$ jhat -h
Usage: jhat [-stack <bool>] [-refs <bool>] [-port <port>] [-baseline <file>] [-debug <int>] [-version][-h|-help] <file>
-J<flag> Pass <flag> directly to the runtime system. For
example, -J-mx512m to use a maximum heap size of 512MB
-stackfalse: Turn off tracking object allocation call stack.
-refsfalse: Turn off tracking of references to objects
-port <port>: Set the port for the HTTP server. Defaults to 7000
-exclude <file>: Specify a file that lists data members that should
be excluded from the reachableFrom query.
-baseline <file>: Specify a baseline object dump. Objects in
both heap dumps with the same ID and same class will
be marked as not being "new".-debug <int>: Set debug level.
0: No debug output
1: Debug hprof file parsing
2: Debug hprof file parsing, no server
-version Report version number
-h|-help Print this help and exit
<file> The file to read
For a dump file that contains multiple heap dumps,
you may specify which dump in the file
by appending "#<number>" to the file name, i.e. "foo.hprof#3".
All boolean options default to "true"