diff --git a/spring-context/src/main/java/org/springframework/context/support/ReloadableResourceBundleMessageSource.java b/spring-context/src/main/java/org/springframework/context/support/ReloadableResourceBundleMessageSource.java
index 329cb743cf3c..7830eecb7daf 100644
--- a/spring-context/src/main/java/org/springframework/context/support/ReloadableResourceBundleMessageSource.java
+++ b/spring-context/src/main/java/org/springframework/context/support/ReloadableResourceBundleMessageSource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -27,6 +27,7 @@
 import java.util.Properties;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
 import org.springframework.context.ResourceLoaderAware;
@@ -143,7 +144,7 @@ public void setConcurrentRefresh(boolean concurrentRefresh) {
 
 	/**
 	 * Set the PropertiesPersister to use for parsing properties files.
-	 * <p>The default is ResourcePropertiesPersister.
+	 * <p>The default is {@code ResourcePropertiesPersister}.
 	 * @see ResourcePropertiesPersister#INSTANCE
 	 */
 	public void setPropertiesPersister(@Nullable PropertiesPersister propertiesPersister) {
@@ -401,7 +402,7 @@ protected PropertiesHolder getProperties(String filename) {
 
 	/**
 	 * Refresh the PropertiesHolder for the given bundle filename.
-	 * The holder can be {@code null} if not cached before, or a timed-out cache entry
+	 * <p>The holder can be {@code null} if not cached before, or a timed-out cache entry
 	 * (potentially getting re-validated against the current last-modified timestamp).
 	 * @param filename the bundle filename (basename + Locale)
 	 * @param propHolder the current PropertiesHolder for the bundle
@@ -562,7 +563,7 @@ protected class PropertiesHolder {
 
 		private volatile long refreshTimestamp = -2;
 
-		private final ReentrantLock refreshLock = new ReentrantLock();
+		private final Lock refreshLock = new ReentrantLock();
 
 		/** Cache to hold already generated MessageFormats per message code. */
 		private final ConcurrentMap<String, Map<Locale, MessageFormat>> cachedMessageFormats =
diff --git a/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java b/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java
index 2e12a19a3ed3..bfb416e7a9cb 100644
--- a/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java
+++ b/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -26,6 +26,7 @@
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
 import reactor.core.publisher.Mono;
@@ -310,12 +311,10 @@ private class ExpiredSessionChecker {
 		/** Max time between expiration checks. */
 		private static final int CHECK_PERIOD = 60 * 1000;
 
-
-		private final ReentrantLock lock = new ReentrantLock();
+		private final Lock lock = new ReentrantLock();
 
 		private Instant checkTime = clock.instant().plus(CHECK_PERIOD, ChronoUnit.MILLIS);
 
-
 		public void checkIfNecessary(Instant now) {
 			if (this.checkTime.isBefore(now)) {
 				removeExpiredSessions(now);
diff --git a/spring-websocket/src/main/java/org/springframework/web/socket/messaging/SubProtocolWebSocketHandler.java b/spring-websocket/src/main/java/org/springframework/web/socket/messaging/SubProtocolWebSocketHandler.java
index ea90a5797bac..4e1cd54e01db 100644
--- a/spring-websocket/src/main/java/org/springframework/web/socket/messaging/SubProtocolWebSocketHandler.java
+++ b/spring-websocket/src/main/java/org/springframework/web/socket/messaging/SubProtocolWebSocketHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 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.
@@ -25,6 +25,7 @@
 import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.commons.logging.Log;
@@ -98,7 +99,7 @@ public class SubProtocolWebSocketHandler
 
 	private volatile long lastSessionCheckTime = System.currentTimeMillis();
 
-	private final ReentrantLock sessionCheckLock = new ReentrantLock();
+	private final Lock sessionCheckLock = new ReentrantLock();
 
 	private final DefaultStats stats = new DefaultStats();
 
@@ -268,7 +269,7 @@ public Stats getStats() {
 
 	@Override
 	public final void start() {
-		Assert.isTrue(this.defaultProtocolHandler != null || !this.protocolHandlers.isEmpty(), "No handlers");
+		Assert.state(this.defaultProtocolHandler != null || !this.protocolHandlers.isEmpty(), "No handlers");
 
 		synchronized (this.lifecycleMonitor) {
 			this.clientOutboundChannel.subscribe(this);