001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.conn;
029
030import java.util.concurrent.ExecutionException;
031import java.util.concurrent.TimeUnit;
032
033import org.apache.http.HttpClientConnection;
034import org.apache.http.concurrent.Cancellable;
035
036/**
037 * Represents a request for a {@link HttpClientConnection} whose life cycle
038 * is managed by a connection manager.
039 *
040 * @since 4.3
041 */
042public interface ConnectionRequest extends Cancellable {
043
044    /**
045     * Obtains a connection within a given time.
046     * This method will block until a connection becomes available,
047     * the timeout expires, or the connection manager is shut down.
048     * Timeouts are handled with millisecond precision.
049     *
050     * If {@link #cancel()} is called while this is blocking or
051     * before this began, an {@link InterruptedException} will
052     * be thrown.
053     *
054     * @param timeout   the timeout, 0 or negative for no timeout
055     * @param tunit     the unit for the {@code timeout},
056     *                  may be {@code null} only if there is no timeout
057     *
058     * @return  a connection that can be used to communicate
059     *          along the given route
060     *
061     * @throws ConnectionPoolTimeoutException
062     *         in case of a timeout
063     * @throws InterruptedException
064     *         if the calling thread is interrupted while waiting
065     */
066    HttpClientConnection get(long timeout, TimeUnit tunit)
067        throws InterruptedException, ExecutionException, ConnectionPoolTimeoutException;
068
069}