io.github.runassudo.gtfs.ZipStreamGTFSFile.java Source code

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Here is the source code for io.github.runassudo.gtfs.ZipStreamGTFSFile.java

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/*
PTOffline: An offline GTFS/public transport app for Android
Copyright  2017  RunasSudo (Yingtong Li)
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program 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 Affero General Public License for more details.
    
You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package io.github.runassudo.gtfs;

import com.google.common.hash.Hashing;

import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

/**
 * Created by runassudo on 19/02/17.
 */

public class ZipStreamGTFSFile extends GTFSFile {
    ZipFile parentFile;
    ZipEntry zipEntry;

    public ZipStreamGTFSFile(ZipFile parentFile, ZipEntry zipEntry) {
        this.parentFile = parentFile;
        this.zipEntry = zipEntry;
    }

    public void iterateThroughContents(IterateThroughContentsCallback callback) throws IOException {
        ZipArchiveInputStream gtfsStream = new ZipArchiveInputStream(parentFile.getInputStream(zipEntry));
        ZipArchiveEntry contentEntry;
        while ((contentEntry = gtfsStream.getNextZipEntry()) != null) {
            callback.call(new ZipStreamGTFSCSV(gtfsStream, contentEntry));
        }
    }

    public FlatGTFSFile toFlatFile() throws IOException {
        File destBase = new File(
                new File(GTFSCollection.cacheDir,
                        Hashing.sha256().hashString(parentFile.getName(), StandardCharsets.UTF_8).toString()),
                Hashing.sha256().hashString(zipEntry.getName(), StandardCharsets.UTF_8).toString());

        if (!destBase.exists()) {
            ZipArchiveInputStream gtfsStream = new ZipArchiveInputStream(parentFile.getInputStream(zipEntry));
            ZipArchiveEntry contentEntry;
            while ((contentEntry = gtfsStream.getNextZipEntry()) != null) {
                // Copy this file to cache
                File dest = new File(destBase, contentEntry.getName());
                dest.getParentFile().mkdirs();
                FileOutputStream os = new FileOutputStream(dest);
                byte[] buf = new byte[4096];
                int len;
                while ((len = gtfsStream.read(buf)) > 0) {
                    os.write(buf, 0, len);
                }
                os.close();
            }
            gtfsStream.close();
        }

        return new FlatGTFSFile(destBase);
    }
}