We can gain access to the PID of the processes via the handle. The handle.getPid() method returns Long representing the numerical value of the PID. Since it is safer to access the processes through the handle, the importance of this method is limited. It may come in handy when our code wants to give information about itself to some other management tool.

It is a common practice for programs to create a file that has the numeric PID as the name of the file. It may be a requirement that a certain program does not run in multiple processes. In that case, the code writes its own PID file to a specific directory. If a PID file with that name already exists, processing stops. If the previous process crashed or terminated without deleting the PID file, then the system manager can easily delete the file and start the new process. If the program hangs, then the system manager can easily kill the dead process if the PID is known.

To get the PID of the current process, the call chain ProcessHandle.current().getPid() can be used.