check if some folders exists java Android

check if some folders exists java Android

I need check at least 4 directories if they exists and get the correct
path in a variable for finnish my code.
But I don't know the correct way to do that.
Thanks for your help.
Here my code for check a single directory
final String uploadFilePath = "/mnt/sdcard/folder1/";
File f = new File(uploadFilePath);
if(f.exists() && f.isDirectory()){
Log.v("FILES", "EXIST");
}else{
Log.v("FILES", "DONT EXIST");
}