How do I launch another app from Java on a Mac

问题

The code I wrote that works fine on Windows is not working on the Mac. The short form I am calling:

Runtime.getRuntime().exec (String ["/Applications/CM Battle for Normandy/CM Battle for Normandy.app" "2vs2 White Manor 072.ema"], null, "/Applications/CM Battle for Normandy/");

There is no file association setup with .ema files by the software I am trying to run (it's a game if you are curious)

My code looks like this:

    private void launchGameProgram (PBEMGame selectedGame) {
    if (selectedGame == null)
        return; // no work to do

    InstalledProgram program = selectedGame.playedWith ();
    if (program == null)
        return; // no work to do

    try {
        Vector<String> command = new Vector<String> ();
        command.add (program.getExeFile ().getAbsolutePath ());
        if (selectedGame.getLastTurn () != null  &&  selectedGame.getLastTurn ().getTurnFile () != null)  {
            //  Add the turn file name to the command
            command.add (selectedGame.getLastTurn ().getTurnFile ().getName ());
        }
        GUIApplicationPolicy.getLog ().log ("WTII testing: About to launch: " + command.toString () + " from: " + program.getExeFile ().getParentFile ());
        Runtime.getRuntime ().exec (command.toArray (new String[command.size ()]), null, program.getExeFile ().getParentFile ());
    } catch (IOException exception) {
        GUIApplicationPolicy.getLog ().log (exception);
        exception.printStackTrace();
    }
}

This produces the following in the log:

!Entry: 2013/10/02 23:08:33.017
!Message: WTII testing: About to launch: [/Applications/CM Battle for Normandy/CM Battle for Normandy.app, 2vs2 White Manor 072.ema] from: /Applications/CM Battle for Normandy

!Entry: 2013/10/02 23:08:33.023
!Exception: Cannot run program "/Applications/CM Battle for Normandy/CM Battle for Normandy.app" (in directory "/Applications/CM Battle for Normandy"): error=13, Permission denied
!Stack: java.io.IOException: Cannot run program "/Applications/CM Battle for Normandy/CM Battle for Normandy.app" (in directory "/Applications/CM Battle for Normandy"): error=13, Permission denied
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1041)
    at java.lang.Runtime.exec(Runtime.java:617)
    at com.lesliesoftware.whoseturnisit.WhoseTurnIsIt.launchGameProgram(Unknown Source)
    at com.lesliesoftware.whoseturnisit.WhoseTurnIsIt.access$3100(Unknown Source)
    at com.lesliesoftware.whoseturnisit.WhoseTurnIsIt$LaunchSelectedGameProgram.widgetSelected(Unknown Source)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:234)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Display.sendEvent(Display.java:3776)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1367)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1390)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1375)
    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1187)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3622)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3277)
    at com.lesliesoftware.whoseturnisit.WhoseTurnIsIt.main(Unknown Source)
Caused by: java.io.IOException: error=13, Permission denied
    at java.lang.UNIXProcess.forkAndExec(Native Method)
    at java.lang.UNIXProcess.<init>(UNIXProcess.java:135)
    at java.lang.ProcessImpl.start(ProcessImpl.java:130)
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1022)
    ... 14 more

Any help or guidance would be appreciated.

回答1:

Try this..

Runtime.getRuntime().exec (String ["open /Applications/CM Battle for Normandy/CM Battle for Normandy.app" "--args" "2vs2 White Manor 072.ema"], null, "/Applications/CM Battle for Normandy/")

UPDATE: After discussing with Ian..

Runtime.getRuntime().exec (String ["open" "/Applications/CM Battle for Normandy/CM Battle for Normandy.app" "--args" "2vs2 White Manor 072.ema"], null, "/Applications/CM Battle for Normandy/")

回答2:

Is this running things from command line? I see a command variable but I don't see any context regarding what it actually is/does. You may need to add a 'sudo' prefix to whatever command that is (assuming it's in terminal). I'm just inferring that from the Permissions error.

Also, I see a 'getExeFile.' Maybe I'm misunderstanding this but why would you be looking for a .exe on MacOS? Again, I could just be misunderstanding this code. Anyway, I hope this helps or at least helps you jog your brain.

回答3:

You're trying to execute "CM Battle for Normandy.app" and that's a folder (yeah I know can be misleading with the .app extension). What you want to do is to find a binary in that folder and execute that instead. Usually in that folder there's a Contents folder and in it a MacOS folder and in that folder there should be an executable (probably "CM Battle for Normandy").

You can find it with your terminal or Finder.

So my quess is to change:

"/Applications/CM Battle for Normandy/CM Battle for Normandy.app"

To

"/Applications/CM Battle for Normandy/CM Battle for Normandy.app/Contents/MacOS/CM Battle for Normandy"

But it might be slightly different. It does not have end in an extension like on Windows (i.e. .exe or smth) but that's because MacOS is a Unix type system.

来源：https://stackoverflow.com/questions/19456454/how-do-i-launch-another-app-from-java-on-a-mac