Protecting or Packing a Jar file to prevent Decompilation.

Jar files(.jar) files produced by normal compilation process offer minimal security against Decompliation
and thus encouraging illegal use of your code.The method described below demonstrates how to
protect your java applications by obfuscation ie:making the code mode complex

One such tool is SmokeScreen Download it from this link given below

Download SmokeScreen_Setup.rar for free on Filesonic.com

Follow these simple steps

• Install Smokescreen and Open it.
• Open the Jar to be packed file by clicking the Browse button in the Source field.
• Give the name of new packed jar file by clicking Browse button in Destination field.
• Click Start Button.Done the File is Packed.
  

http://i52.tinypic.com/33a3y8g.jpg

Utter waste of time.
If someone wants your code, obfuscating it like that will not deter them.

Also, can you guarantee it doesn't effect the footprint of the code? If it does, then not only have you not prevented someone from decompiling your code, but you've just made things worse for your users.