jps - list the instrumented JVMs on the target system
Note: This command is experimental??and unsupported.
- Suppresses the output of the class name, JAR file name, and arguments passed to the
mainmethod, producing a list of only local JVM identifiers.
You can specify any combination of these options.
-mdisplays the arguments passed to the
mainmethod. The output may be
nullfor embedded JVMs.
-ldisplays the full package name for the application's
mainclass or the full path name to the application's JAR file.
-vdisplays the arguments passed to the JVM.
-Vsuppresses the output of the class name, JAR file name, and arguments passed to the
mainmethod, producing a list of only local JVM identifiers.
- The identifier of the host for which the process report should be generated. The
hostidcan include optional components that indicate the communications protocol, port number, and other implementation specific data. See Host Identifier.
- Displays the help message for 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.
JDK 10 added support for using the Attach API when attaching to Java processes running in a separate docker process. However, the
jps tool cannot see JVM processes running in a separate docker instance. If you are trying to connect a Linux host with a Virtual Machine within a docker container, you must use tools such as
ps to look up the PID of the JVM and then specify the PID on the command line of the tools that accept the PID.
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.
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.
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
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:
- The communications protocol. If the protocol is omitted and a hostname isn't specified, then the default protocol is a platform-specific, optimized, local protocol. If the protocol is omitted and a host name is specified, then the default protocol is
- A host name or IP address that indicates the target host. If you omit the hostname parameter, then the target host is the local host.
- The default port for communicating with the remote server. If the hostname parameter is omitted or the protocol parameter specifies an optimized, local protocol, then the port parameter is ignored. Otherwise, treatment of the port parameter is implementation-specific. For the default
rmiprotocol, the port parameter indicates the port number for the
rmiregistryon the remote host. If the port parameter is omitted, and the protocol parameter indicates
rmi, then the default
1099) is used.
- The treatment of this parameter depends on the implementation. For the optimized, local protocol, this field is ignored. For the
rmiprotocol, this parameter is a string that represents the name of the RMI remote object on the remote host. See the jstatd command
Output Format of the jps Command
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.
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
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