yacy_search_server/source/net/yacy/document/parser/htmlParser.java
Michael Peter Christen 765943a4b7 Redesign of crawler identification and robots steering. A non-p2p user
in intranets and the internet can now choose to appear as Googlebot.
This is an essential necessity to be able to compete in the field of
commercial search appliances, since most web pages are these days
optimized only for Google and no other search platform any more. All
commercial search engine providers have a built-in fake-Google User
Agent to be able to get the same search index as Google can do. Without
the resistance against obeying to robots.txt in this case, no
competition is possible any more. YaCy will always obey the robots.txt
when it is used for crawling the web in a peer-to-peer network, but to
establish a Search Appliance (like a Google Search Appliance, GSA) it is
necessary to be able to behave exactly like a Google crawler.
With this change, you will be able to switch the user agent when portal
or intranet mode is selected on per-crawl-start basis. Every crawl start
can have a different user agent.
2013-08-22 14:23:47 +02:00

319 lines
12 KiB
Java

/**
* htmlParser.java
* Copyright 2009 by Michael Peter Christen, mc@yacy.net, Frankfurt am Main, Germany
* First released 09.07.2009 at http://yacy.net
*
* $LastChangedDate$
* $LastChangedRevision$
* $LastChangedBy$
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package net.yacy.document.parser;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.regex.Pattern;
import net.yacy.cora.protocol.ClientIdentification;
import net.yacy.document.AbstractParser;
import net.yacy.document.Document;
import net.yacy.document.Parser;
import net.yacy.document.parser.html.CharacterCoding;
import net.yacy.document.parser.html.ContentScraper;
import net.yacy.document.parser.html.ScraperInputStream;
import net.yacy.document.parser.html.TransformerWriter;
import net.yacy.kelondro.data.meta.DigestURI;
import net.yacy.kelondro.util.FileUtils;
import com.ibm.icu.text.CharsetDetector;
public class htmlParser extends AbstractParser implements Parser {
private static final Pattern patternUnderline = Pattern.compile("_");
private static final int maxLinks = 10000;
public htmlParser() {
super("Streaming HTML Parser");
this.SUPPORTED_EXTENSIONS.add("htm");
this.SUPPORTED_EXTENSIONS.add("html");
this.SUPPORTED_EXTENSIONS.add("phtml");
this.SUPPORTED_EXTENSIONS.add("shtml");
this.SUPPORTED_EXTENSIONS.add("xhtml");
this.SUPPORTED_EXTENSIONS.add("php");
this.SUPPORTED_EXTENSIONS.add("php3");
this.SUPPORTED_EXTENSIONS.add("php4");
this.SUPPORTED_EXTENSIONS.add("php5");
this.SUPPORTED_EXTENSIONS.add("cfm");
this.SUPPORTED_EXTENSIONS.add("asp");
this.SUPPORTED_EXTENSIONS.add("aspx");
this.SUPPORTED_EXTENSIONS.add("tex");
this.SUPPORTED_EXTENSIONS.add("txt");
//SUPPORTED_EXTENSIONS.add("js");
this.SUPPORTED_EXTENSIONS.add("jsp");
this.SUPPORTED_EXTENSIONS.add("mf");
this.SUPPORTED_EXTENSIONS.add("pl");
this.SUPPORTED_EXTENSIONS.add("py");
this.SUPPORTED_MIME_TYPES.add("text/html");
this.SUPPORTED_MIME_TYPES.add("text/xhtml+xml");
this.SUPPORTED_MIME_TYPES.add("application/xhtml+xml");
this.SUPPORTED_MIME_TYPES.add("application/x-httpd-php");
this.SUPPORTED_MIME_TYPES.add("application/x-tex");
this.SUPPORTED_MIME_TYPES.add("text/plain");
this.SUPPORTED_MIME_TYPES.add("text/sgml");
this.SUPPORTED_MIME_TYPES.add("text/csv");
}
@Override
public Document[] parse(
final DigestURI location,
final String mimeType,
final String documentCharset,
final InputStream sourceStream) throws Parser.Failure, InterruptedException {
try {
// first get a document from the parsed html
final ContentScraper scraper = parseToScraper(location, documentCharset, sourceStream, maxLinks);
final Document document = transformScraper(location, mimeType, documentCharset, scraper);
return new Document[]{document};
} catch (final IOException e) {
throw new Parser.Failure("IOException in htmlParser: " + e.getMessage(), location);
}
}
/**
* the transformScraper method transforms a scraper object into a document object
* @param location
* @param mimeType
* @param charSet
* @param scraper
* @return
*/
private static Document transformScraper(final DigestURI location, final String mimeType, final String charSet, final ContentScraper scraper) {
final String[] sections = new String[
scraper.getHeadlines(1).length +
scraper.getHeadlines(2).length +
scraper.getHeadlines(3).length +
scraper.getHeadlines(4).length +
scraper.getHeadlines(5).length +
scraper.getHeadlines(6).length];
int p = 0;
for (int i = 1; i <= 6; i++) {
for (final String headline : scraper.getHeadlines(i)) {
sections[p++] = headline;
}
}
final Document ppd = new Document(
location,
mimeType,
charSet,
scraper,
scraper.getContentLanguages(),
scraper.getKeywords(),
scraper.getTitles(),
scraper.getAuthor(),
scraper.getPublisher(),
sections,
scraper.getDescriptions(),
scraper.getLon(), scraper.getLat(),
scraper.getText(),
scraper.getAnchors(),
scraper.getRSS(),
scraper.getImages(),
scraper.indexingDenied());
ppd.setFavicon(scraper.getFavicon());
return ppd;
}
public static ContentScraper parseToScraper(
final DigestURI location,
final String documentCharset,
InputStream sourceStream,
final int maxLinks) throws Parser.Failure, IOException {
// make a scraper
String charset = null;
// ah, we are lucky, we got a character-encoding via HTTP-header
if (documentCharset != null) {
charset = patchCharsetEncoding(documentCharset);
}
// nothing found: try to find a meta-tag
if (charset == null) {
try {
final ScraperInputStream htmlFilter = new ScraperInputStream(sourceStream, documentCharset, location, null, false, maxLinks);
sourceStream = htmlFilter;
charset = htmlFilter.detectCharset();
htmlFilter.close();
} catch (final IOException e1) {
throw new Parser.Failure("Charset error:" + e1.getMessage(), location);
}
}
// the author didn't tell us the encoding, try the mozilla-heuristic
if (charset == null) {
final CharsetDetector det = new CharsetDetector();
det.enableInputFilter(true);
final InputStream detStream = new BufferedInputStream(sourceStream);
det.setText(detStream);
charset = det.detect().getName();
sourceStream = detStream;
}
// wtf? still nothing, just take system-standard
if (charset == null) {
charset = Charset.defaultCharset().name();
}
Charset c;
try {
c = Charset.forName(charset);
} catch (final IllegalCharsetNameException e) {
c = Charset.defaultCharset();
} catch (final UnsupportedCharsetException e) {
c = Charset.defaultCharset();
}
// parsing the content
final ContentScraper scraper = new ContentScraper(location, maxLinks);
final TransformerWriter writer = new TransformerWriter(null,null,scraper,null,false, Math.max(64, Math.min(4096, sourceStream.available())));
try {
FileUtils.copy(sourceStream, writer, c);
} catch (final IOException e) {
throw new Parser.Failure("IO error:" + e.getMessage(), location);
} finally {
writer.flush();
//sourceStream.close(); keep open for multipe parsing (close done by caller)
writer.close();
}
//OutputStream hfos = new htmlFilterOutputStream(null, scraper, null, false);
//serverFileUtils.copy(sourceFile, hfos);
//hfos.close();
if (writer.binarySuspect()) {
final String errorMsg = "Binary data found in resource";
throw new Parser.Failure(errorMsg, location);
}
return scraper;
}
/**
* some html authors use wrong encoding names, either because they don't know exactly what they
* are doing or they produce a type. Many times, the upper/downcase scheme of the name is fuzzy
* This method patches wrong encoding names. The correct names are taken from
* http://www.iana.org/assignments/character-sets
* @param encoding
* @return patched encoding name
*/
public static String patchCharsetEncoding(String encoding) {
// do nothing with null
if ((encoding == null) || (encoding.length() < 3)) return null;
// trim encoding string
encoding = encoding.trim();
// fix upper/lowercase
encoding = encoding.toUpperCase();
if (encoding.startsWith("SHIFT")) return "Shift_JIS";
if (encoding.startsWith("BIG")) return "Big5";
// all other names but such with "windows" use uppercase
if (encoding.startsWith("WINDOWS")) encoding = "windows" + encoding.substring(7);
if (encoding.startsWith("MACINTOSH")) encoding = "MacRoman";
// fix wrong fill characters
encoding = patternUnderline.matcher(encoding).replaceAll("-");
if (encoding.matches("GB[_-]?2312([-_]80)?")) return "GB2312";
if (encoding.matches(".*UTF[-_]?8.*")) return "UTF-8";
if (encoding.startsWith("US")) return "US-ASCII";
if (encoding.startsWith("KOI")) return "KOI8-R";
// patch missing '-'
if (encoding.startsWith("windows") && encoding.length() > 7) {
final char c = encoding.charAt(7);
if ((c >= '0') && (c <= '9')) {
encoding = "windows-" + encoding.substring(7);
}
}
if (encoding.startsWith("ISO")) {
// patch typos
if (encoding.length() > 3) {
final char c = encoding.charAt(3);
if ((c >= '0') && (c <= '9')) {
encoding = "ISO-" + encoding.substring(3);
}
}
if (encoding.length() > 8) {
final char c = encoding.charAt(8);
if ((c >= '0') && (c <= '9')) {
encoding = encoding.substring(0, 8) + "-" + encoding.substring(8);
}
}
}
// patch wrong name
if (encoding.startsWith("ISO-8559")) {
// popular typo
encoding = "ISO-8859" + encoding.substring(8);
}
// converting cp\d{4} -> windows-\d{4}
if (encoding.matches("CP([_-])?125[0-8]")) {
final char c = encoding.charAt(2);
if ((c >= '0') && (c <= '9')) {
encoding = "windows-" + encoding.substring(2);
} else {
encoding = "windows" + encoding.substring(2);
}
}
return encoding;
}
public static void main(final String[] args) {
// test parsing of a url
DigestURI url;
try {
url = new DigestURI(args[0]);
final byte[] content = url.get(ClientIdentification.yacyInternetCrawlerAgent);
final Document[] document = new htmlParser().parse(url, "text/html", null, new ByteArrayInputStream(content));
final String title = document[0].dc_title();
System.out.println(title);
System.out.println(CharacterCoding.unicode2html(title, false));
} catch (final MalformedURLException e) {
e.printStackTrace();
} catch (final IOException e) {
e.printStackTrace();
} catch (final Parser.Failure e) {
e.printStackTrace();
} catch (final InterruptedException e) {
e.printStackTrace();
}
}
}