jps - list the instrumented JVMs on the target system
Note: This command is experimental and unsupported.
jps [-q] [-mlvV] [hostid]
The jps command lists the instrumented Java HotSpot VMs on the target system. The command is limited to reporting information on JVMs for which it has the access permissions.
If the jps command is run without specifying a hostid, then it searches for instrumented JVMs on the local host. If started with a hostid, then it searches 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 reports the local JVM 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, the jps command lists 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 arguments passed to the main method. If the target JVM is started with a custom launcher, then the class or JAR file name, and the arguments to the main method aren't available. In this case, the jps command outputs 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 can be limited by the permissions granted to the principal running the command. The command lists only the JVMs for which the principal has access rights as determined by operating system-specific access control mechanisms.
The host identifier, or hostid, is a string that indicates the target system. The syntax of the hostid string corresponds to the syntax of a URI:
[protocol:][[//]hostname][:port][/servername]
The output of the jps command has the following pattern:
lvmid [ [ classname | JARfilename | "Unknown"] [ arg* ] [ jvmarg* ] ]
All output tokens are separated by white space. An arg value that includes embedded white space introduces ambiguity when attempting to map arguments to their actual positional parameters.
Note:
It's recommended that you don't write scripts to parse jps output because the format might change in future releases. If you write scripts that parse jps output, then expect to modify them for future releases of this tool.
This section provides examples of the jps command.
List the instrumented JVMs on the local host:
jps 18027 Java2Demo.JAR 18032 jps 18005 jstat
The following example lists 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 includes the -l option to output the long form of the class names or JAR file names.
jps -l remote.domain 3002 /opt/jdk1.7.0/demo/jfc/Java2D/Java2Demo.JAR 2857 sun.tools.jstatd.jstatd
The following example lists the instrumented JVMs on a remote host with a nondefault port for the RMI registry. This example assumes that the jstatd server, with an internal RMI registry 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/jdk1.7.0/demo/jfc/Java2D/Java2Demo.JAR 3102 sun.tools.jstatd.jstatd -p 2002