001/* 002 * Copyright (C) 2008 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 005 * use this file except in compliance with the License. You may obtain a copy 006 * 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, WITHOUT 012 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 013 * License for the specific language governing permissions and limitations under 014 * the License. 015 */ 016 017package com.google.common.util.concurrent.testing; 018 019import static com.google.common.util.concurrent.MoreExecutors.directExecutor; 020import static java.util.concurrent.TimeUnit.SECONDS; 021 022import com.google.common.annotations.GwtIncompatible; 023import com.google.common.util.concurrent.ListenableFuture; 024import java.util.concurrent.CountDownLatch; 025import java.util.concurrent.ExecutionException; 026import junit.framework.Assert; 027 028/** 029 * A simple mock implementation of {@code Runnable} that can be used for testing ListenableFutures. 030 * 031 * @author Nishant Thakkar 032 * @since 10.0 033 */ 034@GwtIncompatible 035public class MockFutureListener implements Runnable { 036 private final CountDownLatch countDownLatch; 037 private final ListenableFuture<?> future; 038 039 public MockFutureListener(ListenableFuture<?> future) { 040 this.countDownLatch = new CountDownLatch(1); 041 this.future = future; 042 043 future.addListener(this, directExecutor()); 044 } 045 046 @Override 047 public void run() { 048 countDownLatch.countDown(); 049 } 050 051 /** 052 * Verify that the listener completes in a reasonable amount of time, and Asserts that the future 053 * returns the expected data. 054 * 055 * @throws Throwable if the listener isn't called or if it resulted in a throwable or if the 056 * result doesn't match the expected value. 057 */ 058 public void assertSuccess(Object expectedData) throws Throwable { 059 // Verify that the listener executed in a reasonable amount of time. 060 Assert.assertTrue(countDownLatch.await(1L, SECONDS)); 061 062 try { 063 Assert.assertEquals(expectedData, future.get()); 064 } catch (ExecutionException e) { 065 throw e.getCause(); 066 } 067 } 068 069 /** 070 * Verify that the listener completes in a reasonable amount of time, and Asserts that the future 071 * throws an {@code ExecutableException} and that the cause of the {@code ExecutableException} is 072 * {@code expectedCause}. 073 */ 074 public void assertException(Throwable expectedCause) throws Exception { 075 // Verify that the listener executed in a reasonable amount of time. 076 Assert.assertTrue(countDownLatch.await(1L, SECONDS)); 077 078 try { 079 future.get(); 080 Assert.fail("This call was supposed to throw an ExecutionException"); 081 } catch (ExecutionException expected) { 082 Assert.assertSame(expectedCause, expected.getCause()); 083 } 084 } 085 086 public void assertTimeout() throws Exception { 087 // Verify that the listener does not get called in a reasonable amount of 088 // time. 089 Assert.assertFalse(countDownLatch.await(1L, SECONDS)); 090 } 091}