src/java.base/share/classes/java/util/Locale.java

@@ -631,10 +631,11 @@
      */
     public static final char UNICODE_LOCALE_EXTENSION = 'u';
 
     /** serialization ID
      */
+    @java.io.Serial
     static final long serialVersionUID = 9149081749638150636L;
 
     /**
      * Enum for specifying the type defined in ISO 3166. This enum is used to
      * retrieve the two-letter ISO3166-1 alpha-2, three-letter ISO3166-1

@@ -2299,10 +2300,11 @@
      *      BCP47 private use subtags, all in lower case letters
      *      separated by HYPHEN-MINUS characters.
      *      (See <a href="java.base/java/util/Locale.html#getExtensionKeys()">getExtensionKeys()</a>,
      *      <a href="java.base/java/util/Locale.html#getExtension(char)">getExtension(char)</a>)
      */
+    @java.io.Serial
     private static final ObjectStreamField[] serialPersistentFields = {
         new ObjectStreamField("language", String.class),
         new ObjectStreamField("country", String.class),
         new ObjectStreamField("variant", String.class),
         new ObjectStreamField("hashcode", int.class),

@@ -2314,10 +2316,11 @@
      * Serializes this <code>Locale</code> to the specified <code>ObjectOutputStream</code>.
      * @param out the <code>ObjectOutputStream</code> to write
      * @throws IOException
      * @since 1.7
      */
+    @java.io.Serial
     private void writeObject(ObjectOutputStream out) throws IOException {
         ObjectOutputStream.PutField fields = out.putFields();
         fields.put("language", baseLocale.getLanguage());
         fields.put("script", baseLocale.getScript());
         fields.put("country", baseLocale.getRegion());

@@ -2333,10 +2336,11 @@
      * @throws IOException
      * @throws ClassNotFoundException
      * @throws IllformedLocaleException
      * @since 1.7
      */
+    @java.io.Serial
     private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
         ObjectInputStream.GetField fields = in.readFields();
         String language = (String)fields.get("language", "");
         String script = (String)fields.get("script", "");
         String country = (String)fields.get("country", "");

@@ -2369,10 +2373,11 @@
      *
      * @return an instance of <code>Locale</code> equivalent to
      * the deserialized <code>Locale</code>.
      * @throws java.io.ObjectStreamException
      */
+    @java.io.Serial
     private Object readResolve() throws java.io.ObjectStreamException {
         return getInstance(baseLocale.getLanguage(), baseLocale.getScript(),
                 baseLocale.getRegion(), baseLocale.getVariant(), localeExtensions);
     }