Tag: subprocess

If you want to run a jar from python or really any process. You do so by leveraging subprocess package.

from subprocess import Popen, PIPE

Then you need to call Popen. If you want to set java memory you can do so using -Xms and -Xmx in between java and -jar.

#bufsize of 1 is line buffered
#stdout and stderr to PIPE is to pipe the output of std out and std error to the PIPE so you can get the output
result = Popen(['java -jar myapp.jar'], stdout=PIPE, stderr=PIPE, shell=False, bufsize=1)

If you want your process to wait until finished you will need to call wait.

result.wait()

If you pushed the stderr and stdout then you can check the output.

if result.stdout is not None:
    for line in result.stdout:
        print(line)

if result.stderr is not None:
    for line in result.stderr:
        print(line)