text: /*
   * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.io;
  
  import java.lang.annotation.*;
  
  /**
   * Indicates that an annotated field or method is part of the {@linkplain
   * Serializable serialization mechanism} defined by the
   * <cite>Java Object Serialization Specification</cite>. This
   * annotation type is intended to allow compile-time checking of
   * serialization-related declarations, analogous to the checking
   * enabled by the {@link java.lang.Override} annotation type to
   * validate method overriding. {@code Serializable} classes are encouraged to
   * use <code>&#64;Serial</code> annotations to help a compiler catch
   * mis-declared serialization-related fields and methods,
   * mis-declarations that may otherwise be difficult to detect.
   *
   * <p>Specifically, annotations of this type should be
   * applied to serialization-related methods and fields in classes
   * declared to be {@code Serializable}. The five serialization-related
   * methods are:
   *
   * <ul>
   * <li>{@code private void writeObject(java.io.ObjectOutputStream stream) throws IOException}
   * <li>{@code private void readObject(java.io.ObjectInputStream stream) throws IOException, ClassNotFoundException}
   * <li>{@code private void readObjectNoData() throws ObjectStreamException}
   * <li><i>ANY-ACCESS-MODIFIER</i> {@code Object writeReplace() throws ObjectStreamException}
   * <li><i>ANY-ACCESS-MODIFIER</i> {@code Object readResolve() throws ObjectStreamException}
   * </ul>
   *
   * The two serialization-related fields are:
   *
   * <ul>
   * <li>{@code private static final ObjectStreamField[] serialPersistentFields}
   * <li>{@code private static final long serialVersionUID}
   * </ul>
   *
   * Compilers are encouraged to validate that a method or field marked with a
   * <code>&#64;Serial</code> annotation is one of the defined serialization-related
   * methods or fields declared in a meaningful context and issue a warning
   * if that is not the case.
   *
   * <p>It is a semantic error to apply this annotation to other fields or methods, including:
   * <ul>
   * <li>fields or methods in a class that is not {@code Serializable}
   *
   * <li>fields or methods of the proper structural declaration, but in
   * a type where they are ineffectual. For example, {@code enum} types
   * are defined to have a {@code serialVersionUID} of {@code 0L} so a
   * {@code serialVersionUID} field declared in an {@code enum} type is
   * ignored. The five serialization-related methods identified above
   * are likewise ignored for an {@code enum} type.
   *
   * <li>in a class that is {@code Externalizable}:
   * <ul>
   *   <li> method declarations of {@code writeObject}, {@code
   *   readObject}, and {@code readObjectNoData}
   *
   *  <li>a field declaration for {@code serialPersistentFields}
   * </ul>
   *
   * While the {@code Externalizable} interface extends {@code
   * Serializable}, the three methods and one field above are
   * <em>not</em> used for externalizable classes.
   *
   * </ul>
   *
   * Note that serialization mechanism accesses its designated fields
   * and methods reflectively and those fields and methods may appear
   * otherwise unused in a {@code Serializable} class.
   *
   * @see Serializable
   * @see Externalizable
   * @since 14
   */
  @Target({ElementType.METHOD, ElementType.FIELD})
  @Retention(RetentionPolicy.SOURCE)
  public @interface Serial {}
  