final Display display = PlatformUI.createDisplay();
PlatformUI.createAndRunWorkbench(display, new HeadlessAdvisor());

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.
        PlatformUI.getWorkbench().close();
    }

    @Override
    public void postShutdown()
    {
        // This method is called by close(..) after it completes executing, so it is the perfect
        // place to put the notification back to the client.
        super.postShutdown();
        SolsticeClient.getInstance().workbenchCreated();
    }
}