com.datastax.driver.core.utils.MoreFutures Maven / Gradle / Ivy
/*
* Copyright DataStax, 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.datastax.driver.core.utils;
import com.datastax.driver.core.GuavaCompatibility;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
/** Helpers to work with Guava's {@link ListenableFuture}. */
public class MoreFutures {
/** An immediate successful {@code ListenableFuture}. */
public static final ListenableFuture VOID_SUCCESS = Futures.immediateFuture(null);
/** A {@link FutureCallback} that does nothing on failure. */
public abstract static class SuccessCallback implements FutureCallback {
@Override
public void onFailure(Throwable t) {
/* nothing */
}
}
/** A {@link FutureCallback} that does nothing on success. */
public abstract static class FailureCallback implements FutureCallback {
@Override
public void onSuccess(V result) {
/* nothing */
}
}
/**
* Configures a {@link SettableFuture} to propagate the result of a future.
*
* @param settable future to be propagated to
* @param future future to propagate
* @param
*/
public static void propagateFuture(
final SettableFuture settable, ListenableFuture future) {
GuavaCompatibility.INSTANCE.addCallback(
future,
new FutureCallback() {
@Override
public void onSuccess(T result) {
settable.set(result);
}
@Override
public void onFailure(Throwable t) {
settable.setException(t);
}
});
}
}