problem with running jar from terminal

I try to run

jar -xt jarfile.jar
and I get the message:

jar: operation mode already specified

and of course the file itself is not extracted.
What is wrong?

jar options are pretty much the same as tar options.

You can specify "x" (extract) or you can specify "t" (table of contents), but you can't specify both.

Try this:
jar xvf jarfile.jar

If you are just wanting to execute (run) the jar file
java -jar jarfile.jar