java - Install4j - How to get current version when upgrading -

any 1 know how determine current installed version of app installed install4j. idea figure out installed , control if upgrade possible based on version installed.

thanks

you can use applicationregistry api purpose. here example code snippet used in "run script" action in "startup" node prevent installation if current version installed:

// value returned context.getinstallationdirectory() // last installation directory // if user has installed application applicationregistry.applicationinfo applicationinfo =     applicationregistry.getapplicationinfobydir(context.getinstallationdirectory());  if (applicationinfo == null) {   // application has never been installed before     return true; }  // version of installer contained in system installer variable string myversion = (string)context.getvariable("sys.version"); if (applicationinfo.getversion().equals(myversion)) {     // in case current version installed.     util.showerrormessage("the current version installed in directory");     // returning "false", action fail , installer quit.     // note have set "failure strategy" property of     // "run script" action "quit on error", otherwise installer continue.     return false; } else {     return true; }