android - 将 ServerValue.TIMESTAMP 转换为日期

Question

我已经放置了一个按钮来将当前日期和时间保存到我的 Firebase 数据库中。

private void saveTime() {
        DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
        rootRef.child(Uid).child("time").setValue(ServerValue.TIMESTAMP);
    }

我正在尝试将服务器日期与我保存在数据库中的日期进行比较。所以请帮我比较一下。

 private void Compare() {

        DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
        DatabaseReference ezzeearnRef = rootRef.child(Uid).child("time");
        ValueEventListener eventListener = new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if (dataSnapshot.exists()) {
                    Long time = dataSnapshot.getValue(Long.class);
                    assert time != null;
                    Date oldDate = new Date(time);
                    GregorianCalendar oldCalendar = new GregorianCalendar();
                    oldCalendar.setTime(oldDate);
                        GregorianCalendar newCalendar = new GregorianCalendar();


                Map<String, String> now = ServerValue.TIMESTAMP;
                newCalendar.setTime((Date) now);

                    if (newCalendar.get(Calendar.DATE) != oldCalendar.get(Calendar.DATE) ||
                            newCalendar.get(Calendar.MONTH) != oldCalendar.get(Calendar.MONTH) ||
                            newCalendar.get(Calendar.YEAR) != oldCalendar.get(Calendar.YEAR)

                            ) {
                        // new day starts toast
                    }


                }else{
                    // toast
                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        };
        ezzeearnRef.addValueEventListener(eventListener);

    }

Answer 1

ServerValue.TIMESTAMP它不是真正的时间戳 Map 所以你不能像这样将它转换为日期

Map<String, String> now = ServerValue.TIMESTAMP;
newCalendar.setTime((Date) now);

时间戳值将从服务器存储