thanks, i'll try this app. anyway my original question was :
is there a possibility for the file to be still there, but non browsable because it's like i've openned a new account ?
is Java MODE_PRIVATE acting as a read right, making a security access to the file ?
Looks like your issue after reboot is memory damaged.. Are you using memory in your HTC phone and then you save your files from wallet into your memory card.. maybe your was damaged or you formatted your memory card i think if its formatted all files in memory card will be deleted but the phone memory will not deleted. only files in memory that is why i think you are still had some of your files in your phone because only memory card was formatted..
I just asked this already with my tech friends and if memory formatted and no files you can be still recover files because memory card has extra bytes space for savings some records. so there is possibility that your file for your wallet is still there but its not browsable you mean. but if you recover them you can transfer them back to your wallet path and get back your bitcoin wallet..