New to Java

i've been doing java project this last 3 months and this my first java project

here's my problem:
ive created an exe from my jar
and that exe should've read some file just say it ".tes"

if i run the exe, i know which .tes that should be read
but if i double click the other ".tes" file, it should've been running the exe and read the .tes i double click on it

but my problem is, the exe cant run, its like i cant file the other library file
but if i put the .tes on the sampe path where the exe and the needed library, its run perfectly

it should've been minor issue i miss
but i dunno how to fix it..

anybody get clue..or some link maybe so i can read it to help me with this problem
thanks guys

cheers ^^