public void elegirArchivo(View vista){
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    intent.setType("text/*");
    startActivityForResult(intent.createChooser(intent, "Elige una aplicación"),COD_SELECCIONA_TXTART);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    switch (requestCode){
        case COD_SELECCIONA_TXTART:
            Uri datos = data.getData();
            Toast.makeText(this, String.valueOf(datos), Toast.LENGTH_LONG).show();
            break;
    }

private String[] leerArchivo(){
    InputStream inputStream = getResources().openRawResource(R.raw.importararts);
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    try {
        int i = inputStream.read();
        while (i != -1){
            byteArrayOutputStream.write(i);
            i = inputStream.read();
        }
        inputStream.close();
    } catch (IOException e){
        e.printStackTrace();
    }
    return byteArrayOutputStream.toString().split("n");
}