jps(1)jps(1)NAMEjps - Java Virtual Machine Process Status Tool
SYNOPSISjps [options] [hostid]
DESCRIPTION
The jps tool lists the instrumented HotSpot Java Virtual Machines
(JVMs) on the target system. The tool is limited to reporting informa‐
tion on JVMs for which it has the access permissions.
If jps is run without specifying a hostid, it will look for instru‐
mented JVMs on the local host. If started with a hostid, it will look
for JVMs on the indicated host, using the specified protocol and port.
A jstatd process is assumed to be running on the target host.
The jps command will report the local VM identifier, or lvmid, for each
instrumented JVM found on the target system. The lvmid is typically,
but not necessarily, the operating system's process identifier for the
JVM process. With no options, jps will list each Java application's
lvmid followed by the short form of the application's class name or jar
file name. The short form of the class name or JAR file name omits the
class's package information or the JAR files path information.
The jps command uses the java launcher to find the class name and argu‐
ments passed to the main method. If the target JVM is started with a
custom launcher, the class name (or JAR file name) and the arguments to
the main method will not be available. In this case, the jps command
will output the string Unknown for the class name or JAR file name and
for the arguments to the main method.
The list of JVMs produced by the jps command may be limited by the per‐
missions granted to the principal running the command. The command will
only list the JVMs for which the principle has access rights as deter‐
mined by operating system specific access control mechanisms.
NOTE - This utility is unsupported and may or may not be available in
future versions of the JDK. It is not currently available on Widows 98
and Windows ME platforms.
PARAMETERS
options Command-line options.
hostid The host identifier of the host for which the process
report should be generated. The hostid may include
optional components that indicate the communications
protocol, port number, and other implementation specific
data.
OPTIONS
The jps command supports a number of options that modify the output of
the command. These options are subject to change or removal in the
future.
-q Suppress the output of the class name, JAR file name,
and arguments passed to the main method, producing only
a list of local VM identifiers.
-m Output the arguments passed to the main method. The out‐
put may be null for embedded JVMs.
-l Output the full package name for the application's main
class or the full path name to the application's JAR
file.
-v Output the arguments passed to the JVM.
-V Output the arguments passed to the JVM through the flags
file (the .hotspotrc file or the file specified by the
-XX:Flags=<filename> argument).
-Joption Pass option to the java launcher called by javac. For
example, -J-Xms48m sets the startup memory to 48
megabytes. It is a common convention for -J to pass
options to the underlying VM executing applications
written in Java.
HOST IDENTIFIER
The host identifier, or hostid is a string that indicates the target
system. The syntax of the hostid string largely corresponds to the syn‐
tax of a URI:
[protocol:][[//]hostname][:port][/servername]
protocol The communications protocol. If the protocol is omitted
and a hostname is not specified, the default protocol is
a platform specific, optimized, local protocol. If the
protocol is omitted and a hostname is specified, then
the default protocol is rmi.
hostname A hostname or IP address indicating the target host. If
hostname is omitted, then the target host is the local
host.
port The default port for communicating with the remote
server. If the hostname is omitted or the protocol spec‐
ifies an optimized, local protocol, then port is
ignored. Otherwise, treatment of the port parameter is
implementation specific. For the default rmi protocol
the port indicates the port number for the rmiregistry
on the remote host. If port is omitted, and protocol
indicates rmi, then the default rmiregistry port (1099)
is used.
servername The treatment of this parameter depends on the implemen‐
tation. For the optimized, local protocol, this field is
ignored. For the rmi protocol, this parameter is a
string representing the name of the RMI remote object on
the remote host. See the -n option for the jstatd com‐
mand.
OUTPUT FORMAT
The output of the jps command follows the following pattern:
lvmid [ [ classname | JARfilename | "Unknown"] [ arg* ] [ jvmarg* ] ]
Where all output tokens are separated by white space. An arg that
includes embedded white space will introduce ambiguity when attempting
to map arguments to their actual positional parameters.
NOTE- You are advised not to write scripts to parse jps output since
the format may change in future releases. If you choose to write
scripts that parse jps output, expect to modify them for future
releases of this tool.
EXAMPLES
This section provides examples of the jps command.
Listing the instrumented JVMs on the local host:
jps
18027 Java2Demo.JAR
18032 jps
18005 jstat
Listing the instrumented JVMs on a remote host:
This example assumes that the jstat server and either the its internal
RMI registry or a separate external rmiregistry process are running on
the remote host on the default port (port 1099). It also assumes that
the local host has appropriate permissions to access the remote host.
This example also includes the -l option to output the long form of the
class names or JAR file names.
jps-l remote.domain
3002 /opt/j2sdk1.5.0/demo/jfc/Java2D/Java2Demo.JAR
2857 sun.tools.jstatd.jstatd
Listing the instrumented JVMs on a remote host with a non-default port
for the RMI registry:
This example assumes that the jstatd server, with an internal RMI reg‐
istry bound to port 2002, is running on the remote host. This example
also uses the -m option to include the arguments passed to the main
method of each of the listed Java applications.
jps-m remote.domain:2002
3002 /opt/j2sdk1.5.0/demo/jfc/Java2D/Java2Demo.JAR
3102 sun.tools.jstatd.jstatd -p 2002
SEE ALSOjava(1)jstat(1)jstatd(1)rmiregistry(1)
13 June 2004 jps(1)
