$ java
Usage: java [-options] class [arg1 arg2 ...]
(to run a class file)
or java [-options] -jar jarfile [arg1 arg2 ...]
(to run a standalone jar file)
where options include:
-help print out this message
-version print out version number and copyright information
-showversion show version number and copyright and continue
-cp -classpath <jar/zip files and directories separated by :>
locations where to find application classes
-verbose[:class|gc|jni]
:class print out information about class loading, etc.
:gc print out results of garbage collection
:jni print out native method dynamic resolution
-D<name>=<value> set a system property
-X show help on non-standard options