Apply handleMissingValue in case of null conversion result as well

Closes gh-23939

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/reactive/AbstractNamedValueMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -82,7 +82,6 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements SyncHa
 
 	@Override
 	public Object resolveArgumentValue(MethodParameter parameter, Message<?> message) {
-
 		NamedValueInfo namedValueInfo = getNamedValueInfo(parameter);
 		MethodParameter nestedParameter = parameter.nestedIfOptional();
 
@@ -108,6 +107,11 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements SyncHa
 
 		if (parameter != nestedParameter || !ClassUtils.isAssignableValue(parameter.getParameterType(), arg)) {
 			arg = this.conversionService.convert(arg, TypeDescriptor.forObject(arg), new TypeDescriptor(parameter));
+			// Check for null value after conversion of incoming argument value
+			if (arg == null && namedValueInfo.defaultValue == null &&
+					namedValueInfo.required && !nestedParameter.isOptional()) {
+				handleMissingValue(namedValueInfo.name, nestedParameter, message);
+			}
 		}
 
 		return arg;
@@ -144,10 +148,9 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements SyncHa
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				Class<?> type = parameter.getParameterType();
 				throw new IllegalArgumentException(
-						"Name for argument of type [" + type.getName() + "] not specified, " +
-								"and parameter name information not found in class file either.");
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		return new NamedValueInfo(name, info.required,

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -80,8 +80,8 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		// Possibly remove after discussion in gh-23882.
 
 		//noinspection ConstantConditions
-		this.conversionService = conversionService != null ?
-				conversionService : DefaultConversionService.getSharedInstance();
+		this.conversionService = (conversionService != null ?
+				conversionService : DefaultConversionService.getSharedInstance());
 
 		this.configurableBeanFactory = beanFactory;
 		this.expressionContext = (beanFactory != null ? new BeanExpressionContext(beanFactory, null) : null);
@@ -116,6 +116,11 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 
 		if (parameter != nestedParameter || !ClassUtils.isAssignableValue(parameter.getParameterType(), arg)) {
 			arg = this.conversionService.convert(arg, TypeDescriptor.forObject(arg), new TypeDescriptor(parameter));
+			// Check for null value after conversion of incoming argument value
+			if (arg == null && namedValueInfo.defaultValue == null &&
+					namedValueInfo.required && !nestedParameter.isOptional()) {
+				handleMissingValue(namedValueInfo.name, nestedParameter, message);
+			}
 		}
 
 		handleResolvedValue(arg, namedValueInfo.name, parameter, message);
@@ -154,10 +159,9 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				Class<?> type = parameter.getParameterType();
 				throw new IllegalArgumentException(
-						"Name for argument of type [" + type.getName() + "] not specified, " +
-								"and parameter name information not found in class file either.");
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		return new NamedValueInfo(name, info.required,

spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -99,7 +99,7 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		NamedValueInfo namedValueInfo = getNamedValueInfo(parameter);
 		MethodParameter nestedParameter = parameter.nestedIfOptional();
 
-		Object resolvedName = resolveStringValue(namedValueInfo.name);
+		Object resolvedName = resolveEmbeddedValuesAndExpressions(namedValueInfo.name);
 		if (resolvedName == null) {
 			throw new IllegalArgumentException(
 					"Specified name must not resolve to null: [" + namedValueInfo.name + "]");
@@ -108,7 +108,7 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		Object arg = resolveName(resolvedName.toString(), nestedParameter, webRequest);
 		if (arg == null) {
 			if (namedValueInfo.defaultValue != null) {
-				arg = resolveStringValue(namedValueInfo.defaultValue);
+				arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
 			}
 			else if (namedValueInfo.required && !nestedParameter.isOptional()) {
 				handleMissingValue(namedValueInfo.name, nestedParameter, webRequest);
@@ -116,7 +116,7 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			arg = handleNullValue(namedValueInfo.name, arg, nestedParameter.getNestedParameterType());
 		}
 		else if ("".equals(arg) && namedValueInfo.defaultValue != null) {
-			arg = resolveStringValue(namedValueInfo.defaultValue);
+			arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
 		}
 
 		if (binderFactory != null) {
@@ -132,6 +132,11 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 				throw new MethodArgumentTypeMismatchException(arg, ex.getRequiredType(),
 						namedValueInfo.name, parameter, ex.getCause());
 			}
+			// Check for null value after conversion of incoming argument value
+			if (arg == null && namedValueInfo.defaultValue == null &&
+					namedValueInfo.required && !nestedParameter.isOptional()) {
+				handleMissingValue(namedValueInfo.name, nestedParameter, webRequest);
+			}
 		}
 
 		handleResolvedValue(arg, namedValueInfo.name, parameter, mavContainer, webRequest);
@@ -169,8 +174,8 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			name = parameter.getParameterName();
 			if (name == null) {
 				throw new IllegalArgumentException(
-						"Name for argument type [" + parameter.getNestedParameterType().getName() +
-						"] not available, and parameter name information not found in class file either.");
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);
@@ -182,13 +187,13 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 	 * potentially containing placeholders and expressions.
 	 */
 	@Nullable
-	private Object resolveStringValue(String value) {
-		if (this.configurableBeanFactory == null) {
+	private Object resolveEmbeddedValuesAndExpressions(String value) {
+		if (this.configurableBeanFactory == null || this.expressionContext == null) {
 			return value;
 		}
 		String placeholdersResolved = this.configurableBeanFactory.resolveEmbeddedValue(value);
 		BeanExpressionResolver exprResolver = this.configurableBeanFactory.getBeanExpressionResolver();
-		if (exprResolver == null || this.expressionContext == null) {
+		if (exprResolver == null) {
 			return value;
 		}
 		return exprResolver.evaluate(placeholdersResolved, this.expressionContext);

spring-web/src/test/java/org/springframework/web/method/annotation/RequestHeaderMethodArgumentResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -31,6 +31,7 @@ import org.springframework.core.MethodParameter;
 import org.springframework.core.annotation.SynthesizingMethodParameter;
 import org.springframework.format.support.DefaultFormattingConversionService;
 import org.springframework.util.ReflectionUtils;
+import org.springframework.web.bind.MissingRequestHeaderException;
 import org.springframework.web.bind.ServletRequestBindingException;
 import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.support.ConfigurableWebBindingInitializer;
@@ -66,6 +67,7 @@ class RequestHeaderMethodArgumentResolverTests {
 	private MethodParameter paramDate;
 	private MethodParameter paramInstant;
 	private MethodParameter paramUuid;
+	private MethodParameter paramUuidOptional;
 
 	private MockHttpServletRequest servletRequest;
 
@@ -90,6 +92,7 @@ class RequestHeaderMethodArgumentResolverTests {
 		paramDate = new SynthesizingMethodParameter(method, 7);
 		paramInstant = new SynthesizingMethodParameter(method, 8);
 		paramUuid = new SynthesizingMethodParameter(method, 9);
+		paramUuidOptional = new SynthesizingMethodParameter(method, 10);
 
 		servletRequest = new MockHttpServletRequest();
 		webRequest = new ServletWebRequest(servletRequest, new MockHttpServletResponse());
@@ -265,7 +268,28 @@ class RequestHeaderMethodArgumentResolverTests {
 
 		ConfigurableWebBindingInitializer bindingInitializer = new ConfigurableWebBindingInitializer();
 		bindingInitializer.setConversionService(new DefaultFormattingConversionService());
-		Object result = resolver.resolveArgument(paramUuid, null, webRequest,
+
+		assertThatExceptionOfType(MissingRequestHeaderException.class).isThrownBy(() ->
+				resolver.resolveArgument(paramUuid, null, webRequest,
+						new DefaultDataBinderFactory(bindingInitializer)));
+	}
+
+	@Test
+	void uuidConversionWithEmptyValueOptional() throws Exception {
+		uuidConversionWithEmptyOrBlankValueOptional("");
+	}
+
+	@Test
+	void uuidConversionWithBlankValueOptional() throws Exception {
+		uuidConversionWithEmptyOrBlankValueOptional("     ");
+	}
+
+	private void uuidConversionWithEmptyOrBlankValueOptional(String uuid) throws Exception {
+		servletRequest.addHeader("name", uuid);
+
+		ConfigurableWebBindingInitializer bindingInitializer = new ConfigurableWebBindingInitializer();
+		bindingInitializer.setConversionService(new DefaultFormattingConversionService());
+		Object result = resolver.resolveArgument(paramUuidOptional, null, webRequest,
 				new DefaultDataBinderFactory(bindingInitializer));
 
 		assertThat(result).isNull();
@@ -282,7 +306,8 @@ class RequestHeaderMethodArgumentResolverTests {
 			@RequestHeader("name") Map<?, ?> unsupported,
 			@RequestHeader("name") Date dateParam,
 			@RequestHeader("name") Instant instantParam,
-			@RequestHeader("name") UUID uuid) {
+			@RequestHeader("name") UUID uuid,
+			@RequestHeader(name = "name", required = false) UUID uuidOptional) {
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -144,9 +144,9 @@ public abstract class AbstractNamedValueArgumentResolver extends HandlerMethodAr
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				String type = parameter.getNestedParameterType().getName();
-				throw new IllegalArgumentException("Name for argument type [" + type + "] not " +
-						"available, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException(
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);