some problen in linking a Java engine to CGOS

CGOS is Server for 9X9 Computer GO (also 19X19)
1,to down load a cgos gtpclient on its website
2,to make a config file, you can get an example file by "gtpclient -s"
3,then, in the config file,
invoke: java -classpath ./:lib/jdom.jar GtpClient
it will make a mistake, for the output do not work,my solution is to
write a shell file "start.sh" which contains a command "java -classpath ./:lib /jdom.jar GtpClient"
then:
invoke: ./start.sh

I'm also confused that why the java command do not work. now I can achive it