diff --git a/spring-context/src/test/java/org/springframework/context/annotation/ComponentScanAnnotationIntegrationTests.java b/spring-context/src/test/java/org/springframework/context/annotation/ComponentScanAnnotationIntegrationTests.java
index bd2535dab86..08f45994289 100644
--- a/spring-context/src/test/java/org/springframework/context/annotation/ComponentScanAnnotationIntegrationTests.java
+++ b/spring-context/src/test/java/org/springframework/context/annotation/ComponentScanAnnotationIntegrationTests.java
@@ -21,7 +21,7 @@ import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
-import java.util.HashSet;
+import java.util.Set;
 
 import example.scannable.CustomComponent;
 import example.scannable.CustomStereotype;
@@ -396,9 +396,7 @@ class ComponentScanWithCustomTypeFilter {
 	@SuppressWarnings({ "rawtypes", "serial", "unchecked" })
 	public static CustomAutowireConfigurer customAutowireConfigurer() {
 		CustomAutowireConfigurer cac = new CustomAutowireConfigurer();
-		cac.setCustomQualifierTypes(new HashSet() {{
-				add(ComponentScanParserTests.CustomAnnotation.class);
-		}});
+		cac.setCustomQualifierTypes(Set.of(ComponentScanParserTests.CustomAnnotation.class));
 		return cac;
 	}
 
diff --git a/spring-core/src/test/java/org/springframework/core/env/CustomEnvironmentTests.java b/spring-core/src/test/java/org/springframework/core/env/CustomEnvironmentTests.java
index 258fc362269..b3294c30161 100644
--- a/spring-core/src/test/java/org/springframework/core/env/CustomEnvironmentTests.java
+++ b/spring-core/src/test/java/org/springframework/core/env/CustomEnvironmentTests.java
@@ -16,8 +16,6 @@
 
 package org.springframework.core.env;
 
-import java.util.Collections;
-import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
@@ -51,7 +49,7 @@ class CustomEnvironmentTests {
 		class CustomEnvironment extends AbstractEnvironment {
 			@Override
 			protected Set<String> getReservedDefaultProfiles() {
-				return Collections.emptySet();
+				return Set.of();
 			}
 		}
 
@@ -64,7 +62,7 @@ class CustomEnvironmentTests {
 		class CustomEnvironment extends AbstractEnvironment {
 			@Override
 			protected Set<String> getReservedDefaultProfiles() {
-				return Collections.singleton("rd1");
+				return Set.of("rd1");
 			}
 		}
 
@@ -79,10 +77,7 @@ class CustomEnvironmentTests {
 			@Override
 			@SuppressWarnings("serial")
 			protected Set<String> getReservedDefaultProfiles() {
-				return new HashSet<>() {{
-						add("rd1");
-						add("rd2");
-				}};
+				return Set.of("rd1", "rd2");
 			}
 		}
 
@@ -151,7 +146,7 @@ class CustomEnvironmentTests {
 			@Override
 			@Nullable
 			public String getProperty(String key) {
-				return super.getProperty(key)+"-test";
+				return super.getProperty(key) + "-test";
 			}
 		}
 
diff --git a/spring-core/src/test/java/org/springframework/core/env/PropertySourceTests.java b/spring-core/src/test/java/org/springframework/core/env/PropertySourceTests.java
index beeaf18e8ea..e8131bc1276 100644
--- a/spring-core/src/test/java/org/springframework/core/env/PropertySourceTests.java
+++ b/spring-core/src/test/java/org/springframework/core/env/PropertySourceTests.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.
@@ -17,7 +17,6 @@
 package org.springframework.core.env;
 
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
@@ -37,12 +36,8 @@ class PropertySourceTests {
 	@Test
 	@SuppressWarnings("serial")
 	void equals() {
-		Map<String, Object> map1 = new HashMap<>() {{
-			put("a", "b");
-		}};
-		Map<String, Object> map2 = new HashMap<>() {{
-			put("c", "d");
-		}};
+		Map<String, Object> map1 = Map.of("a", "b");
+		Map<String, Object> map2 = Map.of("c", "d");
 		Properties props1 = new Properties() {{
 			setProperty("a", "b");
 		}};
@@ -69,12 +64,8 @@ class PropertySourceTests {
 	@Test
 	@SuppressWarnings("serial")
 	void collectionsOperations() {
-		Map<String, Object> map1 = new HashMap<>() {{
-			put("a", "b");
-		}};
-		Map<String, Object> map2 = new HashMap<>() {{
-			put("c", "d");
-		}};
+		Map<String, Object> map1 = Map.of("a", "b");
+		Map<String, Object> map2 = Map.of("c", "d");
 
 		PropertySource<?> ps1 = new MapPropertySource("ps1", map1);
 		ps1.getSource();
diff --git a/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java b/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java
index 8ba58a63e54..c155247a92f 100644
--- a/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java
+++ b/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.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.
diff --git a/spring-test/src/test/java/org/springframework/test/context/support/DynamicValuesPropertySourceTests.java b/spring-test/src/test/java/org/springframework/test/context/support/DynamicValuesPropertySourceTests.java
index 632eaf8f084..e831c1f19e3 100644
--- a/spring-test/src/test/java/org/springframework/test/context/support/DynamicValuesPropertySourceTests.java
+++ b/spring-test/src/test/java/org/springframework/test/context/support/DynamicValuesPropertySourceTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 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.
@@ -16,8 +16,7 @@
 
 package org.springframework.test.context.support;
 
-import java.util.HashMap;
-import java.util.function.Supplier;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 
@@ -33,10 +32,7 @@ class DynamicValuesPropertySourceTests {
 
 	@SuppressWarnings("serial")
 	private final DynamicValuesPropertySource source = new DynamicValuesPropertySource("test",
-		new HashMap<String, Supplier<Object>>() {{
-			put("a", () -> "A");
-			put("b", () -> "B");
-		}});
+			Map.of("a", () -> "A", "b", () -> "B"));
 
 
 	@Test
@@ -63,7 +59,7 @@ class DynamicValuesPropertySourceTests {
 
 	@Test
 	void getPropertyNamesReturnsNames() {
-		assertThat(this.source.getPropertyNames()).containsExactly("a", "b");
+		assertThat(this.source.getPropertyNames()).containsExactlyInAnyOrder("a", "b");
 	}
 
 }
diff --git a/spring-webmvc/src/test/java/org/springframework/web/servlet/view/InternalResourceViewTests.java b/spring-webmvc/src/test/java/org/springframework/web/servlet/view/InternalResourceViewTests.java
index 9467750ef8a..72f04a1eb9f 100644
--- a/spring-webmvc/src/test/java/org/springframework/web/servlet/view/InternalResourceViewTests.java
+++ b/spring-webmvc/src/test/java/org/springframework/web/servlet/view/InternalResourceViewTests.java
@@ -16,8 +16,6 @@
 
 package org.springframework.web.servlet.view;
 
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 
 import jakarta.servlet.http.HttpServletRequest;
@@ -46,10 +44,7 @@ import static org.mockito.Mockito.verify;
 public class InternalResourceViewTests {
 
 	@SuppressWarnings("serial")
-	private static final Map<String, Object> model = Collections.unmodifiableMap(new HashMap<String, Object>() {{
-		put("foo", "bar");
-		put("I", 1L);
-	}});
+	private static final Map<String, Object> model = Map.of("foo", "bar", "I", 1L);
 
 	private static final String url = "forward-to";