org.eclipse.jetty.util.Promise Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of aem-sdk-api Show documentation
The Adobe Experience Manager SDK
There is a newer version: 2024.11.18751.20241128T090041Z-241100
// 
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// 
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// 
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// 
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
// 
package org.eclipse.jetty.util;

import java.util.Objects;
import java.util.concurrent.CompletableFuture;
import org.eclipse.jetty.util.log.Log;

/**
 *  A callback abstraction that handles completed/failed events of asynchronous operations.
 *
 *  @param  the type of the context object
 *
 * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
 */
@Deprecated(since = "2021-05-27")
public interface Promise {

    /**
     * Callback invoked when the operation completes.
     *
     * @param result the context
     * @see #failed(Throwable)
     */
    default void succeeded(C result) {
    }

    /**
     * Callback invoked when the operation fails.
     *
     * @param x the reason for the operation failure
     */
    default void failed(Throwable x) {
    }

    /**
     *  Empty implementation of {@link Promise}.
     *
     *  @param  the type of the result
     *
     * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
     */
    @Deprecated(since = "2021-05-27")
    class Adapter implements Promise {

        @Override
        public void failed(Throwable x) {
            Log.getLogger(this.getClass()).warn(x);
        }
    }

    /**
     * Creates a promise from the given incomplete CompletableFuture.
     * When the promise completes, either succeeding or failing, the
     * CompletableFuture is also completed, respectively via
     * {@link CompletableFuture#complete(Object)} or
     * {@link CompletableFuture#completeExceptionally(Throwable)}.
     *
     * @param completable the CompletableFuture to convert into a promise
     * @param  the type of the result
     * @return a promise that when completed, completes the given CompletableFuture
     */
    static  Promise from(CompletableFuture completable) {
        if (completable instanceof Promise)
            return (Promise) completable;
        return new Promise() {

            @Override
            public void succeeded(T result) {
                completable.complete(result);
            }

            @Override
            public void failed(Throwable x) {
                completable.completeExceptionally(x);
            }
        };
    }

    /**
     *  A CompletableFuture that is also a Promise.
     *
     *  @param  the type of the result
     *
     * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
     */
    @Deprecated(since = "2021-05-27")
    class Completable extends CompletableFuture implements Promise {

        @Override
        public void succeeded(S result) {
            complete(result);
        }

        @Override
        public void failed(Throwable x) {
            completeExceptionally(x);
        }
    }

    // @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
    @Deprecated(since = "2021-05-27")
    class Wrapper implements Promise {

        private final Promise promise;

        public Wrapper(Promise promise) {
            this.promise = Objects.requireNonNull(promise);
        }

        @Override
        public void succeeded(W result) {
            promise.succeeded(result);
        }

        @Override
        public void failed(Throwable x) {
            promise.failed(x);
        }

        public Promise getPromise() {
            return promise;
        }

        public Promise unwrap() {
            Promise result = promise;
            while (true) {
                if (result instanceof Wrapper)
                    result = ((Wrapper) result).unwrap();
                else
                    break;
            }
            return result;
        }
    }
}