1 /*
   2  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.util.stream;
  27 
  28 /**
  29  * A {@code CloseableStream} is a {@code Stream} that can be closed.
  30  * The close method is invoked to release resources that the object is
  31  * holding (such as open files).
  32  *
  33  * @param <T> The type of stream elements
  34  * @since 1.8
  35  */
  36 public interface CloseableStream<T> extends Stream<T>, AutoCloseable {
  37 
  38     /**
  39      * Closes this resource, relinquishing any underlying resources.
  40      * This method is invoked automatically on objects managed by the
  41      * {@code try}-with-resources statement.  Does nothing if called when
  42      * the resource has already been closed.
  43      *
  44      * This method does not allow throwing checked {@code Exception}s like
  45      * {@link AutoCloseable#close() AutoCloseable.close()}. Cases where the
  46      * close operation may fail require careful attention by implementers. It
  47      * is strongly advised to relinquish the underlying resources and to
  48      * internally <em>mark</em> the resource as closed. The {@code close}
  49      * method is unlikely to be invoked more than once and so this ensures
  50      * that the resources are released in a timely manner. Furthermore it
  51      * reduces problems that could arise when the resource wraps, or is
  52      * wrapped, by another resource.
  53      *
  54      * @see AutoCloseable#close()
  55      */
  56     void close();
  57 }