How can my java application get its own PID?

Question

My java application runs under AIX?
The application needs to get its own PID.
There is a possibility to get it by
Runtime.exec("ps -ef | grep <user.name>");
But is there any other alternate possibility?
Any idea would be great appreciated
kind regards

Answer 1

Hello! I found several ways for this in a blog from someone called Igor Minar on
http://net3x.blogspot.com/2007/03/how-java-application-can-discover-its.html
He found several ways:
* Use Java management and monitoring API
ManagementFactory.getRuntimeMXBean().getName();returns something like
1826@localhost
where 1826 is the PID of the JVM process, i.e. my application's process. But this hack is JVM dependent and may not work on JVM's other than Sun's
* Use a shell script to put a property in place that is set to the PID:
exec java -Dpid=$$ -jar myapp.jar* Java Native Interface - cumbersome and platform dependent solution
* Use procfs (Linux solution: read /proc/self, nifty nifty, posted in the comments of the resp. post!)
int pid = Integer.parseInt( ( new File("/proc/self")).getCanonicalFile().getName() );* From another comment: Reflection will work (on Unix): The Process class has a field called pid which can be queried:
static int getPID(Process process) throws IllegalAccessException, IllegalArgumentException,
                                                                  NoSuchFieldException, SecurityException
     Field field = process.getClass().getDeclaredField("pid");
     field.setAccessible(true);
     return field.getInt(process);
}But this solution looks a bit of a kludge to me. I think the /proc/self solution is best - it definitely rox my sox!
Hope this helps!