Suppress deprecations for compiling on JDK 19/20

spring-core-test/src/main/java/org/springframework/core/test/tools/DynamicClassLoader.java

@@ -85,15 +85,15 @@ public class DynamicClassLoader extends ClassLoader {
 
 	@Override
 	protected Class<?> findClass(String name) throws ClassNotFoundException {
-		byte[] bytes = findClassBytes(name);
+		Class<?> clazz = defineClass(name, findClassBytes(name));
-		if (bytes != null) {
+		return (clazz != null ? clazz : super.findClass(name));
-			return defineClass(name, bytes);
-		}
-		return super.findClass(name);
 	}
 
-
+	@Nullable
-	private Class<?> defineClass(String name, byte[] bytes) {
+	private Class<?> defineClass(String name, @Nullable byte[] bytes) {
+		if (bytes == null) {
+			return null;
+		}
 		if (this.defineClassMethod != null) {
 			return (Class<?>) ReflectionUtils.invokeMethod(this.defineClassMethod,
 					getParent(), name, bytes, 0, bytes.length);
@@ -142,6 +142,7 @@ public class DynamicClassLoader extends ClassLoader {
 		return (dynamicClassFile != null) ? dynamicClassFile.getBytes() : null;
 	}
 
+	@SuppressWarnings("deprecation")  // on JDK 20
 	private URL createResourceUrl(String name, Supplier<byte[]> bytesSupplier) {
 		try {
 			return new URL(null, "resource:///" + name,

spring-core/src/main/java/org/springframework/util/ConcurrentLruCache.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.
@@ -401,6 +401,7 @@ public final class ConcurrentLruCache<K, V> {
 			}
 		}
 
+		@SuppressWarnings("deprecation")  // for Thread.getId() on JDK 19
 		private static int getBufferIndex() {
 			return ((int) Thread.currentThread().getId()) & BUFFERS_MASK;
 		}
@@ -415,6 +416,7 @@ public final class ConcurrentLruCache<K, V> {
 			return (pending < MAX_PENDING_OPERATIONS);
 		}
 
+		@SuppressWarnings("deprecation")  // for Thread.getId() on JDK 19
 		void drain() {
 			final int start = (int) Thread.currentThread().getId();
 			final int end = start + BUFFER_COUNT;

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

@@ -868,6 +868,7 @@ public abstract class StringUtils {
 	 * @return a corresponding {@code Locale} instance, or {@code null} if none
 	 * @throws IllegalArgumentException in case of an invalid locale specification
 	 */
+	@SuppressWarnings("deprecation")  // for Locale constructors on JDK 19
 	@Nullable
 	public static Locale parseLocaleString(String localeString) {
 		if (localeString.equals("")) {
@@ -877,25 +878,25 @@ public abstract class StringUtils {
 		if (!localeString.contains("_") && localeString.contains(" ")) {
 			delimiter = " ";
 		}
-		final String[] tokens = localeString.split(delimiter, -1);
+		String[] tokens = localeString.split(delimiter, -1);
 		if (tokens.length == 1) {
-			final String language = tokens[0];
+			String language = tokens[0];
 			validateLocalePart(language);
 			return new Locale(language);
 		}
 		else if (tokens.length == 2) {
-			final String language = tokens[0];
+			String language = tokens[0];
 			validateLocalePart(language);
-			final String country = tokens[1];
+			String country = tokens[1];
 			validateLocalePart(country);
 			return new Locale(language, country);
 		}
 		else if (tokens.length > 2) {
-			final String language = tokens[0];
+			String language = tokens[0];
 			validateLocalePart(language);
-			final String country = tokens[1];
+			String country = tokens[1];
 			validateLocalePart(country);
-			final String variant = Arrays.stream(tokens).skip(2).collect(Collectors.joining(delimiter));
+			String variant = Arrays.stream(tokens).skip(2).collect(Collectors.joining(delimiter));
 			return new Locale(language, country, variant);
 		}
 		throw new IllegalArgumentException("Invalid locale format: '" + localeString + "'");