View Full Version : .jar format to MOBI

01-06-2012, 05:10 AM
I have downloaded some books in .jar format but am unable to do anything with them.
I was hoping to convert them to Mobi files to send to my Kindle but it seems Calibre cannot do anything with them.
Also, even if I just "double-click" them all I get it the error message:

"failed to load Main-Class manifest attribute from ****.jar"

Any suggestions anyone??

:help: regards, jojo

01-06-2012, 07:07 AM
Isn't .jar a Java archive (ie. a mobile phone game or utility) ? Try opening one of them with WinRAR or 7-Zip. If there's something that looks like HTML code you should be able to convert it somehow...

If you can't open any, there may be some form of DRM applied to them, I'm not sure. This format isn't very common. It's probably some relic from the pre-Palm and "PDA" days.

01-17-2012, 01:34 PM
.jar is indeed a Java Archive - some books have been packaged up so as to be readable on a mobile phone. The .jar contains effectively the reader and the book.

I would think most books of this sort could be sourced in a "proper" format rather than messing about trying to de-construct the packaging of the .jar.

Gutenberg have a Qioo format that is somewhat similar. I have unzipped a Qioo.jar archive and it contains amongst other things a text file called "data" which is the book in simple text format. As the text contains the usual Gutenberg headers it would be much easier to download the original text !


02-03-2012, 04:08 AM
Thank BobC,
that is very explanatory. think i will look for the proper format in future.