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

*** 3868,3877 ****
--- 3868,3878 ----
       * {@code posPrefixPattern} etc.  As a result, they will be initialized
       * to {@code null}, which means the affix strings will be taken as
       * literal values.  This is exactly what we want, since that corresponds to
       * the pre-version-2 behavior.
       */
+     @java.io.Serial
      private void readObject(ObjectInputStream stream)
           throws IOException, ClassNotFoundException
      {
          stream.defaultReadObject();
          digitList = new DigitList();
*** 4341,4347 ****
--- 4342,4349 ----
      // Upper limit on integer and fraction digits for BigDecimal and BigInteger
      static final int MAXIMUM_INTEGER_DIGITS  = Integer.MAX_VALUE;
      static final int MAXIMUM_FRACTION_DIGITS = Integer.MAX_VALUE;
  
      // Proclaim JDK 1.1 serial compatibility.
+     @java.io.Serial
      static final long serialVersionUID = 864413376551465018L;
  }