com.google.common.util.concurrent.FutureFallback Maven / Gradle / Ivy
/*
* Original Guava code is copyright (C) 2015 The Guava Authors.
* Modifications from Guava are copyright (C) 2015 DiffPlug.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.util.concurrent;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* Provides a backup {@code Future} to replace an earlier failed {@code Future}. An implementation
* of this interface can be applied to an input {@code Future} with {@link Futures#withFallback}.
*
* @param the result type of the provided backup {@code Future}
*
* @author Bruno Diniz
* @since 14.0
* @deprecated This interface's main user, {@link Futures#withFallback(ListenableFuture,
* FutureFallback) Futures.withFallback}, has been updated to use {@link AsyncFunction}. We
* recommend that other APIs be updated in the same way. This interface will be removed in Guava
* release 20.0.
*/
@Beta
@Deprecated
@GwtCompatible
public interface FutureFallback {
/**
* Returns a {@code Future} to be used in place of the {@code Future} that failed with the given
* exception. The exception is provided so that the {@code Fallback} implementation can
* conditionally determine whether to propagate the exception or to attempt to recover.
*
* @param t the exception that made the future fail. If the future's {@link Future#get() get}
* method throws an {@link ExecutionException}, then the cause is passed to this method. Any
* other thrown object is passed unaltered.
*/
ListenableFuture create(Throwable t) throws Exception;
}