How to open downloaded file in android with default availabe application in android

Question

I am downloading a file from server on completion of download I have to open a file. Know the problem is the file could be of any type so I can't specify and Intent call to open a file with static name like we do to open a PDF file. What I want is when a file is downloaded it will search if any app is available to open the file else it will show pop up. I am doing all this inside fragment. Here my code for downloading :

public class DownloadFile extends AsyncTask<String, Void, Integer> {
    String file_name = "";
    File sdcard = Environment.getExternalStorageDirectory();
    @Override
    protected Integer doInBackground(String... params) {
        // TODO Auto-generated method stub
        try {
            HttpURLConnection url_conn = null;
            byte[] bffr;

            long totalSize = 0;
            File directory = new File(
                    Environment.getExternalStorageDirectory()
                            + "/xyz/download");
            directory.mkdirs();
            // 06-03 17:57:41.160: D/file name(6882):
            file_name = "";
            file_name = params[0];
            Log.d("file name", file_name.toString());
            url_conn = (HttpURLConnection) (new URL("http://example.com/uploads/" + file_name)).openConnection();
            url_conn.setRequestMethod("GET");
            url_conn.setDoOutput(true);
            url_conn.connect();

            if (url_conn.getContentLength() > 0) {
                File imgFile = new File(sdcard + "/xyz/download/",file_name);
                FileOutputStream fos = new FileOutputStream(imgFile);
                InputStream is = url_conn.getInputStream();
                totalSize = url_conn.getContentLength();
                // Log.d("File Download Size ",totalSize+"");
                long total = 0;
                bffr = new byte[1024];
                int bufferLength = 0;
                while ((bufferLength = is.read(bffr)) > 0) {
                    total += bufferLength;
                    publishProgress("" + (int) ((total * 100) / totalSize));
                    fos.write(bffr, 0, bufferLength);
                }
                fos.close();
            } else
                Log.w(file_name.toString(), "FILE NOT FOUND");
            return 0;
        } catch (Exception e) {
            e.printStackTrace();
            return -1;
        }

    }

    private void publishProgress(String... process) {
        // TODO Auto-generated method stub
        mprogressDialog.setProgress(Integer.parseInt(process[0]));
    }

    protected void onPostExecute(Integer unused) {
        Log.d("after downloading file ", "file downloaded ");
        switch (unused) {
        case 0:
            mprogressDialog.dismiss();
             Intent install = new Intent(Intent.ACTION_VIEW);
                install.setDataAndType(Uri.fromFile(new File(sdcard + "/xyz/download/",file_name)),
                        "MIME-TYPE");
                install.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
               app.getBaseContext().startActivity(install);
            break;
        }
    }
}

In post execute I have tried to open it using Intent but that didn't worked. Any Idea is appreciated

Solution

    File file = new File(filePath);
    MimeTypeMap map = MimeTypeMap.getSingleton();
    String ext = MimeTypeMap.getFileExtensionFromUrl(file.getName());
    String type = map.getMimeTypeFromExtension(ext);

    if (type == null)
        type = "*/*";

    Intent intent = new Intent(Intent.ACTION_VIEW);
    Uri data = Uri.fromFile(file);

    intent.setDataAndType(data, type);

    startActivity(intent);