src/java.base/share/classes/java/lang/reflect/UndeclaredThrowableException.java

*** 60,69 ****
--- 60,70 ----
   * @author      Peter Jones
   * @see         InvocationHandler
   * @since       1.3
   */
  public class UndeclaredThrowableException extends RuntimeException {
+     @java.io.Serial
      static final long serialVersionUID = 330127114055056639L;
  
      /**
       * Constructs an {@code UndeclaredThrowableException} with the
       * specified {@code Throwable}.
*** 106,124 ****
--- 107,127 ----
      /**
       * Serializable fields for UndeclaredThrowableException.
       *
       * @serialField undeclaredThrowable Throwable
       */
+     @java.io.Serial
      private static final ObjectStreamField[] serialPersistentFields = {
          new ObjectStreamField("undeclaredThrowable", Throwable.class)
      };
  
      /*
       * Reconstitutes the UndeclaredThrowableException instance from a stream
       * and initialize the cause properly when deserializing from an older
       * version.
       */
+     @java.io.Serial
      private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
          ObjectInputStream.GetField fields = s.readFields();
          Throwable exception = (Throwable) fields.get("undeclaredThrowable", null);
          if (exception != null) {
              SharedSecrets.getJavaLangAccess().setCause(this, exception);
*** 127,136 ****
--- 130,140 ----
  
      /*
       * To maintain compatibility with older implementation, write a serial
       * "ex" field with the cause as the value.
       */
+     @java.io.Serial
      private void writeObject(ObjectOutputStream out) throws IOException {
          ObjectOutputStream.PutField fields = out.putFields();
          fields.put("undeclaredThrowable", super.getCause());
          out.writeFields();
      }