日期问题1、获取服务器端当前日期：
代码:
<%@ page import="java.util.Date"%><% Date myDate = new Date();%>
2、获取当前年、月、日：
代码:
<%@ page import="java.util.Date"%><% Date myDate = new Date(); int thisYear = myDate.getYear() + 1900;//thisYear = 2003 int thisMonth = myDate.getMonth() + 1;//thisMonth = 5 int thisDate = myDate.getDate();//thisDate = 30%>
3、按本地时区输出当前日期
代码:
<%@ page import="java.util.Date"%><% Date myDate = new Date(); out.println(myDate.toLocaleString());%>
输出结果为：2003-5-30
4、获取数据库中字段名为”publish_time“、类型为Datetime的值
代码:
<%@ page import="java.util.Date"%><% ...连接数据库... ResultSet rs = ... Date sDate = rs.getDate("publish_time");%>[code]
5、按照指定格式打印日期[code]<%@ page import="java.util.Date"%><%@ page import="java.text.DateFormat"%><% Date dNow = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("E yyyy.MM.dd 'at' hh:mm:ss a zzz"); out.println("It is " + formatter.format(dNow));%>
输出的结果为：It is 星期五 2003.05.30 at 11:30:46 上午 CST (更为详尽的格式符号请参看SimpleDateFormat类)
6、将字符串转换为日期
代码:
<%@ page import="java.util.Date"%><%@ page import="java.text.DateFormat"%><% String input = "1222-11-11"; SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); Date t = null; try{ t = formatter.parse(input); out.println(t); }catch(ParseException e){ out.println("unparseable using " + formatter); }%>
输出结果为：Fri Nov 11 00:00:00 CST 1222
7、计算日期之间的间隔
代码:
<%@ page import="java.util.Date"%><%@ page import="java.text.DateFormat"%><% String input = "2003-05-01"; SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); Date d1 = null; try{ d1 = formatter.parse(input); }catch(ParseException e){ out.println("unparseable using " + formatter); } Date d2 = new Date(); long diff = d2.getTime() - d1.getTime(); out.println("Difference is " + (diff/(1000*60*60*24)) + " days.");%>
输出结果为：Difference is 29 days.
8、日期的加减运算方法：用Calendar类的add()方法
代码:
<%@ page import="java.util.*"%><%@ page import="java.text.*"%><% Calendar now = Calendar.getInstance(); SimpleDateFormat formatter = new SimpleDateFormat("E yyyy.MM.dd 'at' hh:mm:ss a zzz"); out.println("It is now " + formatter.format(now.getTime())); now.add(Calendar.DAY_OF_YEAR,-(365*2)); out.println("<br>"); out.println("Two years ago was " + formatter.format(now.getTime()));%>
输出结果为：It is now 星期五 2003.05.30 at 01:45:32 下午 CST Two years ago was 星期三 2001.05.30 at 01:45:32 下午 CST
9、比较日期方法：用equals()、before()、after()方法
复制内容到剪贴板
代码:
<%@ page import="java.util.*"%><%@ page import="java.text.*"%><% DateFormat df = new SimpleDateFormat("yyy-MM-dd"); Date d1 = df.parse("2000-01-01"); Date d2 = df.parse("1999-12-31"); String relation = null; if(d1.equals(d2)) relation = "the same date as"; else if(d1.before(d2)) relation = "before"; else relation = "after"; out.println(d1 +" is " + relation + ' ' + d2);%>
输出结果为：Sat Jan 01 00:00:00 CST 2000 is after Fri Dec 31 00:00:00 CST 1999
10、记录一件事所花费的时间方法：调用两次System.getTimeMillis()方法，求差值
代码:
<%@ page import="java.text.*"%><% long t0,t1; t0 = System.currentTimeMillis(); out.println("Cyc starts at " + t0); int k = 0; for(int i =0;i<100000;i++){ k += i; } t1 = System.currentTimeMillis(); out.println("<br>"); out.println("Cyc ends at " + t1); out.println("<br>"); out.println("This run took " + (t1-t0) + "ms.");%>
输出结果为：Cyc starts at 1054275312432 Cyc ends at 1054275312442 This run took 10ms. 其它：如何格式化小数
代码:
<%@ page import="java.text.*"%><% DecimalFormat df = new DecimalFormat(",###.00"); double aNumber = 33665448856.6568975; String result = df.format(aNumber); out.println(result);%>
输出结果为：33,665,448,856.66
原帖地址：http://bbs.blueidea.com/viewthread.php?tid=989464
