org.apache.maven.wagon.shared.http.HtmlFileListParser.java Source code

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Here is the source code for org.apache.maven.wagon.shared.http.HtmlFileListParser.java

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package org.apache.maven.wagon.shared.http;

/*
 * 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.
 */

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.maven.wagon.TransferFailedException;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;

/**
 * Html File List Parser.
 */
public class HtmlFileListParser {
    // Apache Fancy Index Sort Headers
    private static final Pattern APACHE_INDEX_SKIP = Pattern.compile("\\?[CDMNS]=.*");

    // URLs with excessive paths.
    private static final Pattern URLS_WITH_PATHS = Pattern.compile("/[^/]*/");

    // URLs that to a parent directory.
    private static final Pattern URLS_TO_PARENT = Pattern.compile("\\.\\./");

    // mailto urls
    private static final Pattern MAILTO_URLS = Pattern.compile("mailto:.*");

    private static final Pattern[] SKIPS = new Pattern[] { APACHE_INDEX_SKIP, URLS_WITH_PATHS, URLS_TO_PARENT,
            MAILTO_URLS };

    /**
     * Fetches a raw HTML from a provided InputStream, parses it, and returns the file list.
     *
     * @param stream the input stream.
     * @return the file list.
     * @throws TransferFailedException if there was a problem fetching the raw html.
     */
    public static List<String> parseFileList(String baseurl, InputStream stream) throws TransferFailedException {
        try {
            URI baseURI = new URI(baseurl);
            // to make debugging easier, start with a string. This is assuming UTF-8, which might not be a safe
            // assumption.
            String content = IOUtils.toString(stream, "utf-8");
            Document doc = Jsoup.parse(content, baseurl);
            Elements links = doc.select("a[href]");
            Set<String> results = new HashSet<String>();
            for (Element link : links) {
                /*
                 * The abs:href loses directories, so we deal with absolute paths ourselves below in cleanLink
                 */
                String target = link.attr("href");
                if (target != null) {
                    String clean = cleanLink(baseURI, target);
                    if (isAcceptableLink(clean)) {
                        results.add(clean);
                    }
                }

            }

            return new ArrayList<String>(results);
        } catch (URISyntaxException e) {
            throw new TransferFailedException("Unable to parse as base URI: " + baseurl, e);
        } catch (IOException e) {
            throw new TransferFailedException("I/O error reading HTML listing of artifacts: " + e.getMessage(), e);
        }
    }

    private static String cleanLink(URI baseURI, String link) {
        if (StringUtils.isEmpty(link)) {
            return "";
        }

        String ret = link;

        try {
            URI linkuri = new URI(ret);
            if (link.startsWith("/")) {
                linkuri = baseURI.resolve(linkuri);
            }
            URI relativeURI = baseURI.relativize(linkuri).normalize();
            ret = relativeURI.toASCIIString();
            if (ret.startsWith(baseURI.getPath())) {
                ret = ret.substring(baseURI.getPath().length());
            }

            ret = URLDecoder.decode(ret, "UTF-8");
        } catch (URISyntaxException e) {
        } catch (UnsupportedEncodingException e) {
        }

        return ret;
    }

    private static boolean isAcceptableLink(String link) {
        if (StringUtils.isEmpty(link)) {
            return false;
        }

        for (Pattern pattern : SKIPS) {
            if (pattern.matcher(link).find()) {
                return false;
            }
        }

        return true;
    }

}