Polishing

Closes gh-33681

Author: ngocnhan-tran1996

spring-core/src/main/java/org/springframework/util/MultiToSingleValueMapAdapter.java

@@ -139,11 +139,11 @@ public Collection<V> values() {
 		Collection<V> values = this.values;
 		if (values == null) {
 			Collection<List<V>> targetValues = this.targetMap.values();
-			values = new AbstractCollection<V>() {
+			values = new AbstractCollection<>() {
 				@Override
 				public Iterator<V> iterator() {
 					Iterator<List<V>> targetIterator = targetValues.iterator();
-					return new Iterator<V>() {
+					return new Iterator<>() {
 						@Override
 						public boolean hasNext() {
 							return targetIterator.hasNext();

spring-test/src/main/java/org/springframework/test/web/servlet/result/PrintingResultHandler.java

@@ -207,7 +207,7 @@ protected void printResolvedException(@Nullable Exception resolvedException) thr
 	protected void printModelAndView(@Nullable ModelAndView mav) throws Exception {
 		this.printer.printValue("View name", (mav != null) ? mav.getViewName() : null);
 		this.printer.printValue("View", (mav != null) ? mav.getView() : null);
-		if (mav == null || mav.getModel().size() == 0) {
+		if (mav == null || mav.getModel().isEmpty()) {
 			this.printer.printValue("Model", null);
 		}
 		else {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -65,7 +65,8 @@ public void handleReturnValue(@Nullable Object returnValue, MethodParameter retu
 		if (returnValue == null) {
 			return;
 		}
-		else if (returnValue instanceof Model model) {
+
+		if (returnValue instanceof Model model) {
 			mavContainer.addAllAttributes(model.asMap());
 		}
 		else {