获取Android Java中选定日期与当前日期和时间之间的秒数差异？

如何解决获取Android Java中选定日期与当前日期和时间之间的秒数差异？

如何获取选定时间（使用图形化的日期和时间选择器）与现在的日期和时间之间的持续时间（以秒为单位）？

方法getSelectedDate()和getSelectedTime()看起来都不错，选择的日期和时间也很好。但是方法getCountDuration()出问题了。该值不正确。而且我找不到错误。

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";
    int YEAR = 0,DATE = 0,MONTH = 0,HOUR = 0,MINUTE = 0;
    Button dateButton;
    TextView dateTextView,timeTextView,textViewDateAndTime;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        dateButton = findViewById(R.id.dateButton);
        dateTextView = findViewById(R.id.dateTextView);
        timeTextView = findViewById(R.id.timeTextView);

        textViewDateAndTime = findViewById(R.id.textViewDateTimeDuration);

        dateButton.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                getSelectData();
                getSelectTime();
                getCountDuration();
            }
        });
    }

    public LocalDate getSelectData() {

        final Calendar calendarDate = Calendar.getInstance();
        YEAR = calendarDate.get(Calendar.YEAR);
        MONTH = calendarDate.get(Calendar.MONTH);
        DATE = calendarDate.get(Calendar.DATE);
        DatePickerDialog datePickerDialog = new DatePickerDialog(this,new DatePickerDialog.OnDateSetListener() {
            @Override
            public void onDateSet(DatePicker datePicker,int year,int month,int date) {

                Calendar calendar1 = Calendar.getInstance();
                calendar1.set(Calendar.YEAR,year);
                calendar1.set(Calendar.MONTH,month);
                calendar1.set(Calendar.DATE,date);

                String dateText = DateFormat.format("dd.MM.yyyy",calendar1).toString();

                dateTextView.setText(dateText);
            }
        },YEAR,MONTH,DATE);

        datePickerDialog.show();
        return null;
    }

    public LocalTime getSelectTime() {

        Calendar calendar = Calendar.getInstance();
        final LocalDateTime NowIs = LocalDateTime.Now();
        Date currentDate = new Date();
        final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm");//("dd.MM.yyyy HH:mm"
        final LocalDateTime dateTime = currentDate.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();

        HOUR = calendar.get(Calendar.HOUR);
        MINUTE = calendar.get(Calendar.MINUTE);
        boolean is24HourFormat = DateFormat.is24HourFormat(this);

        final TimePickerDialog timePickerDialog = new TimePickerDialog(this,new TimePickerDialog.OnTimeSetListener() {
            @Override
            public void onTimeSet(TimePicker timePicker,int hour,int minute) {
                Log.i(TAG,"onTimeSet: " + hour + minute);
                Calendar calendar1 = Calendar.getInstance();
                calendar1.set(Calendar.HOUR,hour);
                calendar1.set(Calendar.MINUTE,minute);

                String dateText = DateFormat.format("hh:mm",calendar1).toString();
                timeTextView.setText(dateText);
                String dateNowText = formatter.format(dateTime).toString();
            }
        },HOUR,MINUTE,is24HourFormat);

        timePickerDialog.show();
        return null;

    }

    public void getCountDuration() {
        final Calendar setDate = Calendar.getInstance();
        setDate.set(YEAR,DATE,0);
        long subs = Calendar.getInstance().getTimeInMillis() - setDate.getTimeInMillis();
        textViewDateAndTime.setText(subs + " duration in milliseconds");
    }
}