将时间与当前时间进行比较 [重复]

问：

我正在尝试将主题的时间或开始时间与当前时间进行比较。所以为了简单的解释，这是我想做的。

如果 currentTime 超出 TimeIn，那么我将“late”祝酒，如果不是超出，那么它将启动一个新活动。

在图像中它显示了数据，我正在尝试获取 pSubjtimeIn...

这是我正在尝试的代码......

String getSub = curSubj.getText().toString().trim();

dbref = FirebaseDatabase.getInstance().getReference("Subjects").child(getSub).child("pSubjtimeIn");

dbref.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot snapshot) {

        if (snapshot.exists()) {
//I still got an error here Can't convert object of type java.lang.String to type            
SectionClass data = snapshot.getValue(SectionClass.class);
            if (data != null) {
                String getTime = data.getpSubjtimeIn();
                Toast.makeText(StudentHomePage.this, "" + getTime, Toast.LENGTH_SHORT).show();
                if (getTime != null) {
                    SimpleDateFormat dateFormat = new SimpleDateFormat("h:mm a", Locale.getDefault());
                    Date storedTime = null;
                    try {
                        storedTime = dateFormat.parse(getTime);
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }

                    if (storedTime != null) {
                        Calendar calendar = Calendar.getInstance();
                        Date currentTime = calendar.getTime();

                        calendar.setTime(storedTime);
                        calendar.add(Calendar.MINUTE, 15);
                        Date latetime = calendar.getTime();

                        if (currentTime.after(storedTime) && currentTime.before(latetime)) {
                            Toast.makeText(getApplicationContext(), "Late", Toast.LENGTH_SHORT).show();
                        } else {
                            Intent intent = new Intent(StudentHomePage.this, Present.class);
                            startActivity(intent);
                        }
                    }
                }
            }
        }