DGN8Parser.java

/*
 * 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.
 */
package org.apache.tika.parser.dgn;

import java.io.IOException;
import java.util.Collections;
import java.util.Set;

import org.apache.poi.poifs.filesystem.DirectoryNode;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

import org.apache.tika.config.TikaComponent;
import org.apache.tika.exception.TikaException;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.parser.microsoft.SummaryExtractor;
import org.apache.tika.sax.XHTMLContentHandler;

/**
 * This is a VERY LIMITED parser. It parses metadata out of dgn8 files.
 */
@TikaComponent
public class DGN8Parser implements Parser {

    Set<MediaType> SUPPORTED_TYPES = Collections.singleton(MediaType.image("vnd.dgn; version=8"));

    @Override
    public Set<MediaType> getSupportedTypes(ParseContext context) {
        return SUPPORTED_TYPES;
    }

    @Override
    public void parse(TikaInputStream tis, ContentHandler handler, Metadata metadata,
                      ParseContext context) throws IOException, SAXException, TikaException {
        XHTMLContentHandler xhtml = new XHTMLContentHandler(handler, metadata, context);
        xhtml.startDocument();
        SummaryExtractor summaryExtractor = new SummaryExtractor(metadata);
        final DirectoryNode root;

        final Object container = tis.getOpenContainer();
        if (container instanceof POIFSFileSystem) {
            root = ((POIFSFileSystem) container).getRoot();
        } else if (container instanceof DirectoryNode) {
            root = (DirectoryNode) container;
        } else {
            POIFSFileSystem fs = null;
            //spool if the container hasn't already been opened;
            fs = new POIFSFileSystem(tis.getFile(), true);

            // tis will close the fs, no need to close this below
            tis.setOpenContainer(fs);
            root = fs.getRoot();
        }

        summaryExtractor.parseSummaries(root);

        xhtml.endDocument();
    }
}