CountDownTimer和ValueEventListener不起作用

Question

从logcat我意识到我的代码中只跳过了countDownTimer，而firebase监听器并不总是正常工作。 知道什么可能是错的吗？

我所要做的就是让我的客户等待雇主回复15秒，如果他在我们继续前进的时间内接受，如果不是我们尝试与列表中的下一个雇主等等。

我的代码：

package com.example.eltobgy.yala.Activities.OrderPackageActivities;
import android.content.Intent;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.os.Handler;
import android.os.Looper;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import com.example.eltobgy.yala.Activities.MainActivity;
import com.example.eltobgy.yala.Models.Package;
import com.example.eltobgy.yala.PackageOnTheWayActivity;
import com.example.eltobgy.yala.R;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.ValueEventListener;

import static com.example.eltobgy.yala.Activities.MainActivity.currentUser;
import static com.example.eltobgy.yala.Activities.MainActivity.mDatabaseUsersReference;

public class WaitingForDeliverymanAcceptanceActivity extends AppCompatActivity {
    private static final String LOG_TAG=WaitingForDeliverymanAcceptanceActivity.class.getSimpleName();
    private int i = 0;
    private String id;
    private DatabaseReference acceptedReference;
    private String onlineSetPackage = "";
    private Package mPackage;
    boolean isAccepted;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_watingfor_deliveryman_acceptance);
        mPackage = (Package) getIntent().getSerializableExtra("package");


        findDeliveryman();
    }

    private void findDeliveryman() {
        Log.e("OrderPackageMapActivity", "entered find delivery man function");

        while (i < OrderPackageMapActivity.onlineDeliveryMenList.size()) {
            id = OrderPackageMapActivity.onlineDeliveryMenList.get(i).getId();

            acceptedReference = MainActivity.mDatabaseOnlineDeliverymenReference.child(id).child("acceptedOrder");
            acceptedReference.addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    if ((boolean) dataSnapshot.getValue() == true) {
                        isAccepted = true;
                        Log.e(LOG_TAG,"isAccepted is true");
                    } else {
                        isAccepted = false;
                        Log.e(LOG_TAG, "isAccepted is false");
                    }
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });

            onlineSetPackage = OrderPackageMapActivity.onlineDeliveryMenList.get(i).getCurrentPackageID();

            DatabaseReference onlineCurrentPackageRef = MainActivity.mDatabaseOnlineDeliverymenReference.child(id).child("currentPackageID");

            if ((onlineSetPackage.equals("")) || (onlineSetPackage == null) || (onlineSetPackage.isEmpty())) {
                onlineCurrentPackageRef.setValue(packageID);
                MainActivity.currentUser.setAttachedDeliveryId(id);
                Log.e(LOG_TAG,"package is set to:"+id);
                CountDownTimer countDownTimer=new CountDownTimer(15000, 1000) {

                    public void onTick(long millisUntilFinished) {
                        //mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
                        //here you can have your logic to set text to edittext
                        Log.e(LOG_TAG,"seconds remaining: " + millisUntilFinished / 1000);
                    }

                    public void onFinish() {
                        checkRequestAcceptance();
                    }

                };
                countDownTimer.start();

            } else {
                i++;
                Log.e("i =", String.valueOf(i));
            }

        }
    }

    private void checkRequestAcceptance() {
        if (isAccepted) {
            Log.e(LOG_TAG, "I accepet");
            mDatabaseUsersReference.child(currentUser.getId()).child("attachedDeliveryId").setValue(id);

            Intent intent = new Intent(WaitingForDeliverymanAcceptanceActivity.this, PackageOnTheWayActivity.class);
            startActivity(intent);
            finish();
        } else {
            Log.e(LOG_TAG, "I refuse");
            i++;
        }

    }

}