This is for one who need to play java online games from web :D. Many of them (and any other java contained websites) need this plugin enabled on our internet browser, i.e Firefox or Mozilla.
If you have already installed Firefox or Mozilla on your Puppy Linux, you can then install the java plugin (jre-6u17-linux-i586.pet) to support it. Download Java web start plugin here. And then install it.
To use it, it must be enabled/configured.
For Mozilla 1.4 and later, go to Edit > Preferences. Under Advanced category > Select Enable Java.
For Firefox, restart firefox after installing. Go to Tools. Make sure Java console is there. Click Tools -> Add-ons and select plugins category. Enable Java-TM plugins.