[framework] java_signed_applet questino

[Jeffs]

The message in BT4 when running the most recent version of msf3 
(3.3.4-dev.8885)  and java_signed_applet of:

"You must install the Java Development Kit, the rjb ruby gem, and set 
the $JAVA_HOME variable..."

I know I have the Java Development Kit already installed, and I thought 
BT4 has rjb ruby gem installed.

Any help on installing these or verifying if they are installed (other 
than JDK as I know that is installed) for Ubuntu is appreciated.