Polishing

spring-core/src/main/java/org/springframework/core/annotation/AnnotationAttributes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -363,7 +363,7 @@ public class AnnotationAttributes extends LinkedHashMap<String, Object> {
 	private void assertAttributeType(String attributeName, Object attributeValue, Class<?> expectedType) {
 		if (!expectedType.isInstance(attributeValue)) {
 			throw new IllegalArgumentException(String.format(
-					"Attribute '%s' is of type [%s], but [%s] was expected in attributes for annotation [%s]",
+					"Attribute '%s' is of type %s, but %s was expected in attributes for annotation [%s]",
 					attributeName, attributeValue.getClass().getSimpleName(), expectedType.getSimpleName(),
 					this.displayName));
 		}

spring-core/src/main/java/org/springframework/core/type/classreading/AnnotationReadingVisitorUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -28,6 +28,7 @@ import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.ObjectUtils;
 
@@ -124,7 +125,7 @@ abstract class AnnotationReadingVisitorUtils {
 
 		// Get the unmerged list of attributes for the target annotation.
 		List<AnnotationAttributes> attributesList = attributesMap.get(annotationName);
-		if (attributesList == null || attributesList.isEmpty()) {
+		if (CollectionUtils.isEmpty(attributesList)) {
 			return null;
 		}
 

spring-core/src/test/java/org/springframework/core/annotation/AnnotationAttributesTests.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.
@@ -154,7 +154,7 @@ public class AnnotationAttributesTests {
 	public void getEnumWithTypeMismatch() {
 		attributes.put("color", "RED");
 		exception.expect(IllegalArgumentException.class);
-		exception.expectMessage(containsString("Attribute 'color' is of type [String], but [Enum] was expected"));
+		exception.expectMessage(containsString("Attribute 'color' is of type String, but Enum was expected"));
 		attributes.getEnum("color");
 	}