/* * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/auth/CredentialsProvider.java,v 1.6 2004/07/05 22:46:59 olegk Exp $ * $Revision: 480424 $ * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $ * * ==================================================================== * *  Licensed to the Apache Software Foundation (ASF) under one or more *  contributor license agreements.  See the NOTICE file distributed with *  this work for additional information regarding copyright ownership. *  The ASF licenses this file to You 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. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation.  For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */package org.apache.commons.httpclient.auth;import org.apache.commons.httpclient.Credentials;/** * <p> * Credentials provider interface can be used to provide {@link  * org.apache.commons.httpclient.HttpMethod HTTP method} with a means to request * authentication credentials if no credentials have been given or given * credentials are incorrect. * </p> * <p> * HttpClient makes no provisions to check whether the same credentials have * been tried already. It is a responsibility of the custom credentials provider * to keep track of authentication attempts and to ensure that credentials known * to be invalid are not retried. HttpClient will simply store the set of * credentials returned by the custom credentials provider in the * {@link org.apache.commons.httpclient.HttpState http state} object and will * attempt to use these credentials for all subsequent requests with the given * authentication scope. * </p> * <p> * Classes implementing this interface must synchronize access to shared data as * methods of this interfrace may be executed from multiple threads * </p> *  *  * @author Ortwin Glueck * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a> *  * @since 3.0 */public interface CredentialsProvider {    /**     * Sets the credentials provider parameter.     * <p>     * This parameter expects a value of type {@link CredentialsProvider}.     * </p>     */     public static final String PROVIDER = "http.authentication.credential-provider";        /**     * Requests additional {@link Credentials authentication credentials}.     *      * @param scheme the {@link AuthScheme authentication scheme}     * @param host the authentication host     * @param port the port of the authentication host     * @param proxy <tt>true</tt> if authenticating with a proxy,     *              <tt>false</tt> otherwise     */     public Credentials getCredentials(        final AuthScheme scheme,         final String host,         int port,         boolean proxy) throws CredentialsNotAvailableException; }