diff --git a/spring-context-support/src/test/java/org/springframework/cache/caffeine/CaffeineCacheManagerTests.java b/spring-context-support/src/test/java/org/springframework/cache/caffeine/CaffeineCacheManagerTests.java
index a9f9858087..261ab391b1 100644
--- a/spring-context-support/src/test/java/org/springframework/cache/caffeine/CaffeineCacheManagerTests.java
+++ b/spring-context-support/src/test/java/org/springframework/cache/caffeine/CaffeineCacheManagerTests.java
@@ -36,10 +36,11 @@ import static org.mockito.Mockito.mock;
  * @author Juergen Hoeller
  * @author Stephane Nicoll
  */
-public class CaffeineCacheManagerTests {
+class CaffeineCacheManagerTests {
 
 	@Test
-	public void testDynamicMode() {
+	@SuppressWarnings("cast")
+	void dynamicMode() {
 		CacheManager cm = new CaffeineCacheManager();
 
 		Cache cache1 = cm.getCache("c1");
@@ -77,7 +78,8 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void testStaticMode() {
+	@SuppressWarnings("cast")
+	void staticMode() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1", "c2");
 
 		Cache cache1 = cm.getCache("c1");
@@ -136,7 +138,8 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void testAsyncMode() {
+	@SuppressWarnings("cast")
+	void asyncMode() {
 		CaffeineCacheManager cm = new CaffeineCacheManager();
 		cm.setAsyncCacheMode(true);
 
@@ -182,7 +185,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void changeCaffeineRecreateCache() {
+	void changeCaffeineRecreateCache() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		Cache cache1 = cm.getCache("c1");
 
@@ -197,7 +200,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void changeCaffeineSpecRecreateCache() {
+	void changeCaffeineSpecRecreateCache() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		Cache cache1 = cm.getCache("c1");
 
@@ -207,7 +210,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void changeCacheSpecificationRecreateCache() {
+	void changeCacheSpecificationRecreateCache() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		Cache cache1 = cm.getCache("c1");
 
@@ -217,7 +220,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void changeCacheLoaderRecreateCache() {
+	void changeCacheLoaderRecreateCache() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		Cache cache1 = cm.getCache("c1");
 
@@ -234,7 +237,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void setCacheNameNullRestoreDynamicMode() {
+	void setCacheNameNullRestoreDynamicMode() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		assertThat(cm.getCache("someCache")).isNull();
 		cm.setCacheNames(null);
@@ -242,7 +245,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void cacheLoaderUseLoadingCache() {
+	void cacheLoaderUseLoadingCache() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		cm.setCacheLoader(key -> {
 			if ("ping".equals(key)) {
@@ -260,7 +263,7 @@ public class CaffeineCacheManagerTests {
 	}
 
 	@Test
-	public void customCacheRegistration() {
+	void customCacheRegistration() {
 		CaffeineCacheManager cm = new CaffeineCacheManager("c1");
 		com.github.benmanes.caffeine.cache.Cache<Object, Object> nc = Caffeine.newBuilder().build();
 		cm.registerCustomCache("c2", nc);
diff --git a/spring-core/src/test/java/org/springframework/core/task/SimpleAsyncTaskExecutorTests.java b/spring-core/src/test/java/org/springframework/core/task/SimpleAsyncTaskExecutorTests.java
index fbdf751435..81bd8b6996 100644
--- a/spring-core/src/test/java/org/springframework/core/task/SimpleAsyncTaskExecutorTests.java
+++ b/spring-core/src/test/java/org/springframework/core/task/SimpleAsyncTaskExecutorTests.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.
@@ -33,17 +33,18 @@ class SimpleAsyncTaskExecutorTests {
 
 	@Test
 	void cannotExecuteWhenConcurrencyIsSwitchedOff() {
-		SimpleAsyncTaskExecutor executor = new SimpleAsyncTaskExecutor();
-		executor.setConcurrencyLimit(ConcurrencyThrottleSupport.NO_CONCURRENCY);
-		assertThat(executor.isThrottleActive()).isTrue();
-		assertThatIllegalStateException().isThrownBy(() ->
-				executor.execute(new NoOpRunnable()));
+		try (SimpleAsyncTaskExecutor executor = new SimpleAsyncTaskExecutor()) {
+			executor.setConcurrencyLimit(ConcurrencyThrottleSupport.NO_CONCURRENCY);
+			assertThat(executor.isThrottleActive()).isTrue();
+			assertThatIllegalStateException().isThrownBy(() -> executor.execute(new NoOpRunnable()));
+		}
 	}
 
 	@Test
 	void throttleIsNotActiveByDefault() {
-		SimpleAsyncTaskExecutor executor = new SimpleAsyncTaskExecutor();
-		assertThat(executor.isThrottleActive()).as("Concurrency throttle must not default to being active (on)").isFalse();
+		try (SimpleAsyncTaskExecutor executor = new SimpleAsyncTaskExecutor()) {
+			assertThat(executor.isThrottleActive()).as("Concurrency throttle must not default to being active (on)").isFalse();
+		}
 	}
 
 	@Test
@@ -67,8 +68,9 @@ class SimpleAsyncTaskExecutorTests {
 
 	@Test
 	void throwsExceptionWhenSuppliedWithNullRunnable() {
-		assertThatIllegalArgumentException().isThrownBy(() ->
-				new SimpleAsyncTaskExecutor().execute(null));
+		try (SimpleAsyncTaskExecutor executor = new SimpleAsyncTaskExecutor()) {
+			assertThatIllegalArgumentException().isThrownBy(() -> executor.execute(null));
+		}
 	}
 
 	private void executeAndWait(SimpleAsyncTaskExecutor executor, Runnable task, Object monitor) {
diff --git a/spring-web/src/test/java/org/springframework/web/client/RestClientIntegrationTests.java b/spring-web/src/test/java/org/springframework/web/client/RestClientIntegrationTests.java
index a249ef1dda..217d08bb4a 100644
--- a/spring-web/src/test/java/org/springframework/web/client/RestClientIntegrationTests.java
+++ b/spring-web/src/test/java/org/springframework/web/client/RestClientIntegrationTests.java
@@ -47,7 +47,6 @@ import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.http.client.JdkClientHttpRequestFactory;
 import org.springframework.http.client.JettyClientHttpRequestFactory;
-import org.springframework.http.client.OkHttp3ClientHttpRequestFactory;
 import org.springframework.http.client.ReactorNettyClientRequestFactory;
 import org.springframework.http.client.SimpleClientHttpRequestFactory;
 import org.springframework.util.CollectionUtils;
@@ -77,7 +76,7 @@ class RestClientIntegrationTests {
 		return Stream.of(
 			named("JDK HttpURLConnection", new SimpleClientHttpRequestFactory()),
 			named("HttpComponents", new HttpComponentsClientHttpRequestFactory()),
-			named("OkHttp", new OkHttp3ClientHttpRequestFactory()),
+			named("OkHttp", new org.springframework.http.client.OkHttp3ClientHttpRequestFactory()),
 			named("Jetty", new JettyClientHttpRequestFactory()),
 			named("JDK HttpClient", new JdkClientHttpRequestFactory()),
 			named("Reactor Netty", new ReactorNettyClientRequestFactory())
diff --git a/spring-web/src/test/java/org/springframework/web/client/RestTemplateIntegrationTests.java b/spring-web/src/test/java/org/springframework/web/client/RestTemplateIntegrationTests.java
index 9598da14f5..7e8829e275 100644
--- a/spring-web/src/test/java/org/springframework/web/client/RestTemplateIntegrationTests.java
+++ b/spring-web/src/test/java/org/springframework/web/client/RestTemplateIntegrationTests.java
@@ -50,7 +50,6 @@ import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.http.client.JdkClientHttpRequestFactory;
 import org.springframework.http.client.JettyClientHttpRequestFactory;
-import org.springframework.http.client.OkHttp3ClientHttpRequestFactory;
 import org.springframework.http.client.ReactorNettyClientRequestFactory;
 import org.springframework.http.client.SimpleClientHttpRequestFactory;
 import org.springframework.http.converter.FormHttpMessageConverter;
@@ -96,7 +95,7 @@ class RestTemplateIntegrationTests extends AbstractMockWebServerTests {
 		return Stream.of(
 			named("JDK HttpURLConnection", new SimpleClientHttpRequestFactory()),
 			named("HttpComponents", new HttpComponentsClientHttpRequestFactory()),
-			named("OkHttp", new OkHttp3ClientHttpRequestFactory()),
+			named("OkHttp", new org.springframework.http.client.OkHttp3ClientHttpRequestFactory()),
 			named("Jetty", new JettyClientHttpRequestFactory()),
 			named("JDK HttpClient", new JdkClientHttpRequestFactory()),
 			named("Reactor Netty", new ReactorNettyClientRequestFactory())