Rename PayloadArgumentResolver to PayloadMethodArgumentResolver

Closes gh-22888

Author: jhoeller

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/DefaultMessageHandlerMethodFactory.java

@@ -100,7 +100,7 @@ public void setMessageConverter(MessageConverter messageConverter) {
 	/**
 	 * Set the Validator instance used for validating {@code @Payload} arguments.
 	 * @see org.springframework.validation.annotation.Validated
-	 * @see org.springframework.messaging.handler.annotation.support.PayloadArgumentResolver
+	 * @see PayloadMethodArgumentResolver
 	 */
 	public void setValidator(Validator validator) {
 		this.validator = validator;
@@ -173,7 +173,7 @@ protected List<HandlerMethodArgumentResolver> initArgumentResolvers() {
 		}
 
 		Assert.notNull(this.messageConverter, "MessageConverter not configured");
-		resolvers.add(new PayloadArgumentResolver(this.messageConverter, this.validator));
+		resolvers.add(new PayloadMethodArgumentResolver(this.messageConverter, this.validator));
 
 		return resolvers;
 	}

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/PayloadArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -16,50 +16,24 @@
 
 package org.springframework.messaging.handler.annotation.support;
 
-import java.lang.annotation.Annotation;
-
-import org.springframework.core.MethodParameter;
-import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.lang.Nullable;
-import org.springframework.messaging.Message;
-import org.springframework.messaging.converter.MessageConversionException;
 import org.springframework.messaging.converter.MessageConverter;
-import org.springframework.messaging.converter.SmartMessageConverter;
-import org.springframework.messaging.handler.annotation.Payload;
-import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
-import org.springframework.util.Assert;
-import org.springframework.util.ClassUtils;
-import org.springframework.util.ObjectUtils;
-import org.springframework.util.StringUtils;
-import org.springframework.validation.BeanPropertyBindingResult;
-import org.springframework.validation.BindingResult;
-import org.springframework.validation.ObjectError;
-import org.springframework.validation.SmartValidator;
 import org.springframework.validation.Validator;
-import org.springframework.validation.annotation.Validated;
 
 /**
  * A resolver to extract and convert the payload of a message using a
  * {@link MessageConverter}. It also validates the payload using a
  * {@link Validator} if the argument is annotated with a Validation annotation.
  *
- * <p>This {@link HandlerMethodArgumentResolver} should be ordered last as it
- * supports all types and does not require the {@link Payload} annotation.
- *
  * @author Rossen Stoyanchev
+ * @author Juergen Hoeller
  * @author Brian Clozel
  * @author Stephane Nicoll
  * @since 4.0
+ * @deprecated as of 5.2, in favor of {@link PayloadMethodArgumentResolver}
  */
-public class PayloadArgumentResolver implements HandlerMethodArgumentResolver {
-
-	private final MessageConverter converter;
-
-	@Nullable
-	private final Validator validator;
-
-	private final boolean useDefaultResolution;
-
+@Deprecated
+public class PayloadArgumentResolver extends PayloadMethodArgumentResolver {
 
 	/**
 	 * Create a new {@code PayloadArgumentResolver} with the given
@@ -93,119 +67,8 @@ public PayloadArgumentResolver(MessageConverter messageConverter, @Nullable Vali
 	public PayloadArgumentResolver(MessageConverter messageConverter, @Nullable Validator validator,
 			boolean useDefaultResolution) {
 
-		Assert.notNull(messageConverter, "MessageConverter must not be null");
-		this.converter = messageConverter;
-		this.validator = validator;
-		this.useDefaultResolution = useDefaultResolution;
-	}
-
-
-	@Override
-	public boolean supportsParameter(MethodParameter parameter) {
-		return (parameter.hasParameterAnnotation(Payload.class) || this.useDefaultResolution);
-	}
-
-	@Override
-	@Nullable
-	public Object resolveArgument(MethodParameter parameter, Message<?> message) throws Exception {
-		Payload ann = parameter.getParameterAnnotation(Payload.class);
-		if (ann != null && StringUtils.hasText(ann.expression())) {
-			throw new IllegalStateException("@Payload SpEL expressions not supported by this resolver");
-		}
 
-		Object payload = message.getPayload();
-		if (isEmptyPayload(payload)) {
-			if (ann == null || ann.required()) {
-				String paramName = getParameterName(parameter);
-				BindingResult bindingResult = new BeanPropertyBindingResult(payload, paramName);
-				bindingResult.addError(new ObjectError(paramName, "Payload value must not be empty"));
-				throw new MethodArgumentNotValidException(message, parameter, bindingResult);
-			}
-			else {
-				return null;
-			}
-		}
-
-		Class<?> targetClass = parameter.getParameterType();
-		Class<?> payloadClass = payload.getClass();
-		if (ClassUtils.isAssignable(targetClass, payloadClass)) {
-			validate(message, parameter, payload);
-			return payload;
-		}
-		else {
-			if (this.converter instanceof SmartMessageConverter) {
-				SmartMessageConverter smartConverter = (SmartMessageConverter) this.converter;
-				payload = smartConverter.fromMessage(message, targetClass, parameter);
-			}
-			else {
-				payload = this.converter.fromMessage(message, targetClass);
-			}
-			if (payload == null) {
-				throw new MessageConversionException(message, "Cannot convert from [" +
-						payloadClass.getName() + "] to [" + targetClass.getName() + "] for " + message);
-			}
-			validate(message, parameter, payload);
-			return payload;
-		}
-	}
-
-	private String getParameterName(MethodParameter param) {
-		String paramName = param.getParameterName();
-		return (paramName != null ? paramName : "Arg " + param.getParameterIndex());
-	}
-
-	/**
-	 * Specify if the given {@code payload} is empty.
-	 * @param payload the payload to check (can be {@code null})
-	 */
-	protected boolean isEmptyPayload(@Nullable Object payload) {
-		if (payload == null) {
-			return true;
-		}
-		else if (payload instanceof byte[]) {
-			return ((byte[]) payload).length == 0;
-		}
-		else if (payload instanceof String) {
-			return !StringUtils.hasText((String) payload);
-		}
-		else {
-			return false;
-		}
-	}
-
-	/**
-	 * Validate the payload if applicable.
-	 * <p>The default implementation checks for {@code @javax.validation.Valid},
-	 * Spring's {@link org.springframework.validation.annotation.Validated},
-	 * and custom annotations whose name starts with "Valid".
-	 * @param message the currently processed message
-	 * @param parameter the method parameter
-	 * @param target the target payload object
-	 * @throws MethodArgumentNotValidException in case of binding errors
-	 */
-	protected void validate(Message<?> message, MethodParameter parameter, Object target) {
-		if (this.validator == null) {
-			return;
-		}
-		for (Annotation ann : parameter.getParameterAnnotations()) {
-			Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
-			if (validatedAnn != null || ann.annotationType().getSimpleName().startsWith("Valid")) {
-				Object hints = (validatedAnn != null ? validatedAnn.value() : AnnotationUtils.getValue(ann));
-				Object[] validationHints = (hints instanceof Object[] ? (Object[]) hints : new Object[] {hints});
-				BeanPropertyBindingResult bindingResult =
-						new BeanPropertyBindingResult(target, getParameterName(parameter));
-				if (!ObjectUtils.isEmpty(validationHints) && this.validator instanceof SmartValidator) {
-					((SmartValidator) this.validator).validate(target, bindingResult, validationHints);
-				}
-				else {
-					this.validator.validate(target, bindingResult);
-				}
-				if (bindingResult.hasErrors()) {
-					throw new MethodArgumentNotValidException(message, parameter, bindingResult);
-				}
-				break;
-			}
-		}
+		super(messageConverter, validator, useDefaultResolution);
 	}
 
 }