restart java app in ubuntu

Question

What's the best way to restart a java app in ubuntu? I know u can run commands like this one from the terminal, but it doesnt seem to be working...

        String restartArgs = "java -jar \'/home/fdqadmin/NetBeansProjects/dbConvert2/dist/dbConvert2.jar\' --Terminal=true";
        Process restart = Runtime.getRuntime().exec(restartArgs);
        System.exit(1);

Answer 1

You are killing the parent process with System.exit(1), so its child process is destroyed as well. To restart you would typically provide a shell script wrapper to launch the actual Java app.

#!/bin/sh
restartCode="1"; # predefined restart signal code
java -jar '/home/fdqadmin/NetBeansProjects/dbConvert2/dist/dbConvert2.jar' --Terminal=true; # run java program
if [ $? -eq restartCode ] # if exit code is equal to predefined restart signal code
then
  $0; # restart script
fi
exit $?;

Note the above code is a rough, crude outline. Typical wrappers are far more complex to deal with commandline arguments passed to the startup script itself etc. etc. Plus, my sh-skills are not infallible.

Answer 2

try providing full path for JAVA_HOME (e.g /usr/lib/jvm/java-6-sun/bin/java instead of java). The exec does not have Shell enironment variables.

also use

 restart.waitFor(); //wait until process finishes 

to make sure Java does not exit before the process finishes.

---

If you do want to run in shell (and use shell specific stuffs like pipe and ls) do this:

List<String> commands = new ArrayList<String>();
commands.add("/bin/sh");
commands.add("-c");
commands.add("java -jar /home/fdqadmin/NetBeansProjects/dbConvert2/dist/dbConvert2.jar");

SystemCommandExecutor commandExecutor = new SystemCommandExecutor(commands);
int result = commandExecutor.executeCommand();
commandExecutor.waitFor(); //wait until process finishes