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.client;
029
030import org.apache.http.protocol.HttpContext;
031
032/**
033 * A handler for determining if the given execution context is user specific
034 * or not. The token object returned by this handler is expected to uniquely
035 * identify the current user if the context is user specific or to be
036 * {@code null} if the context does not contain any resources or details
037 * specific to the current user.
038 * <p>
039 * The user token will be used to ensure that user specific resources will not
040 * be shared with or reused by other users.
041 * </p>
042 *
043 * @since 4.0
044 */
045public interface UserTokenHandler {
046
047    /**
048     * The token object returned by this method is expected to uniquely
049     * identify the current user if the context is user specific or to be
050     * {@code null} if it is not.
051     *
052     * @param context the execution context
053     *
054     * @return user token that uniquely identifies the user or
055     * {@code null} if the context is not user specific.
056     */
057    Object getUserToken(HttpContext context);
058
059}