package com.ob;                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("时: " + 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("当前时间毫秒数：" + 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定义的格式一样                Date today = sdf.parse(str);                System.out.println("字符串转成日期：" + today);            }        }

输出结果：

年: 2012
月: 1
日: 13
时: 17
分: 28
秒: 19
当前时间毫秒数：1326446899902
Fri Jan 13 17:28:19 CST 2012
Fri Jan 13 17:28:19 CST 2012
格式化后的日期：2012-01-13 17:28:19
字符串转成日期：Fri Jan 13 17:26:33 CST 2012