content: /*
   * Copyright (c) 2009, 2013, 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.lang;
  
  /**
   * An object that may hold resources (such as file or socket handles)
   * until it is closed. The {@link #close()} method of an {@code AutoCloseable}
   * object is called automatically when exiting a {@code
   * try}-with-resources block for which the object has been declared in
   * the resource specification header. This construction ensures prompt
   * release, avoiding resource exhaustion exceptions and errors that
   * may otherwise occur.
   *
   * @apiNote
   * <p>It is possible, and in fact common, for a base class to
   * implement AutoCloseable even though not all of its subclasses or
   * instances will hold releasable resources.  For code that must operate
   * in complete generality, or when it is known that the {@code AutoCloseable}
   * instance requires resource release, it is recommended to use {@code
   * try}-with-resources constructions. However, when using facilities such as
   * {@link java.util.stream.Stream} that support both I/O-based and
   * non-I/O-based forms, {@code try}-with-resources blocks are in
   * general unnecessary when using non-I/O-based forms.
   *
   * @author Josh Bloch
   * @since 1.7
   */
  public interface AutoCloseable {
      /**
       * Closes this resource, relinquishing any underlying resources.
       * This method is invoked automatically on objects managed by the
       * {@code try}-with-resources statement.
       *
       * <p>While this interface method is declared to throw {@code
       * Exception}, implementers are <em>strongly</em> encouraged to
       * declare concrete implementations of the {@code close} method to
       * throw more specific exceptions, or to throw no exception at all
       * if the close operation cannot fail.
       *
       * <p> Cases where the close operation may fail require careful
       * attention by implementers. It is strongly advised to relinquish
       * the underlying resources and to internally <em>mark</em> the
       * resource as closed, prior to throwing the exception. The {@code
       * close} method is unlikely to be invoked more than once and so
       * this ensures that the resources are released in a timely manner.
       * Furthermore it reduces problems that could arise when the resource
       * wraps, or is wrapped, by another resource.
       *
       * <p><em>Implementers of this interface are also strongly advised
       * to not have the {@code close} method throw {@link
       * InterruptedException}.</em>
       *
       * This exception interacts with a thread's interrupted status,
       * and runtime misbehavior is likely to occur if an {@code
       * InterruptedException} is {@linkplain Throwable#addSuppressed
       * suppressed}.
       *
       * More generally, if it would cause problems for an
       * exception to be suppressed, the {@code AutoCloseable.close}
       * method should not throw it.
       *
       * <p>Note that unlike the {@link java.io.Closeable#close close}
       * method of {@link java.io.Closeable}, this {@code close} method
       * is <em>not</em> required to be idempotent.  In other words,
       * calling this {@code close} method more than once may have some
       * visible side effect, unlike {@code Closeable.close} which is
       * required to have no effect if called more than once.
       *
       * However, implementers of this interface are strongly encouraged
       * to make their {@code close} methods idempotent.
       *
       * @throws Exception if this resource cannot be closed
       */
      void close() throws Exception;
  }
  