Sometimes we need to show the status message in the RCP application for notifications. The main benefit of showing the status message in RCP application is the fact that its not annoying for the user as no external windows are opened.
Below is the code to display status message in RCP.

/**
     * Shows status message in RCP
     * @param message message to be displayed
     * @param isError if its an error message or normal message
     */
    public static void showStatusMessage(final String message, final boolean isError) {
        Display.getDefault().syncExec(new Runnable() {

            public void run() {
                IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
                if (window instanceof WorkbenchWindow) {
                    WorkbenchWindow w = (WorkbenchWindow) window;
                    if (isError) {
                        w.getStatusLineManager().setErrorMessage(message);
                    } else {
                        w.getStatusLineManager().setMessage(message);
                    }
                }
            }
        });
    }