001/*
002 * Copyright (C) 2009 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.util.concurrent;
018
019import java.util.concurrent.Callable;
020
021import javax.annotation.Nullable;
022
023/**
024 * Static utility methods pertaining to the {@link Callable} interface.
025 *
026 * @author Isaac Shum
027 * @since 1.0
028 */
029public final class Callables {
030  private Callables() {}
031
032  /**
033   * Creates a {@code Callable} which immediately returns a preset value each
034   * time it is called.
035   */
036  public static <T> Callable<T> returning(final @Nullable T value) {
037    return new Callable<T>() {
038      @Override public T call() {
039        return value;
040      }
041    };
042  }
043}