Options, if used, should follow immediately after the command
name.
heap-dump-file
Java binary heap dump file to be browsed. 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".
The jhat command parses a java heap dump file and
launches a webserver. jhat enables you to browse heap dumps using
your favorite webbrowser. jhat supports pre-designed queries (such
as 'show all instances of a known class "Foo"') as well as
OQL (Object Query Language) - a
SQL-like query language to query heap dumps. Help on OQL is
available from the OQL help page shown by jhat. With the default
port, OQL help is available at http://localhost:7000/oqlhelp/
There are several ways to generate a java heap dump:
Use jmap -dump option to obtain a heap
dump at runtime;
NOTE: This tool is experimental and may not
be available in future versions of the JDK.
OPTIONS
-stackfalse/true
Turn off tracking object allocation call stack. Note that if
allocation site information is not available in the heap dump, you
have to set this flag to false. Default is true.
-refsfalse/true
Turn off tracking of references to objects. Default is true. By
default, back pointers (objects pointing to a given object a.k.a
referrers or in-coming references) are calculated for all objects
in the heap.
-portport-number
Set the port for the jhat's HTTP server. Default is 7000.
-excludeexclude-file
Specify a file that lists data members that should be excluded
from the "reachable objects" query. For example, if the file lists
java.lang.String.value, then, whenever list of objects
reachable from a specific object "o" are calculated, reference
paths involving java.lang.String.value field will not
considered.
-baselinebaseline-dump-file
Specify a baseline heap dump. Objects in both heap dumps with
the same object ID will be marked as not being "new". Other objects
will be marked as "new". This is useful while comparing two
different heap dumps.
-debugint
Set debug level for this tool. 0 means no debug output. Set
higher values for more verbose modes.
-version
Report version number and exit.
-h
Output help message and exit.
-help
Output help message and exit.
-J<flag>
Pass <flag> to the Java virtual machine on which jhat is
run. For example, -J-Xmx512m to use a maximum heap size of
512MB.