create an error in j2ee/cluster/server0/log/system/server_00.log

Hello,

for testing purposes i need to create an error log entry in j2ee/cluster/server0/log/system/server_00.log. What do you think is the easiest way to get it done? I think I just can't write an entry in it. What kind of errors can occur and are written in that log? And what would be an easy way to trigger an error situation via program?

Best regards and thanks for your help because i've no clue...

Tobias