1 /*

     2  * Copyright 2007-2009 Sun Microsystems, Inc.  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.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package java.nio.channels;

    27 

    28 /**

    29  * A handler for consuming the result of an asynchronous I/O operation.

    30  *

    31  * <p> The asynchronous channels defined in this package allow a completion

    32  * handler to be specified to consume the result of an asynchronous operation.

    33  * The {@link #completed completed} method is invoked when the I/O operation

    34  * completes successfully. The {@link #failed failed} method is invoked if the

    35  * I/O operations fails. The {@link #cancelled cancelled} method is invoked when

    36  * the I/O operation is cancelled by invoking the {@link

    37  * java.util.concurrent.Future#cancel cancel} method. The implementations of

    38  * these methods should complete in a timely manner so as to avoid keeping the

    39  * invoking thread from dispatching to other completion handlers.

    40  *

    41  * @param   <V>     The result type of the I/O operation

    42  * @param   <A>     The type of the object attached to the I/O operation

    43  *

    44  * @since 1.7

    45  */

    46 

    47 public interface CompletionHandler<V,A> {

    48 

    49     /**

    50      * Invoked when an operation has completed.

    51      *

    52      * @param   result

    53      *          The result of the I/O operation.

    54      * @param   attachment

    55      *          The object attached to the I/O operation when it was initiated.

    56      */

    57     void completed(V result, A attachment);

    58 

    59     /**

    60      * Invoked when an operation fails.

    61      *

    62      * @param   exc

    63      *          The exception to indicate why the I/O operation failed

    64      * @param   attachment

    65      *          The object attached to the I/O operation when it was initiated.

    66      */

    67     void failed(Throwable exc, A attachment);

    68 

    69     /**

    70      * Invoked when an operation is cancelled by invoking the {@link

    71      * java.util.concurrent.Future#cancel cancel} method.

    72      *

    73      * @param   attachment

    74      *          The object attached to the I/O operation when it was initiated.

    75      */

    76     void cancelled(A attachment);

    77 }