Here is what works for me.
uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
in your manifest and the code below
public static boolean createDirIfNotExists(String path) {
boolean ret = true;
File file = new File(Environment.getExternalStorageDirectory(), path);
if (!file.exists()) {
if (!file.mkdirs()) {
Log.e("TravellerLog :: ", "Problem creating Image folder");
ret = false;
}
}
return ret;
}