switchIfEmpty(Mono.error(() -> handleMissingBody(parameter, message)));
				}
				if (validator != null) {
					mono = mono.doOnNext(validator);
				}
				return (adapter != null ? Mono.just(adapter.fromPublisher(mono)) : Mono.from(mono));
			}
		}
	}

	return Mono.error(new MethodArgumentResolutionException(
			message, parameter, "Cannot decode to [" + targetType + "]" + message));
}
 

@Override
public boolean isAsyncReturnValue(Object returnValue, MethodParameter returnType) {
	ReactiveAdapter adapter = this.adapterRegistry.getAdapter(returnType.getParameterType(), returnValue);
	return (adapter != null && !adapter.isMultiValue() && !adapter.isNoValue());
}
 

/**
 * By default, resolve async attributes supported by the
 * {@link ReactiveAdapterRegistry} to their blocking counterparts.
 * <p>View implementations capable of taking advantage of reactive types
 * can override this method if needed.
 * @return {@code Mono} for the completion of async attributes resolution
 */
protected Mono<Void> resolveAsyncAttributes(Map<String, Object> model) {
	List<String> names = new ArrayList<>();
	List<Mono<?>> valueMonos = new ArrayList<>();

	for (Map.Entry<String, ?> entry : model.entrySet()) {
		Object value =  entry.getValue();
		if (value == null) {
			continue;
		}
		ReactiveAdapter adapter = this.adapterRegistry.getAdapter(null, value);
		if (adapter != null) {
			names.add(entry.getKey());
			if (adapter.isMultiValue()) {
				Flux<Object> fluxValue = Flux.from(adapter.toPublisher(value));
				valueMonos.add(fluxValue.collectList().defaultIfEmpty(Collections.emptyList()));
			}
			else {
				Mono<Object> monoValue = Mono.from(adapter.toPublisher(value));
				valueMonos.add(monoValue.defaultIfEmpty(NO_VALUE));
			}
		}
	}

	if (names.isEmpty()) {
		return Mono.empty();
	}

	return Mono.zip(valueMonos,
			values -> {
				for (int i=0; i < values.length; i++) {
					if (values[i] != NO_VALUE) {
						model.put(names.get(i), values[i]);
					}
					else {
						model.remove(names.get(i));
					}
				}
				return NO_VALUE;
			})
			.then();
}
 

@Override
@SuppressWarnings("unchecked")
public Mono<Void> handleResult(ServerWebExchange exchange, HandlerResult result) {
	Mono<Object> valueMono;
	ResolvableType valueType;
	ReactiveAdapter adapter = getAdapter(result);

	if (adapter != null) {
		if (adapter.isMultiValue()) {
			throw new IllegalArgumentException(
					"Multi-value reactive types not supported in view resolution: " + result.getReturnType());
		}

		valueMono = (result.getReturnValue() != null ?
				Mono.from(adapter.toPublisher(result.getReturnValue())) : Mono.empty());

		valueType = (adapter.isNoValue() ? ResolvableType.forClass(Void.class) :
				result.getReturnType().getGeneric());
	}
	else {
		valueMono = Mono.justOrEmpty(result.getReturnValue());
		valueType = result.getReturnType();
	}

	return valueMono
			.switchIfEmpty(exchange.isNotModified() ? Mono.empty() : NO_VALUE_MONO)
			.flatMap(returnValue -> {

				Mono<List<View>> viewsMono;
				Model model = result.getModel();
				MethodParameter parameter = result.getReturnTypeSource();
				Locale locale = LocaleContextHolder.getLocale(exchange.getLocaleContext());

				Class<?> clazz = valueType.toClass();
				if (clazz == Object.class) {
					clazz = returnValue.getClass();
				}

				if (returnValue == NO_VALUE || clazz == void.class || clazz == Void.class) {
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}
				else if (CharSequence.class.isAssignableFrom(clazz) && !hasModelAnnotation(parameter)) {
					viewsMono = resolveViews(returnValue.toString(), locale);
				}
				else if (Rendering.class.isAssignableFrom(clazz)) {
					Rendering render = (Rendering) returnValue;
					HttpStatus status = render.status();
					if (status != null) {
						exchange.getResponse().setStatusCode(status);
					}
					exchange.getResponse().getHeaders().putAll(render.headers());
					model.addAllAttributes(render.modelAttributes());
					Object view = render.view();
					if (view == null) {
						view = getDefaultViewName(exchange);
					}
					viewsMono = (view instanceof String ? resolveViews((String) view, locale) :
							Mono.just(Collections.singletonList((View) view)));
				}
				else if (Model.class.isAssignableFrom(clazz)) {
					model.addAllAttributes(((Model) returnValue).asMap());
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}
				else if (Map.class.isAssignableFrom(clazz) && !hasModelAnnotation(parameter)) {
					model.addAllAttributes((Map<String, ?>) returnValue);
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}
				else if (View.class.isAssignableFrom(clazz)) {
					viewsMono = Mono.just(Collections.singletonList((View) returnValue));
				}
				else {
					String name = getNameForReturnValue(parameter);
					model.addAttribute(name, returnValue);
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}

				updateBindingContext(result.getBindingContext(), exchange);

				return viewsMono.flatMap(views -> render(views, model.asMap(), exchange));
			});
}
 

/**
 * Read the body from a method argument with {@link HttpMessageReader}.
 * @param bodyParam represents the element type for the body
 * @param actualParam the actual method argument type; possibly different
 * from {@code bodyParam}, e.g. for an {@code HttpEntity} argument
 * @param isBodyRequired true if the body is required
 * @param bindingContext the binding context to use
 * @param exchange the current exchange
 * @return a Mono with the value to use for the method argument
 * @since 5.0.2
 */
protected Mono<Object> readBody(MethodParameter bodyParam, @Nullable MethodParameter actualParam,
		boolean isBodyRequired, BindingContext bindingContext, ServerWebExchange exchange) {

	ResolvableType bodyType = ResolvableType.forMethodParameter(bodyParam);
	ResolvableType actualType = (actualParam != null ? ResolvableType.forMethodParameter(actualParam) : bodyType);
	Class<?> resolvedType = bodyType.resolve();
	ReactiveAdapter adapter = (resolvedType != null ? getAdapterRegistry().getAdapter(resolvedType) : null);
	ResolvableType elementType = (adapter != null ? bodyType.getGeneric() : bodyType);
	isBodyRequired = isBodyRequired || (adapter != null && !adapter.supportsEmpty());

	ServerHttpRequest request = exchange.getRequest();
	ServerHttpResponse response = exchange.getResponse();

	MediaType contentType = request.getHeaders().getContentType();
	MediaType mediaType = (contentType != null ? contentType : MediaType.APPLICATION_OCTET_STREAM);
	Object[] hints = extractValidationHints(bodyParam);

	if (mediaType.isCompatibleWith(MediaType.APPLICATION_FORM_URLENCODED)) {
		return Mono.error(new IllegalStateException(
				"In a WebFlux application, form data is accessed via ServerWebExchange.getFormData()."));
	}

	if (logger.isDebugEnabled()) {
		logger.debug(exchange.getLogPrefix() + (contentType != null ?
				"Content-Type:" + contentType :
				"No Content-Type, using " + MediaType.APPLICATION_OCTET_STREAM));
	}

	for (HttpMessageReader<?> reader : getMessageReaders()) {
		if (reader.canRead(elementType, mediaType)) {
			Map<String, Object> readHints = Hints.from(Hints.LOG_PREFIX_HINT, exchange.getLogPrefix());
			if (adapter != null && adapter.isMultiValue()) {
				if (logger.isDebugEnabled()) {
					logger.debug(exchange.getLogPrefix() + "0..N [" + elementType + "]");
				}
				Flux<?> flux = reader.read(actualType, elementType, request, response, readHints);
				flux = flux.onErrorResume(ex -> Flux.error(handleReadError(bodyParam, ex)));
				if (isBodyRequired) {
					flux = flux.switchIfEmpty(Flux.error(() -> handleMissingBody(bodyParam)));
				}
				if (hints != null) {
					flux = flux.doOnNext(target ->
							validate(target, hints, bodyParam, bindingContext, exchange));
				}
				return Mono.just(adapter.fromPublisher(flux));
			}
			else {
				// Single-value (with or without reactive type wrapper)
				if (logger.isDebugEnabled()) {
					logger.debug(exchange.getLogPrefix() + "0..1 [" + elementType + "]");
				}
				Mono<?> mono = reader.readMono(actualType, elementType, request, response, readHints);
				mono = mono.onErrorResume(ex -> Mono.error(handleReadError(bodyParam, ex)));
				if (isBodyRequired) {
					mono = mono.switchIfEmpty(Mono.error(() -> handleMissingBody(bodyParam)));
				}
				if (hints != null) {
					mono = mono.doOnNext(target ->
							validate(target, hints, bodyParam, bindingContext, exchange));
				}
				return (adapter != null ? Mono.just(adapter.fromPublisher(mono)) : Mono.from(mono));
			}
		}
	}

	// No compatible reader but body may be empty..

	HttpMethod method = request.getMethod();
	if (contentType == null && method != null && SUPPORTED_METHODS.contains(method)) {
		Flux<DataBuffer> body = request.getBody().doOnNext(buffer -> {
			DataBufferUtils.release(buffer);
			// Body not empty, back to 415..
			throw new UnsupportedMediaTypeStatusException(mediaType, this.supportedMediaTypes, elementType);
		});
		if (isBodyRequired) {
			body = body.switchIfEmpty(Mono.error(() -> handleMissingBody(bodyParam)));
		}
		return (adapter != null ? Mono.just(adapter.fromPublisher(body)) : Mono.from(body));
	}

	return Mono.error(new UnsupportedMediaTypeStatusException(mediaType, this.supportedMediaTypes, elementType));
}
 

DeferredResultSubscriber(DeferredResult<Object> result, ReactiveAdapter adapter, ResolvableType elementType) {
	this.result = result;
	this.multiValueSource = adapter.isMultiValue();
	this.values = new CollectedValuesList(elementType);
}
 

@Override
public boolean isAsyncReturnValue(Object returnValue, MethodParameter returnType) {
	ReactiveAdapter adapter = this.adapterRegistry.getAdapter(returnType.getParameterType(), returnValue);
	return (adapter != null && !adapter.isMultiValue() && !adapter.isNoValue());
}
 

/**
 * By default, resolve async attributes supported by the
 * {@link ReactiveAdapterRegistry} to their blocking counterparts.
 * <p>View implementations capable of taking advantage of reactive types
 * can override this method if needed.
 * @return {@code Mono} for the completion of async attributes resolution
 */
protected Mono<Void> resolveAsyncAttributes(Map<String, Object> model) {
	List<String> names = new ArrayList<>();
	List<Mono<?>> valueMonos = new ArrayList<>();

	for (Map.Entry<String, ?> entry : model.entrySet()) {
		Object value =  entry.getValue();
		if (value == null) {
			continue;
		}
		ReactiveAdapter adapter = this.reactiveAdapterRegistry.getAdapter(null, value);
		if (adapter != null) {
			names.add(entry.getKey());
			if (adapter.isMultiValue()) {
				Flux<Object> fluxValue = Flux.from(adapter.toPublisher(value));
				valueMonos.add(fluxValue.collectList().defaultIfEmpty(Collections.emptyList()));
			}
			else {
				Mono<Object> monoValue = Mono.from(adapter.toPublisher(value));
				valueMonos.add(monoValue.defaultIfEmpty(NO_VALUE));
			}
		}
	}

	if (names.isEmpty()) {
		return Mono.empty();
	}

	return Mono.zip(valueMonos,
			values -> {
				for (int i=0; i < values.length; i++) {
					if (values[i] != NO_VALUE) {
						model.put(names.get(i), values[i]);
					}
					else {
						model.remove(names.get(i));
					}
				}
				return NO_VALUE;
			})
			.then();
}
 

@Override
@SuppressWarnings("unchecked")
public Mono<Void> handleResult(ServerWebExchange exchange, HandlerResult result) {
	Mono<Object> valueMono;
	ResolvableType valueType;
	ReactiveAdapter adapter = getAdapter(result);

	if (adapter != null) {
		if (adapter.isMultiValue()) {
			throw new IllegalArgumentException(
					"Multi-value reactive types not supported in view resolution: " + result.getReturnType());
		}

		valueMono = (result.getReturnValue() != null ?
				Mono.from(adapter.toPublisher(result.getReturnValue())) : Mono.empty());

		valueType = (adapter.isNoValue() ? ResolvableType.forClass(Void.class) :
				result.getReturnType().getGeneric());
	}
	else {
		valueMono = Mono.justOrEmpty(result.getReturnValue());
		valueType = result.getReturnType();
	}

	return valueMono
			.switchIfEmpty(exchange.isNotModified() ? Mono.empty() : NO_VALUE_MONO)
			.flatMap(returnValue -> {

				Mono<List<View>> viewsMono;
				Model model = result.getModel();
				MethodParameter parameter = result.getReturnTypeSource();
				Locale locale = LocaleContextHolder.getLocale(exchange.getLocaleContext());

				Class<?> clazz = valueType.toClass();
				if (clazz == Object.class) {
					clazz = returnValue.getClass();
				}

				if (returnValue == NO_VALUE || clazz == void.class || clazz == Void.class) {
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}
				else if (CharSequence.class.isAssignableFrom(clazz) && !hasModelAnnotation(parameter)) {
					viewsMono = resolveViews(returnValue.toString(), locale);
				}
				else if (Rendering.class.isAssignableFrom(clazz)) {
					Rendering render = (Rendering) returnValue;
					HttpStatus status = render.status();
					if (status != null) {
						exchange.getResponse().setStatusCode(status);
					}
					exchange.getResponse().getHeaders().putAll(render.headers());
					model.addAllAttributes(render.modelAttributes());
					Object view = render.view();
					if (view == null) {
						view = getDefaultViewName(exchange);
					}
					viewsMono = (view instanceof String ? resolveViews((String) view, locale) :
							Mono.just(Collections.singletonList((View) view)));
				}
				else if (Model.class.isAssignableFrom(clazz)) {
					model.addAllAttributes(((Model) returnValue).asMap());
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}
				else if (Map.class.isAssignableFrom(clazz) && !hasModelAnnotation(parameter)) {
					model.addAllAttributes((Map<String, ?>) returnValue);
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}
				else if (View.class.isAssignableFrom(clazz)) {
					viewsMono = Mono.just(Collections.singletonList((View) returnValue));
				}
				else {
					String name = getNameForReturnValue(parameter);
					model.addAttribute(name, returnValue);
					viewsMono = resolveViews(getDefaultViewName(exchange), locale);
				}

				updateBindingContext(result.getBindingContext(), exchange);

				return viewsMono.flatMap(views -> render(views, model.asMap(), exchange));
			});
}
 

/**
 * Read the body from a method argument with {@link HttpMessageReader}.
 * @param bodyParam represents the element type for the body
 * @param actualParam the actual method argument type; possibly different
 * from {@code bodyParam}, e.g. for an {@code HttpEntity} argument
 * @param isBodyRequired true if the body is required
 * @param bindingContext the binding context to use
 * @param exchange the current exchange
 * @return a Mono with the value to use for the method argument
 * @since 5.0.2
 */
protected Mono<Object> readBody(MethodParameter bodyParam, @Nullable MethodParameter actualParam,
		boolean isBodyRequired, BindingContext bindingContext, ServerWebExchange exchange) {

	ResolvableType bodyType = ResolvableType.forMethodParameter(bodyParam);
	ResolvableType actualType = (actualParam != null ? ResolvableType.forMethodParameter(actualParam) : bodyType);
	Class<?> resolvedType = bodyType.resolve();
	ReactiveAdapter adapter = (resolvedType != null ? getAdapterRegistry().getAdapter(resolvedType) : null);
	ResolvableType elementType = (adapter != null ? bodyType.getGeneric() : bodyType);
	isBodyRequired = isBodyRequired || (adapter != null && !adapter.supportsEmpty());

	ServerHttpRequest request = exchange.getRequest();
	ServerHttpResponse response = exchange.getResponse();

	MediaType contentType = request.getHeaders().getContentType();
	MediaType mediaType = (contentType != null ? contentType : MediaType.APPLICATION_OCTET_STREAM);
	Object[] hints = extractValidationHints(bodyParam);

	if (logger.isDebugEnabled()) {
		logger.debug(exchange.getLogPrefix() + (contentType != null ?
				"Content-Type:" + contentType :
				"No Content-Type, using " + MediaType.APPLICATION_OCTET_STREAM));
	}

	for (HttpMessageReader<?> reader : getMessageReaders()) {
		if (reader.canRead(elementType, mediaType)) {
			Map<String, Object> readHints = Hints.from(Hints.LOG_PREFIX_HINT, exchange.getLogPrefix());
			if (adapter != null && adapter.isMultiValue()) {
				if (logger.isDebugEnabled()) {
					logger.debug(exchange.getLogPrefix() + "0..N [" + elementType + "]");
				}
				Flux<?> flux = reader.read(actualType, elementType, request, response, readHints);
				flux = flux.onErrorResume(ex -> Flux.error(handleReadError(bodyParam, ex)));
				if (isBodyRequired) {
					flux = flux.switchIfEmpty(Flux.error(() -> handleMissingBody(bodyParam)));
				}
				if (hints != null) {
					flux = flux.doOnNext(target ->
							validate(target, hints, bodyParam, bindingContext, exchange));
				}
				return Mono.just(adapter.fromPublisher(flux));
			}
			else {
				// Single-value (with or without reactive type wrapper)
				if (logger.isDebugEnabled()) {
					logger.debug(exchange.getLogPrefix() + "0..1 [" + elementType + "]");
				}
				Mono<?> mono = reader.readMono(actualType, elementType, request, response, readHints);
				mono = mono.onErrorResume(ex -> Mono.error(handleReadError(bodyParam, ex)));
				if (isBodyRequired) {
					mono = mono.switchIfEmpty(Mono.error(() -> handleMissingBody(bodyParam)));
				}
				if (hints != null) {
					mono = mono.doOnNext(target ->
							validate(target, hints, bodyParam, bindingContext, exchange));
				}
				return (adapter != null ? Mono.just(adapter.fromPublisher(mono)) : Mono.from(mono));
			}
		}
	}

	// No compatible reader but body may be empty..

	HttpMethod method = request.getMethod();
	if (contentType == null && method != null && SUPPORTED_METHODS.contains(method)) {
		Flux<DataBuffer> body = request.getBody().doOnNext(o -> {
			// Body not empty, back to 415..
			throw new UnsupportedMediaTypeStatusException(mediaType, this.supportedMediaTypes, elementType);
		});
		if (isBodyRequired) {
			body = body.switchIfEmpty(Mono.error(() -> handleMissingBody(bodyParam)));
		}
		return (adapter != null ? Mono.just(adapter.fromPublisher(body)) : Mono.from(body));
	}

	return Mono.error(new UnsupportedMediaTypeStatusException(mediaType, this.supportedMediaTypes, elementType));
}
 

DeferredResultSubscriber(DeferredResult<Object> result, ReactiveAdapter adapter, ResolvableType elementType) {
	this.result = result;
	this.multiValueSource = adapter.isMultiValue();
	this.values = new CollectedValuesList(elementType);
}
 

private Publisher<?> body(Object handler, ServerWebExchange exchange) {
	ResolvableType elementType = ResolvableType
			.forClass(this.inspector.getInputType(handler));

	// we effectively delegate type conversion to FunctionCatalog
	elementType = ResolvableType.forClass(String.class);

	ResolvableType actualType = elementType;

	Class<?> resolvedType = elementType.resolve();
	ReactiveAdapter adapter = (resolvedType != null
			? getAdapterRegistry().getAdapter(resolvedType) : null);

	ServerHttpRequest request = exchange.getRequest();
	ServerHttpResponse response = exchange.getResponse();

	MediaType contentType = request.getHeaders().getContentType();
	MediaType mediaType = (contentType != null ? contentType
			: MediaType.APPLICATION_OCTET_STREAM);

	if (logger.isDebugEnabled()) {
		logger.debug(exchange.getLogPrefix() + (contentType != null
				? "Content-Type:" + contentType
				: "No Content-Type, using " + MediaType.APPLICATION_OCTET_STREAM));
	}
	boolean isBodyRequired = (adapter != null && !adapter.supportsEmpty());

	MethodParameter bodyParam = new MethodParameter(handlerMethod(handler), 0);
	for (HttpMessageReader<?> reader : getMessageReaders()) {
		if (reader.canRead(elementType, mediaType)) {
			Map<String, Object> readHints = Hints.from(Hints.LOG_PREFIX_HINT,
					exchange.getLogPrefix());
			if (adapter != null && adapter.isMultiValue()) {
				if (logger.isDebugEnabled()) {
					logger.debug(
							exchange.getLogPrefix() + "0..N [" + elementType + "]");
				}
				Flux<?> flux = reader.read(actualType, elementType, request, response,
						readHints);
				flux = flux.onErrorResume(
						ex -> Flux.error(handleReadError(bodyParam, ex)));
				if (isBodyRequired) {
					flux = flux.switchIfEmpty(
							Flux.error(() -> handleMissingBody(bodyParam)));
				}
				return Mono.just(adapter.fromPublisher(flux));
			}
			else {
				// Single-value (with or without reactive type wrapper)
				if (logger.isDebugEnabled()) {
					logger.debug(exchange.getLogPrefix() + "0..1 [" + elementType + "]");
				}
				Mono<?> mono = reader.readMono(actualType, elementType, request,
						response, readHints).doOnNext(v -> {
							if (logger.isDebugEnabled()) {
								logger.debug("received: " + v);
							}
						});
				mono = mono.onErrorResume(
						ex -> Mono.error(handleReadError(bodyParam, ex)));
				if (isBodyRequired) {
					mono = mono.switchIfEmpty(
							Mono.error(() -> handleMissingBody(bodyParam)));
				}
				return (adapter != null ? Mono.just(adapter.fromPublisher(mono))
						: Mono.from(mono));
			}
		}
	}

	return Mono.error(new UnsupportedMediaTypeStatusException(mediaType,
			Arrays.asList(MediaType.APPLICATION_JSON), elementType));
}