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 jetty-util Show documentation

Utility classes for Jetty

There is a newer version: 12.0.13

//
//  ========================================================================
//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  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 org.eclipse.jetty.util.log.Log;

/**
 * A callback abstraction that handles completed/failed events of asynchronous operations.
 *
 * @param  the type of the context object
 */
public interface Promise
{
    /**
     * Callback invoked when the operation completes.
     *
     * @param result the context
     * @see #failed(Throwable)
     */
    public abstract void succeeded(C result);

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

    /**
     * Empty implementation of {@link Promise}
     *
     * @param  the type of the context object
     */
    public static class Adapter implements Promise
    {
        @Override
        public void succeeded(C result)
        {
        }

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

}