如何找到外部存储目录

static final String FILE_LOG = "log.txt";

private void SaveLogToExternalStorage()
{
    String s = tv_log.getText().toString();
    File file;
    FileOutputStream fos = null;

    try
    {
        file = new File(getExternalFilesDir(null), FILE_LOG);
        fos = new FileOutputStream(file);
    }
    catch(FileNotFoundException e)
    {
        Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
        return;
    }

    try
    {
        fos.write(s.getBytes());
        fos.close();
    }
    catch(IOException e)
    {
        Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
        return;
    }

    String savedFile = Environment.getExternalStorageDirectory() + "/" + FILE_LOG;
    Toast.makeText(this, "Log is saved to " + savedFile, Toast.LENGTH_SHORT).show();
}

这个函数打印日志将被保存到MNT / SD卡/ log.txt的其实，文件保存到 MNT / SD卡/ Android的/数据/ package.name/files/log.txt 如何编程找到这个目录显示正确的信息？

This function prints Log is saved to mnt/sdcard/log.txt Actually the file is saved to mnt/sdcard/Android/data/package.name/files/log.txt How can I find this directory programmatically to show correct message?