How to password protect an existing file in linux using java

[kazeopeia]

Hi all,

My original goal was to generate a password protected .xls file using Jasperreports. I was able to do the generation of said file. The problem is the "password protecting" part. I can't seem to find any tool or Api that would do the trick and that linux would accept.

So now I am hoping to find a way to password protect an existing file (any file) in linux instead (using java codes).

Thanks in advance for any suggestion that you could come up with. Please please do help. Thank you.

[dako]

Hi all,

My original goal was to generate a password protected .xls file using Jasperreports. I was able to do the generation of said file. The problem is the "password protecting" part. I can't seem to find any tool or Api that would do the trick and that linux would accept.

So now I am hoping to find a way to password protect an existing file (any file) in linux instead (using java codes).

Thanks in advance for any suggestion that you could come up with. Please please do help. Thank you.

what you really want to do is encrypt the file. Here is a thread from stackoverflow you may find very useful.

stackoverflow.com/questions/5307499/how-to-encrypt-a-file-in-java-using-aes

[nicephotog]

Actually (and for Java), look up the way to do it manually on the terminal in "shell command"
THEN
use System.exec() in your java code in the servlet or program.
System class in Java represents the machine and OS running , the exec is a programmatic command line for the current OS shell.

[Rubberman]

dako has the right idea. You can't really do what you want in Linux. Encrypting the file with something like PGP is a reasonable alternative. I know that Microsoft has the ability to let you password protect any Microsoft Office file, but those are proprietary API's, and just creating an xls file won't let you do that from Linux. Not without a lot of pain and suffering to reverse-engineer their code and encrypted file structures...