How to write simple txt file in External Storage

Simple Write data/data/package name/files/sample.txt content into  external storage

public void writeOnInternalStorageDir(Context mContext, String sFileName, String sBody) {
    File file = new File(mContext.getFilesDir(), "FolderName");
    if (!file.exists()) {
        file.mkdir();
    }

    try {
        File gpxfile = new File(file, sFileName);
        if (!gpxfile.exists()) {
            gpxfile.createNewFile();
        }
        FileWriter writer = new FileWriter(gpxfile);
        writer.append(sBody);
        writer.flush();
        writer.close();

    } catch (Exception e) {
        e.printStackTrace();
    }
}

Example :  

writeOnInternalStorageDir(MainActivity.this,"sample.txt","Welcome chandkony.blogspot.com");