src/java.base/share/classes/java/text/NumberFormat.java

*** 1011,1020 ****
--- 1011,1021 ----
       * In addition, if any of these values is negative, then this method throws
       * an <code>InvalidObjectException</code>.
       *
       * @since 1.2
       */
+     @java.io.Serial
      private void readObject(ObjectInputStream stream)
           throws IOException, ClassNotFoundException
      {
          stream.defaultReadObject();
          if (serialVersionOnStream < 1) {
*** 1039,1048 ****
--- 1040,1050 ----
       * (or to <code>Byte.MAX_VALUE</code>, whichever is smaller), for compatibility
       * with the JDK 1.1 version of the stream format.
       *
       * @since 1.2
       */
+     @java.io.Serial
      private void writeObject(ObjectOutputStream stream)
           throws IOException
      {
          maxIntegerDigits = (maximumIntegerDigits > Byte.MAX_VALUE) ?
                             Byte.MAX_VALUE : (byte)maximumIntegerDigits;
*** 1223,1232 ****
--- 1225,1235 ----
       */
      private int serialVersionOnStream = currentSerialVersion;
  
      // Removed "implements Cloneable" clause.  Needs to update serialization
      // ID for backward compatibility.
+     @java.io.Serial
      static final long serialVersionUID = -2308460125733713944L;
  
  
      //
      // class for AttributedCharacterIterator attributes
*** 1240,1249 ****
--- 1243,1253 ----
       * @since 1.4
       */
      public static class Field extends Format.Field {
  
          // Proclaim serial compatibility with 1.4 FCS
+         @java.io.Serial
          private static final long serialVersionUID = 7494728892700160890L;
  
          // table of all instances in this class, used by readResolve
          private static final Map<String, Field> instanceMap = new HashMap<>(11);
  
*** 1265,1274 ****
--- 1269,1279 ----
           *
           * @throws InvalidObjectException if the constant could not be resolved.
           * @return resolved NumberFormat.Field constant
           */
          @Override
+         @java.io.Serial
          protected Object readResolve() throws InvalidObjectException {
              if (this.getClass() != NumberFormat.Field.class) {
                  throw new InvalidObjectException("subclass didn't correctly implement readResolve");
              }