001package org.eclipse.aether.transport.http;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 * 
012 *  http://www.apache.org/licenses/LICENSE-2.0
013 * 
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import org.apache.http.HttpResponse;
023import org.apache.http.client.HttpResponseException;
024import org.apache.http.client.methods.HttpUriRequest;
025
026import java.util.Map;
027
028/**
029 * A component extracting included checksums from response of artifact request.
030 *
031 * @since 1.8.0
032 */
033public abstract class ChecksumExtractor
034{
035    /**
036     * Prepares request, if needed.
037     */
038    public void prepareRequest( HttpUriRequest request )
039    {
040        // nothing
041    }
042
043    /**
044     * May control is request to be retried with checksum extractors disabled.
045     */
046    public boolean retryWithoutExtractor( HttpResponseException exception )
047    {
048        return false; // nothing, usually tied to prepareRequest
049    }
050
051    /**
052     * Tries to extract checksums from response headers, if present, otherwise returns {@code null}.
053     */
054    public abstract Map<String, String> extractChecksums( HttpResponse response );
055}