How can a Java program get its own process ID

Question

How do I get the id of my Java process    I know there are several platform-dependent hacks  but I would prefer a more generic solution

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For older JVM  in linux     private static String getPid   throws IOException       byte   bo   new byte 256       InputStream is   new FileInputStream   proc self stat        is read bo       for  int i   0  i  lt  bo length  i              if   bo i   lt   0       bo i   gt   9                  return new String bo  0  i                       return  -1

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I know this is an old thread  but I wanted to call out that API for getting the PID  as well as other manipulation of the Java process at runtime  is being added to the Process class in JDK 9  http   openjdk java net jeps 102

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This is the code JConsole  and potentially jps and VisualVM uses  It utilizes classes from sun jvmstat monitor   package  from tool jar   package my code a003 process   import sun jvmstat monitor HostIdentifier  import sun jvmstat monitor MonitorException  import sun jvmstat monitor MonitoredHost  import sun jvmstat monitor MonitoredVm  import sun jvmstat monitor MonitoredVmUtil  import sun jvmstat monitor VmIdentifier    public class GetOwnPid        public static void main String   args            new GetOwnPid   run               public void run             System out println getPid this getClass                 public Integer getPid Class lt   gt  mainClass            MonitoredHost monitoredHost          Set lt Integer gt  activeVmPids          try               monitoredHost   MonitoredHost getMonitoredHost new HostIdentifier  String  null                activeVmPids   monitoredHost activeVms                MonitoredVm mvm   null              for  Integer vmPid   activeVmPids                    try                       mvm   monitoredHost getMonitoredVm new VmIdentifier vmPid toString                          String mvmMainClass   MonitoredVmUtil mainClass mvm  true                       if  mainClass getName   equals mvmMainClass                             return vmPid                                          finally                       if  mvm    null                            mvm detach                                                                    catch  java net URISyntaxException e                throw new InternalError e getMessage               catch  MonitorException e                throw new InternalError e getMessage                       return null            There are few catches    The tool jar is a library distributed with Oracle JDK but not JRE   You cannot get tool jar from Maven repo  configure it with Maven is a bit tricky The tool jar probably contains platform dependent  native   code so it is not easily   distributable It runs under assumption that all  local  running JVM apps are  monitorable   It looks like  that from Java 6 all apps generally are  unless you actively configure opposite  It probably works only for Java 6  Eclipse does not publish main class  so you will not get Eclipse PID easily Bug in MonitoredVmUtil    UPDATE  I have just double checked that JPS uses this way  that is Jvmstat library  part of tool jar   So there is no need to call JPS as external process  call Jvmstat library directly as my example shows  You can aslo get list of all JVMs runnin on localhost this way  See JPS source code

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public static long getPID         String processName   java lang management ManagementFactory getRuntimeMXBean   getName        if  processName    null  amp  amp  processName length    gt  0            try               return Long parseLong processName split      0                      catch  Exception e                return 0                       return 0

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It depends on where you are looking for the information from   If you are looking for the information from the console you can use the jps command  The command gives output similar to the Unix ps command and comes with the JDK since I believe 1 5  If you are looking from the process the RuntimeMXBean  as said by Wouter Coekaerts  is probably your best choice  The output from getName   on Windows using Sun JDK 1 6 u7 is in the form  PROCESS ID   MACHINE NAME   You could however try to execute jps and parse the result from that   String jps    JDK HOME       bin  jps exe   Process p   Runtime getRuntime   exec jps     If run with no options the output should be the process id followed by the name

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Here s a backdoor method which might not work with all VMs but should work on both linux and windows  original example here    java lang management RuntimeMXBean runtime        java lang management ManagementFactory getRuntimeMXBean    java lang reflect Field jvm   runtime getClass   getDeclaredField  jvm    jvm setAccessible true   sun management VMManagement mgmt          sun management VMManagement  jvm get runtime   java lang reflect Method pid method         mgmt getClass   getDeclaredMethod  getProcessId    pid method setAccessible true    int pid    Integer  pid method invoke mgmt

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For completeness there is a wrapper in Spring Boot for the   String jvmName   ManagementFactory getRuntimeMXBean   getName    return jvmName split      0     solution  If an integer is required  then this can be summed up to the one-liner   int pid   Integer parseInt ManagementFactory getRuntimeMXBean   getName   split      0      If someone uses Spring boot already  she he might use org springframework boot ApplicationPid  ApplicationPid pid   new ApplicationPid    pid toString      The toString   method prints the pid or         Caveats using the ManagementFactory are discussed in other answers already

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You can check out my project  JavaSysMon on GitHub  It provides process id and a bunch of other stuff  CPU usage  memory usage  cross-platform  presently Windows  Mac OSX  Linux and Solaris

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Try Sigar   very extensive APIs   Apache 2 license   private Sigar sigar   public synchronized Sigar getSigar         if  sigar    null            sigar   new Sigar              return sigar     public synchronized void forceRelease         if  sigar    null            sigar close            sigar   null           public long getPid         return getSigar   getPid

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Here is my solution   public static boolean isPIDInUse int pid             try                String s   null              int java pid               RuntimeMXBean rt   ManagementFactory getRuntimeMXBean                java pid   Integer parseInt rt getName   substring 0  rt getName   indexOf                      if  java pid    pid                    System out println  In Use n                    return true                          catch  Exception e                System out println  Exception       e getMessage                       return false

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I am adding this  in addition to other solutions  with Java 10  to get process id final RuntimeMXBean runtime   ManagementFactory getRuntimeMXBean    final long pid   runtime getPid    out println  quot Process ID is   quot    pid

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This is what I used when I had similar requirement  This determines the PID of the Java process correctly  Let your java code spawn a server on a pre-defined port number and then execute OS commands to find out the PID listening on the port  For Linux  netstat -tupln   grep portNumber

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Based on Ashwin Jayaprakash s answer   1  about the Apache 2 0 licensed SIGAR  here is how I use it to get only the PID of the current process   import org hyperic sigar Sigar   Sigar sigar   new Sigar    long pid   sigar getPid    sigar close      Even though it does not work on all platforms  it does work on Linux  Windows  OS X and various Unix platforms as listed here

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You can try getpid   in JNR-Posix     It has a Windows POSIX wrapper that calls getpid   off of libc

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In Scala   import sys process   val pid  Long   Seq  sh    -c    echo  PPID      trim toLong   This should give you a workaround on Unix systems until Java 9 will be released   I know  the question was about Java  but since there is no equivalent question for Scala  I wanted to leave this for Scala users who might stumble into the same question

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The latest I have found is that there is a system property called sun java launcher pid that is available at least on linux   My plan is to use that and if it is not found to use the JMX bean

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You could use JNA  Unfortunately there is no common JNA API to get the current process ID yet  but each platform is pretty simple   Windows  Make sure you have jna-platform jar then   int pid   Kernel32 INSTANCE GetCurrentProcessId      Unix  Declare   private interface CLibrary extends Library       CLibrary INSTANCE    CLibrary  Native loadLibrary  c   CLibrary class          int getpid         Then   int pid   CLibrary INSTANCE getpid        Java 9  Under Java 9 the new process API can be used to get the current process ID  First you grab a handle to the current process  then query the PID   long pid   ProcessHandle current   pid

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The following method tries to extract the PID from java lang management ManagementFactory   private static String getProcessId final String fallback           Note  may fail in some JVM implementations        therefore fallback has to be provided         something like   lt pid gt   lt hostname gt    at least in SUN   Oracle JVMs     final String jvmName   ManagementFactory getRuntimeMXBean   getName        final int index   jvmName indexOf            if  index  lt  1               part before     empty  index   0        not found  index   -1          return fallback             try           return Long toString Long parseLong jvmName substring 0  index           catch  NumberFormatException e               ignore           return fallback      Just call getProcessId   lt PID gt     for instance

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I found a solution that may be a bit of an edge case and I didn t try it on other OS than Windows 10  but I think it s worth noticing   If you find yourself working with J2V8 and nodejs  you can run a simple javascript function returning you the pid of the java process   Here is an example   public static void main String   args        NodeJS nodeJS   NodeJS createNodeJS        int pid   nodeJS getRuntime   executeIntegerScript  process pid  n        System out println pid       nodeJS release

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There exists no platform-independent way that can be guaranteed to work in all jvm implementations  ManagementFactory getRuntimeMXBean   getName   looks like the best  closest  solution  and typically includes the PID  It s short  and probably works in every implementation in wide use  On linux windows it returns a value like 12345 hostname  12345 being the process id   Beware though that according to the docs  there are no guarantees about this value   Returns the name representing the running Java virtual machine  The returned name string can be any arbitrary string and a Java virtual machine implementation can choose to embed platform-specific useful information in the returned name string  Each running virtual machine could have a different name   In Java 9 the new process API can be used  long pid   ProcessHandle current   pid

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java lang management ManagementFactory getRuntimeMXBean   getName   split      0

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Since Java 9 there is a method Process getPid   which returns the native ID of a process   public abstract class Process                 public long getPid        To get the process ID of the current Java process one can use the ProcessHandle interface   System out println ProcessHandle current   pid

[java] How can a Java program get its own process ID?

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