ntp协议，android获取ntp时间

public static long getNtpTrustedTime(final Context context) {
        try {
            final Class NtpClass = Class
                    .forName("android.util.NtpTrustedTime");

            Object obj = new Object();
            Method method = NtpClass.getMethod("getInstance", Context.class);
            Object gi = method.invoke(obj, context);
            method = NtpClass.getMethod("forceRefresh");
            Object receiverce = method.invoke(gi);
            if ((Boolean) receiverce) {
                method = NtpClass.getMethod("getCachedNtpTime");
                Object cachedNtpTime = method.invoke(gi);
                return (Long) cachedNtpTime;
            }
        } catch (Exception e) {
            Log.d(TAG, e.getMessage());
        }

        return -1;
    }