Java :Kill process runned by Runtime.getRuntime().exec()

Question

I need to write a code,that

1. run unix process with Runtime.getRuntime().exec("java -jar MyServerRunner -port MYPORT");
2. find PID of the process by executing command from java code lsof -t -i: MYPORT
3. and kill him by pid kill -9 PID ( also by executing command from java code)
4. and then execute others commands

BUT

if I execute this command by Runtime.getRuntime().exec() my program exits with exit code 137 - this means that when I run Runtime.getRuntime().exec("kill -9 PID") I kill process of My java programm, but not the program, that I run from code.

How can I kill ONLY the process that I run from code ?

P.S. maybe I should use ProcessBuilder ?

Solution 1

You can kill a sub-process that you have launched from your java application with destroy:

Process p = Runtime.getRuntime().exec("java -jar MyServerRunner -port MYPORT");
p.destroy();

Also note that it might make sense to run that other code in a separate thread rather than in a separate process.

Solution 2

You can get pid with reflection in unix (I know it is a bad idea :)) and call kill;

Process proc = Runtime.getRuntime().exec(
   new String[] {"java","-classpath",System.getProperty("java.class.path"),... });
Class<?> cProcessImpl = proc.getClass();
Field fPid = cProcessImpl.getDeclaredField("pid");
if (!fPid.isAccessible()) {
    fPid.setAccessible(true);
}
Runtime.getRuntime().exec("kill -9 " + fPid.getInt(proc));

Solution 3

you can use .exec("ps|grep <your process name>");, and then parse the result to get the PID, finally .exec("kill PID");

Therefore, your process is killed but android app still alive.