com.google.common.util.concurrent.ValueFuture Maven / Gradle / Ivy
/*
* Copyright (C) 2009 Google Inc.
*
* 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 com.google.common.annotations.Beta;
import javax.annotation.Nullable;
/**
* A simple ListenableFuture that holds a value or an exception.
*
* @author Sven Mawson
* @since 1
*/
@Beta
public class ValueFuture extends AbstractListenableFuture {
/**
* Creates a new {@code ValueFuture} in the default state.
*/
public static ValueFuture create() {
return new ValueFuture();
}
/**
* Explicit private constructor, use the {@link #create} factory method to
* create instances of {@code ValueFuture}.
*/
private ValueFuture() {}
/**
* Sets the value of this future. This method will return {@code true} if
* the value was successfully set, or {@code false} if the future has already
* been set or cancelled.
*
* @param newValue the value the future should hold.
* @return true if the value was successfully set.
*/
@Override
public boolean set(@Nullable V newValue) {
return super.set(newValue);
}
/**
* Sets the future to having failed with the given exception. This exception
* will be wrapped in an ExecutionException and thrown from the get methods.
* This method will return {@code true} if the exception was successfully set,
* or {@code false} if the future has already been set or cancelled.
*
* @param t the exception the future should hold.
* @return true if the exception was successfully set.
*/
@Override
public boolean setException(Throwable t) {
return super.setException(t);
}
/**
* {@inheritDoc}
*
* A ValueFuture is never considered in the running state, so the
* {@code mayInterruptIfRunning} argument is ignored.
*/
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
return super.cancel();
}
}