适用于Azure移动服务的Android客户端中的日期功能

Question

I have an Azure Mobile Service which returns date to an Android Client in this format "Sat Sep 27 22:48:48 PDT 2014"

I want to calculate the difference between this returned date and today's date. After much iterations here is my current function.

 public String calculateDayDifference(String DateFromAzure){

        SimpleDateFormat AzureDateFormat = new SimpleDateFormat("EEE MMM dd H:m:s yyyy");
        Calendar cal = Calendar.getInstance(Locale.getDefault());
        String result;

        try {
           String currentDate = AzureDateFormat.format(System.currentTimeMillis() * 1000L);
           Date presentDate = AzureDateFormat.parse(currentDate);
           Date billDueDate = AzureDateFormat.parse(DateFromAzure);
           long diff = billDueDate.getTime() - presentDate.getTime(); 
           result = Long.toString(diff);
        } catch (ParseException e) {
            result = Long.toString(- 1);
            //e.printStackTrace();
        }
        return  result;
    }

And here is how I call this function from my Adapter's getView() method

 viewHolder.txtNumberDays.setText(mDateFunctions.calculateDayDifference(
                viewHolder.billSummary.getBillDueDate().toString()))

And here is the Java class field that maps to the date column in the Mobile Service table.

  @SerializedName("billDueDate")
    private Date BillDueDate;

No matter how I tweak it, it give me negative result like so. How can I re-write the method above to return the difference between today's date and the date returned from Azure Mobile Service table?

Answer 1

Ok, from the AMS Android SDK source code I can see that the SDK handles formatting and parsing of dates automatically so what is returned is a valid java.util.date object.

https://github.com/Azure/azure-mobile-services/blob/master/sdk/android/src/sdk/src/com/microsoft/windowsazure/mobileservices/DateSerializer.java

With this realization I just called getTime() method on the returned date so I can compare it again current date which can be obtained from System.CurrentTimeMillis(). I then converted the result to int and that was with. Long learning experience. Its not the most efficient way to handle this but it works for. Here is the code

  mBillDueDateService.mBillTable
                .execute(new TableQueryCallback<Bill>() {
            @Override
            public void onCompleted(List<Bill> result, int count,
                                    Exception exception, ServiceFilterResponse response) {
                if (exception == null){
                   for (Bill bill : result){
                       long timeInLong = bill.getBillDueDate().getTime();
                       long currentTime = System.currentTimeMillis();
                       long diffTime = timeInLong - currentTime;
                       long diffDays = diffTime / (1000 * 60 * 60 * 24);
                       int daysdiff = (int) diffDays;
                       Log.i(TAG, "Bill Name " + bill.getBillName() + "" + "Due in " + daysdiff + "days");
                       bill.setDaysBeforeDueDate(daysdiff);
                        mUpcomingBillAdapter.add(bill);
                    }