我如何計算預定義日期時間和最近日期時間之間的秒數差異

Question

好吧，我正在嘗試定義一個日期，並以秒為單位查看與最近日期的區別。 下面是我在活動的onCreate方法中執行的代碼：

    txtNowTime = (TextView)findViewById(R.id.textViewNow);

    SimpleDateFormat formata = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");

    String currentDateandTime = formata.format(new Date());

    @SuppressWarnings("deprecation")
    Date oldd = new Date("07/18/2014 11:12:13");
    String olddt_frmt = formata.format(oldd);

    long diff =0;
    try {
          Date d_recent = formata.parse("currentDateandTime");

           diff = d_recent.getTime() - oldd.getTime();


        } catch (ParseException ex) {
             ex.printStackTrace();          }

     txtNowTime.setText(String.valueOf(diff));

但是它沒有顯示任何結果。 :-(

Answer 1

改變這個
Date d_recent = formata.parse("currentDateandTime"); 到Date d_recent = formata.parse(currentDateandTime);

Answer 2

請找到答案

SimpleDateFormat formata = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss", Locale.getDefault());
String currentDateandTime = formata.format(new Date());
long diff = 0;
try {
Date d_recent = formata.parse(currentDateandTime);
Date olddt_frmt = formata.parse("07/18/2014 11:12:13");
diff = d_recent.getTime() - olddt_frmt.getTime();
} catch (ParseException ex) {
    ex.printStackTrace();
}

Answer 3

使用Joda-Time看到類似的問題 。 或在Java 8中使用新的java.time包。眾所周知，舊的java.util.Date和.Calendar類很麻煩，應避免。

喬達時間

DateTime then = DateTime.now();
//…
DateTime now = DateTime.now();
Seconds seconds = Seconds.secondsBetween( now, then );
int secondsElapsed = seconds.getSeconds();