为什么方法SimCardInfo.getImsi()在真机上会报错解决方法

public MyApp() {        byte[] imsi = null;        byte[] imei = null;            imei = GPRSInfo.getIMEI();            try {                imsi = SIMCardInfo.getIMSI();            } catch (SIMCardException e) {                e.printStackTrace();            }        MyScreen myScreen = new MyScreen();        myScreen.add(new LabelField("imsi : " + imsi + "imei : "                + imei));        pushScreen(myScreen);    }