import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class DateTest {   public static void main(String[] args) throws ParseException {     Calendar now = Calendar.getInstance();     System.out.println("年: " + now.get(Calendar.YEAR));     System.out.println("月: " + (now.get(Calendar.MONTH) + 1) + "");     System.out.println("日: " + now.get(Calendar.DAY_OF_MONTH));     System.out.println("時: " + now.get(Calendar.HOUR_OF_DAY));     System.out.println("分: " + now.get(Calendar.MINUTE));     System.out.println("秒: " + now.get(Calendar.SECOND));     System.out.println("當前時間毫秒數：" + now.getTimeInMillis());     System.out.println(now.getTime());     Date d = new Date();     System.out.println(d);     SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");     String dateNowStr = sdf.format(d);     System.out.println("格式化后的日期：" + dateNowStr);     String str = "2012-1-13 17:26:33"; //要跟上面sdf定義的格式一樣     Date today = sdf.parse(str);     System.out.println("字符串轉成日期：" + today);   } }