[JAVA] 時間格式計算

一些簡單的code紀錄一下.
計算時間差的程式碼.

//import java.util.concurrent.TimeUnit              

String dateStart = "11/03/14 09:29:58";
String dateStop = "11/03/14 09:33:43";

// Custom date format
SimpleDateFormat format = new SimpleDateFormat("yy/MM/dd HH:mm:ss");  

Date d1 = null;
Date d2 = null;
try {
    d1 = format.parse(dateStart);
    d2 = format.parse(dateStop);
} catch (ParseException e) {
    e.printStackTrace();
}    

// Get msec from each, and subtract.
long diff = d2.getTime() - d1.getTime();
long diffSeconds = diff / 1000 % 60;         
long diffMinutes = diff / (1000);         
long diffHours = diff / (60 * 1000);        

System.out.println("Time in seconds: " + diffSeconds + " seconds.");         
System.out.println("Time in minutes: " + diffMinutes + " minutes.");         
System.out.println("Time in hours: " + diffHours + " hours."); 

//You can also try this function.
//long seconds = TimeUnit.MILLISECONDS.toSeconds(diff);
//long minutes = TimeUnit.MILLISECONDS.toMinutes(diff);

執行後輸出格式如下
 

Time in seconds: 45 seconds.
Time in minutes: 3 minutes.
Time in hours: 0 hours.