1 /* 2 * Copyright (c) 2008, 2010, 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 sun.nio.ch; 27 28 import java.util.concurrent.Future; 29 import java.util.concurrent.TimeUnit; 30 import java.util.concurrent.ExecutionException; 31 import java.io.IOException; 32 33 /** 34 * A Future representing the result of an I/O operation that has already 35 * completed. 36 */ 37 38 final class CompletedFuture<V> implements Future<V> { 39 private final V result; 40 private final Throwable exc; 41 CompletedFuture(V result, Throwable exc)42 private CompletedFuture(V result, Throwable exc) { 43 this.result = result; 44 this.exc = exc; 45 } 46 withResult(V result)47 static <V> CompletedFuture<V> withResult(V result) { 48 return new CompletedFuture<V>(result, null); 49 } 50 withFailure(Throwable exc)51 static <V> CompletedFuture<V> withFailure(Throwable exc) { 52 // exception must be IOException or SecurityException 53 if (!(exc instanceof IOException) && !(exc instanceof SecurityException)) 54 exc = new IOException(exc); 55 return new CompletedFuture<V>(null, exc); 56 } 57 withResult(V result, Throwable exc)58 static <V> CompletedFuture<V> withResult(V result, Throwable exc) { 59 if (exc == null) { 60 return withResult(result); 61 } else { 62 return withFailure(exc); 63 } 64 } 65 66 @Override get()67 public V get() throws ExecutionException { 68 if (exc != null) 69 throw new ExecutionException(exc); 70 return result; 71 } 72 73 @Override get(long timeout, TimeUnit unit)74 public V get(long timeout, TimeUnit unit) throws ExecutionException { 75 if (unit == null) 76 throw new NullPointerException(); 77 if (exc != null) 78 throw new ExecutionException(exc); 79 return result; 80 } 81 82 @Override isCancelled()83 public boolean isCancelled() { 84 return false; 85 } 86 87 @Override isDone()88 public boolean isDone() { 89 return true; 90 } 91 92 @Override cancel(boolean mayInterruptIfRunning)93 public boolean cancel(boolean mayInterruptIfRunning) { 94 return false; 95 } 96 } 97