Java proc.waitfor() is being ignored on mac

Question

i ve written a simple program to run on a mac, the program opens an excel file and waits for the the user to close the file after which a simple output is given. when i run the program, excel opens, the proc.waitfor is ignored and it just skips to the output without waiting, any help thanks

  Thread myThread = new Thread() {

        @Override
        public void run() {
            try {
                String userDir = (System.getProperty("user.home"));

                String fileName = userDir + "/Desktop/test/testfile.xlsx";
                File theFile = new File(fileName);
                Process proc = new ProcessBuilder("/usr/bin/open", fileName).start();
                int waitFor = proc.waitFor();
            } catch (InterruptedException ex) {
                Logger.getLogger(MacTester.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(MacTester.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    };

    myThread.start();
    System.out.println("excel is now closed");

Answer 1

This line: System.out.println("excel is now closed");

Should be inside the run method. Your main thread, the thread that is starting your other thread continues with the execution after start has been invoked.

Another alternative is to place: myThread.join();

on the line after: myThread.start();

Answer 2

/usr/bin/open doesn't run modally, it returns the control after launching the appropriate application. You should use open -W. Consider using open -W -n which opens the file in a new instance of the application. Consult man open and try in terminal before testing your java code.