Question

我有两个班级

OTPBroadcastReceiver - 一个扩展BroadcastReceiver并从新到的短信中提取一次性密码（OTP）的类。
OTPListener - 一个实际启动上一个类的类，其中包含回调，应该在收到短信时执行提取OTP。

回调有一个方法onOTPReceived(long timeReceived, final String otp)，由OTPBroadcastReceiver＆amp;它将消息到达的时间传递给long，将OTP消息传递给String。

我的OTPListener中有一个内部类，它有以下成员变量： -

 private class OTPModel {

        long timeReceived = 0L;
        String otp = null;
    }

此类用于存储OTP消息和接收消息的时间。

以下是 OTPListener

import android.content.Context;
import android.support.annotation.NonNull;
import android.widget.Toast;

import java.util.List;

class OTPListener {

    private OTPReceivedInternal mOTPReceivedCallback;
    private OTPModel mOTPModel;


    OTPListener(@NonNull final Context context,
                final List<SMSRule> smsRules,
                @NonNull final CustomOTPView.OnOTPReceivedCallback onOTPReceivedCallback) {

        mOTPModel = new OTPModel();

        mOTPReceivedCallback = new OTPReceivedInternal() {

            @Override
            public void onOTPReceived(long timeReceived, String otp) {

                if (mOTPModel.timeReceived == 0L) {

                    mOTPModel.timeReceived = timeReceived;
                    mOTPModel.otp = otp;
                    onOTPReceivedCallback.onOTPReceived(mOTPModel.otp);
                    System.out.println("First execution");
                    System.out.println("Value of mOTPModel.otp:" + mOTPModel.otp);
                    System.out.println(String.valueOf(mOTPModel.timeReceived));
                } else {

                    if (!mOTPModel.otp.equals(otp)) {
                        if (timeReceived > mOTPModel.timeReceived) {
                            Toast.makeText(context, String.valueOf(timeReceived > mOTPModel.timeReceived),Toast.LENGTH_SHORT).show();
                            mOTPModel.timeReceived = timeReceived;
                            onOTPReceivedCallback.onOTPReceived(mOTPModel.otp = otp);
                            System.out.println("After first execution");
                            System.out.println("{{Value of mOTPModel.timeReceived:" + String.valueOf(mOTPModel.timeReceived));
                            System.out.println("Value of mOTPModel.otp:" + String.valueOf(mOTPModel.otp)+"}}");
                        }
                    }
                }
            }
        };


        new OTPBroadcastReceiver(context,smsRules,mOTPReceivedCallback);
    }

    private class OTPModel {

        long timeReceived = 0L;
        String otp = null;
    }

    protected interface OTPReceivedInternal {

        void onOTPReceived(long timeReceived, String otp);

    }

这里的问题是，

执行第一次，

mOTPModel.timeReceived＆amp; mOTPModel.otp

也都为null

mOTPModel.timeReceived = timeReceived;
mOTPModel.otp = otp;

在我的Android监视器上打印的唯一内容是

System.out.println("First execution");

接下来的两个陈述立即执行。

执行第二次，代码的else部分会被执行，但这次会打印mOTPModel.otp和mOTPModel.timeReceived的旧值后续执行会继续显示以前的值。

这里出了什么问题？为什么 OTPModel 类的成员变量没有被正确分配？

感谢您的时间！

Answer 1

我认为您的问题的原因不在您所显示的代码范围内。监听器在哪里实例化？是否创建了多个实例？

在分配后，您如何确定otp和timeReceived为空？也许这是一个想法来检查otp和timeReceived的传入值（通过调试或更多的日志记录语句）。

没有看到某些System.out.println的事实必须是您的日志记录问题或一些停止该过程的调试/线程问题。

进一步评论：

private OTPReceivedInternal mOTPReceivedCallback;

混淆字段名称，我将其重命名为otpReceivedInternal。特别是因为还有一个名为onOTPReceivedCallback的构造函数参数。

onOTPReceivedCallback.onOTPReceived(mOTPModel.otp = otp);

令人困惑的成语。我把它分成了：

mOTPModel.otp = otp;
onOTPReceivedCallback.onOTPReceived(otp);

这更具可读性。

编辑：所以这就是我现在建议的变化，以找出发生的事情

        @Override
        public void onOTPReceived(long timeReceived, String otp) {

 // print the received values
 System.out.printf("timeReceived = %s, otp = %s", timeReceived, otp);

            if (mOTPModel.timeReceived == 0L) {

                mOTPModel.timeReceived = timeReceived;
                mOTPModel.otp = otp;
                onOTPReceivedCallback.onOTPReceived(mOTPModel.otp);

 // print the mOTPModel values
 System.out.printf("1: mOTPModel.timeReceived = %s, mOTPModel.otp= %s", mOTPModel.timeReceived, mOTPModel.otp);
 System.out.flush();

                // ... carry on

Answer 2

我的猜测：检查onOTPReceived(long timeReceived, String otp)本身收到的值。

如果使用（0，null）调用该方法，我不会感到惊讶;因此你的OTPMOdel对象......以初始值（0，null）开始......之后被“更新”为（0，null）。

内部类成员变量未正确分配

2 个答案: