對Java語言中的日期處理大全

<script type="text/javascript"> google_ad_client = "pub-8800625213955058"; /* 336x280, 創建於 07-11-21 */ google_ad_slot = "0989131976"; google_ad_width = 336; google_ad_height = 280; // </script> <script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> 1、獲取服務器端當前日期： &lt%@ page import="java.util.Date"%&gt &lt% Date myDate = new Date(); %&gt 2、獲取當前年、月、日： &lt%@ page import="java.util.Date"%&gt &lt% Date myDate = new Date(); int thisYear = myDate.getYear() 1900;//thisYear = 2003 int thisMonth = myDate.getMonth() 1;//thisMonth = 5 int thisDate = myDate.getDate();//thisDate = 30 %&gt 3、按本地時區輸出當前日期 &lt%@ page import="java.util.Date"%&gt &lt% Date myDate = new Date(); out.println(myDate.toLocaleString()); %&gt 輸出結果爲： 2003-5-30 4、獲取數據庫中字段名爲"publish_time"、類型爲Datetime的值 &lt%@ page import="java.util.Date"%&gt &lt% ...連接數據庫... ResultSet rs = ... Date sDate = rs.getDate("publish_time"); %&gt 5、按照指定格式打印日期 &lt%@ page import="java.util.Date"%&gt &lt%@ page import="java.text.DateFormat"%&gt &lt% 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)); %&gt 輸出的結果爲： It is 星期五 2003.05.30 at 11:30:46 上午 CST (更爲詳盡的格式符號請參看SimpleDateFormat類) 6、將字符串轉換爲日期 &lt%@ page import="java.util.Date"%&gt &lt%@ page import="java.text.DateFormat"%&gt &lt% 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); } %&gt 輸出結果爲： Fri Nov 11 00:00:00 CST 1222 7、日期的加減運算 方法：用Calendar類的add()方法 &lt%@ page import="java.util.*"%&gt &lt%@ page import="java.text.*"%&gt &lt% 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("&ltbr&gt"); out.println("Two years ago was " formatter.format(now.getTime())); %&gt 輸出結果爲： 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 8、比較日期 方法：用equals()、before()、after()方法 &lt%@ page import="java.util.*"%&gt &lt%@ page import="java.text.*"%&gt &lt% 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); %&gt 輸出結果爲： Sat Jan 01 00:00:00 CST 2000 is after Fri Dec 31 00:00:00 CST 1999 9、記錄一件事所花費的時間 方法：調用兩次System.getTimeMillis()方法，求差值 &lt%@ page import="java.text.*"%&gt &lt% long t0,t1; t0 = System.currentTimeMillis(); out.println("Cyc starts at " t0); int k = 0; for(int i =0;i&lt100000;i ) t1 = System.currentTimeMillis(); out.println("&ltbr&gt"); out.println("Cyc ends at " t1); out.println("&ltbr&gt"); out.println("This run took " (t1-t0) "ms."); %&gt 輸出結果爲： Cyc starts at 1054275312432 Cyc ends at 1054275312442 This run took 10ms. 10：如何格式化小數 &lt%@ page import="java.text.*"%&gt &lt% DecimalFormat df = new DecimalFormat(",###.00"); double aNumber = 33665448856.6568975; String result = df.format(aNumber); out.println(result); %&gt 輸出結果爲： 33,665,448,856.66