Android无法从doInBackground异步任务中调用外部类的方法

Question

我想从另一个类的doInBackground中的外部方法调用异步电子邮件发送。但总是得到这个异常消息：

01-26 19:01:20.281: E/SMARTT(7131): doInBackground method cannot be processed
01-26 19:01:20.281: E/SMARTT(7131): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()



 protected String doInBackground(Object... params) {
            try {
                Log.i(GlobalApplication.APP_LOG_NAMESPACE,"DOING IN BACKGROUND");
                String typeOfEmail = (String) params[0];
                Map<String, String> data = (Map<String, String>) params[1];
                Log.i(GlobalApplication.APP_LOG_NAMESPACE,data.get("ean"));


                AppHelper helper = new AppHelper();
                helper.sendLogsByEmail(typeOfEmail, data);
                return "test";
            }
            catch (Exception e) {
                Log.e(GlobalApplication.APP_LOG_NAMESPACE,"doInBackground method cannot be processed", e);
                    e.printStackTrace();
                    return null;
                }
        } 

如何从doInBackGround中的另一个类调用方法（如果可能的话）？