public class SolsticeClientApplication implements IApplication
{
    @Override
    // Suppressed due to missing library annotation.
    public Object start(@SuppressWarnings("null") IApplicationContext context) throws Exception
    {
        int okStatus = IApplication.EXIT_OK;

        // It turns out that we have to create the display and the workbench on the main thread of
        // the headless application. It makes sense for the display as the main thread needs to
        // become the UI thread, however for the workbench, if we create an run it in another
        // thread, it just fails without any warning at all.
        final Display display = PlatformUI.createDisplay();
        int retCode = PlatformUI.createAndRunWorkbench(display, new HeadlessAdvisor());

        // Signal that the workbench is created.

        // TODO According to above comment, we are blocking the UI thread until the application
        // is over. Is that alright?
        // I guess this is fine as we are not really using the UI thread in the client
        // application. In any case we should not be invoking any code that uses the UI thread.
        // Rather, we are only using data structures and methods that are in ui packages due to the
        // way they are created, but have nothing to do with the UI thread.
        synchronized (SolsticeClient.getInstance())
        {
            SolsticeClient.getInstance().wait();
        }
        return okStatus;
    }

    @Override
    public void stop()
    {}
}

public class HeadlessAdvisor extends WorkbenchAdvisor
{
    public HeadlessAdvisor()
    {}

    @Override
    public @Nullable
    String getInitialWindowPerspectiveId()
    {
        return null;
    }

    // It turns out that we have to override this method, as it normally does a lot of work in the
    // actual implementation (WorkbenchAdsivor). It would create a full-fledged workbench and then
    // return some boolean representing whether the workbench creation was successful or not.
    // However, in our case, returning 'true' just represents that for our purposes the workbench
    // creation was successful, and we don't create anything.
    @Override
    public boolean openWindows()
    {
        return true;
    }

    @Override
    public void postStartup()
    {
        super.postStartup();
        // close(..) is the call that actually closes the workbench.
        try
        {
            // The following method throws an exception (NullPointer?) in the internal Eclipse code:
            // Workbench:1121 ((IpresentationEngine) engine.stop();) For all our purposes, this
            // exception seems completely harmless as long as it is caught (the workbench still gets
            // closed). I think that this is due to the fact that we are not actually using any
            // workbench elements rather just trying to load the related plug-ins (for later
            // access).
            PlatformUI.getWorkbench().close();
        }
        catch (Exception e)
        {
            // Log the exception.
        }
    }

    @Override
    public void postShutdown()
    {
        // This method is called by close(..)
        super.postShutdown();
    }
}

null
	at org.eclipse.ui.internal.Workbench.busyClose(Workbench.java:1121)
	at org.eclipse.ui.internal.Workbench.access$16(Workbench.java:1001)
	at org.eclipse.ui.internal.Workbench$17.run(Workbench.java:1182)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
	at org.eclipse.ui.internal.Workbench.close(Workbench.java:1180)
	at org.eclipse.ui.internal.Workbench.close(Workbench.java:1153)
	at com.kivancmuslu.www.solstice.client.HeadlessAdvisor.postStartup(HeadlessAdvisor.java:44)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2548)
	at org.eclipse.ui.internal.Workbench.access$7(Workbench.java:2431)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:586)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:543)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at com.kivancmuslu.www.solstice.client.SolsticeClientApplication.start(SolsticeClientApplication.java:85)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1438)