If u wanna install java game extension *.jar, u must using the file *.jad.
if u dont have the jad file, u can create that by Ur own using TXT editor. follow the steps below
Attributes
MIDlet-Jar-URL: //the name of jar file must be same
MIDlet-Jar-Size: //u can see the size in properties of jar file
MIDlet-Name:
MIDlet-Version:
MIDlet-Vendor:
MIDlet-1:
MicroEdition-Configuration:
MicroEdition-Profile:
U can see the properties using winrar or winzip then open Meta-INF, then extract file MANIFEST.MF then open with notepad.
After u synchronized the attributes, save as in extension jad. see the example below:
MIDlet-Jar-URL: IronMan_SE.jar
MIDlet-Jar-Size: 154306
MIDlet-Name: IRON MAN by Reedim//the name of jar file
MIDlet-Version: 1.0.28
MIDlet-Vendor: handson
MIDlet-1: IRON MAN, /icon.png, Midlet
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-2.0 after finish, save those file to Ur phone. and execute the jad file.
Source: http://aplikasijava.com/cara-mudah-instal-java-game-di-hp-samsung-tanpa-software-apapun/ | 
