hyphenation rules downloiader

HyphenationRulesDownloader.java

package ....;

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashSet;
import java.util.Set;
import android.os.AsyncTask;

/**
 * Created by igor n. boulliev on 22.11.15.
 */
public class HyphenationRulesDownloader {
    private static final String TAG = "HyphenationRulesDownloader";
    private static Set<String> mInDownloading = new HashSet<String>();
    private static synchronized void onFinishDownload(String lang) {
        mInDownloading.remove(lang);
    }
    private static synchronized boolean onStartDownload(String lang) {
        if (mInDownloading.contains(lang)) return false;
        mInDownloading.add(lang);
        return true;
    }

    public static void Download(final Context context, final String lang, final Runnable onFinish) {
        new AsyncTask<Void,Void,Void>() {
            boolean isSuccess = false;
            @SuppressLint("LongLogTag")
            @Override
            protected Void doInBackground(Void... params) {
                if (!onStartDownload(lang)) return null;
                try {
                    URL url = new URL("http://whs.su/bsapp/hr/"+lang+".hyphen.dat");
                    File lf = getLangFile(context, lang);
                    if (!lf.exists()) {
                        if (!lf.createNewFile()) {
                            Log.e(TAG, "could not create file");
                            return null;
                        }
                    }
                    FileOutputStream fos = new FileOutputStream(lf);
                    InputStream body = new BufferedInputStream(url.openStream());
                    byte data[] = new byte[32768];
                    long total = 0;
                    int count;
                    while ((count = body.read(data)) != -1) {
                        total += count;
                        // publishing the progress....
                        fos.write(data, 0, count);
                    }
                    fos.flush();
                    fos.close();
                    body.close();
                    isSuccess = true;

                } catch (MalformedURLException e) {
                    // e.printStackTrace();
                } catch (IOException e) {
                    // e.printStackTrace();
                }
                return null;
            }

            @Override
            protected void onPostExecute(Void result) {
                onFinishDownload(lang);
                if (onFinish!=null && isSuccess)
                    try {
                        onFinish.run();
                    } catch (Exception e) {

                    }
            }
        }.execute();
    }

    public static File getLangFile(Context context, String lang) throws IOException {
        File dataFile = context.getFilesDir();
        File hyphenrulesFile = new File(dataFile,"hr");
        if (!hyphenrulesFile.exists()) {
            if (!hyphenrulesFile.mkdirs()) {
                throw new IOException("cannot create directory for hyphenation rules");
            }
        }
        File langFile = new File(hyphenrulesFile,lang+".dat");
        return langFile;
    }
}