1 /* 2 * Copyright (C) 2009 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.util.concurrent; 18 19 import java.util.concurrent.Callable; 20 21 import javax.annotation.Nullable; 22 23 /** 24 * Static utility methods pertaining to the {@link Callable} interface. 25 * 26 * @author Isaac Shum 27 * @since 2009.09.15 <b>tentative</b> 28 */ 29 public final class Callables { Callables()30 private Callables() {} 31 32 /** 33 * Creates a {@code Callable} which immediately returns a preset value each 34 * time it is called. 35 */ returning(final @Nullable T value)36 public static <T> Callable<T> returning(final @Nullable T value) { 37 return new Callable<T>() { 38 /*@Override*/ public T call() { 39 return value; 40 } 41 }; 42 } 43 } 44