加载类初始化

    private static void parseClassToLoad(XmlPullParser parser) throws Exception {
        String className = parser.nextText();
        // Attempt to load the class so that the class can get initialized
        try {
            Class.forName(className);
        }
        catch (ClassNotFoundException cnfe) {
            System.err.println("Error! A startup class specified in smack-config.xml could " +
                    "not be loaded: " + className);
        }
    }