org.paxle.parser.tika.impl.ParserContentHandler.java Source code

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Here is the source code for org.paxle.parser.tika.impl.ParserContentHandler.java

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/**
 * This file is part of the Paxle project.
 * Visit http://www.paxle.net for more information.
 * Copyright 2007-2010 the original author or authors.
 *
 * Licensed under the terms of the Common Public License 1.0 ("CPL 1.0").
 * Any use, reproduction or distribution of this program constitutes the recipient's acceptance of this agreement.
 * The full license text is available under http://www.opensource.org/licenses/cpl1.0.txt
 * or in the file LICENSE.txt in the root directory of the Paxle distribution.
 *
 * Unless required by applicable law or agreed to in writing, this software is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 */

package org.paxle.parser.tika.impl;

import java.io.IOException;
import java.io.Writer;
import java.net.URI;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tika.sax.BodyContentHandler;
import org.paxle.core.doc.IParserDocument;
import org.paxle.core.norm.IReferenceNormalizer;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

public class ParserContentHandler extends BodyContentHandler {
    final Log logger = LogFactory.getLog(this.getClass());
    final IReferenceNormalizer refNormalizer;
    final IParserDocument parserDoc;
    final Writer parserDocWriter;
    final URI baseLocation;

    URI currentLink;
    StringBuilder currentLinkText = new StringBuilder();

    public ParserContentHandler(IReferenceNormalizer refNormalizer, URI location, IParserDocument parserDoc)
            throws IOException {
        super(parserDoc.getTextWriter());
        this.refNormalizer = refNormalizer;
        this.baseLocation = location;
        this.parserDoc = parserDoc;
        this.parserDocWriter = parserDoc.getTextWriter();
    }

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes)
            throws SAXException {
        if (localName.equalsIgnoreCase("a") && attributes.getValue("href") != null) {
            final String href = attributes.getValue("href");
            this.currentLink = this.generateURI(href);
        }
        super.startElement(uri, localName, qName, attributes);
    }

    @Override
    public void characters(char[] chars, int start, int length) throws SAXException {
        if (currentLink != null) {
            this.currentLinkText.append(chars, start, length);
        }
        super.characters(chars, start, length);
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if (currentLink != null) {
            this.parserDoc.addReference(this.currentLink, this.currentLinkText.toString(), "HtmlParser");
            this.currentLink = null;
            this.currentLinkText.setLength(0);
        }
        super.endElement(uri, localName, qName);
    }

    private URI generateURI(String href) {
        if (href == null)
            return null;
        else if (href.toLowerCase().startsWith("javascript"))
            return null;
        else if (href.toLowerCase().startsWith("mailto"))
            return null;
        else if (href.startsWith("#"))
            return null;

        try {
            // cut of tailing #
            int pos = href.indexOf('#');
            if (pos != -1) {
                href = href.substring(0, pos);
            }

            // build the URI
            URI uri = null;
            if (!href.contains(":/")) {
                uri = baseLocation.resolve(href);
            } else if (!href.toLowerCase().startsWith("javascript")) {
                uri = new URI(href);
            }

            // Normalize the URI
            if (uri != null) {
                return this.refNormalizer.normalizeReference(uri.toString());
            }
        } catch (Throwable e) {
            this.logger.warn(String.format("Document '%s' contains an invalid href '%s': %s", baseLocation, href,
                    e.getMessage()));
        }
        return null;
    }

    @Override
    public void endDocument() throws SAXException {
        super.endDocument();
        try {
            this.parserDocWriter.flush();
        } catch (IOException e) {
            this.logger.error(
                    String.format("Unexpected %s while parsing %s.", e.getClass().getName(), this.baseLocation), e);
        }
    }
}