Document need for -parameters flag in exception messages

Closes gh-31675

Author: sbrannen

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

@@ -152,9 +152,10 @@ private NamedValueInfo updateNamedValueInfo(MethodParameter parameter, NamedValu
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException(
-						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
-						"] not specified, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException("""
+						Name for argument of type [%s] not specified, and parameter name information not \
+						available via reflection. Ensure that the compiler uses the '-parameters' flag."""
+							.formatted(parameter.getNestedParameterType().getName()));
 			}
 		}
 		return new NamedValueInfo(name, info.required,

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

@@ -162,9 +162,10 @@ private NamedValueInfo updateNamedValueInfo(MethodParameter parameter, NamedValu
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException(
-						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
-						"] not specified, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException("""
+						Name for argument of type [%s] not specified, and parameter name information not \
+						available via reflection. Ensure that the compiler uses the '-parameters' flag."""
+							.formatted(parameter.getNestedParameterType().getName()));
 			}
 		}
 		return new NamedValueInfo(name, info.required,

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

@@ -179,9 +179,10 @@ private NamedValueInfo updateNamedValueInfo(MethodParameter parameter, NamedValu
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException(
-						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
-						"] not specified, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException("""
+						Name for argument of type [%s] not specified, and parameter name information not \
+						available via reflection. Ensure that the compiler uses the '-parameters' flag."""
+							.formatted(parameter.getNestedParameterType().getName()));
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);

spring-web/src/main/java/org/springframework/web/service/invoker/AbstractNamedValueArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -127,9 +127,10 @@ private NamedValueInfo updateNamedValueInfo(MethodParameter parameter, NamedValu
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException(
-						"Name for argument of type [" + parameter.getParameterType().getName() + "] " +
-								"not specified, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException("""
+						Name for argument of type [%s] not specified, and parameter name information not \
+						available via reflection. Ensure that the compiler uses the '-parameters' flag."""
+							.formatted(parameter.getNestedParameterType().getName()));
 			}
 		}
 		boolean required = (info.required && !parameter.getParameterType().equals(Optional.class));

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

@@ -152,9 +152,10 @@ private NamedValueInfo updateNamedValueInfo(MethodParameter parameter, NamedValu
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException(
-						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
-						"] not specified, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException("""
+						Name for argument of type [%s] not specified, and parameter name information not \
+						available via reflection. Ensure that the compiler uses the '-parameters' flag."""
+							.formatted(parameter.getNestedParameterType().getName()));
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);