在core Java 那本书里,在讲类之前就将了一个打印一个月份中每天是星期几的万年历程序.最近写程序的时候终于要用到了.我花费了半天时间终于弄明白了GregorianCalendar类,并且通过网络抓取oracle数据的时间,然后显示在JSP 网页上.

运行效果如下:

首先要在J2se里面写出万年历程序,作为练习:

1)星期日Calendar.SUNDAY =1 星期日为1,那么星期几就+1为以此类推!

打印月历的程序:

package moonsoft.j2se.testYueli;

import java.util.*;

public class TestYueli

{

public static void main(String [] args)

{ //建立一个GregorianCalendar 对象

GregorianCalendar d=new GregorianCalendar();

//获得系统默认的日期的月份和日期所在的月第几天

int month=d.get(Calendar.MONTH);

int day=d.get(Calendar.DAY_OF_MONTH);

//把d设置为当月第一天

d.set(Calendar.DAY_OF_MONTH, 1);

//获得第一天的是一星期的第几天

int weekday=d.get(Calendar.DAY_OF_WEEK);

System.out.println("SUN MON TUE WED THU FRI SAT");

for(int i=Calendar.SUNDAY; i

System.out.print(" ");

//System.out.print(monthday);

do

{

int days=d.get(Calendar.DAY_OF_MONTH);

if(days<10)

System.out.print(" ");

System.out.print(days);

if(days==day)

System.out.print("*");

else

System.out.print(" ");

if(weekday==Calendar.SATURDAY)

System.out.println();

d.add(Calendar.DAY_OF_MONTH, 1);

weekday=d.get(Calendar.DAY_OF_WEEK);

}while(d.get(Calendar.MONTH)==month);

} }

2)注意GregorianCalendar calendar=new(year, month-1,year);

month-1! 在Calendar 0代表一月!!!

然后再写oracle抓取到JSP 页面的程序:

<%@ page contentType="text/HTML;charset=Big5"%><%@ page import="java.util.*"%><%@ page import="java.sql.*"%><%@ page import="javax.sql.*"%><%@ page import="javax.naming.*"%> <% request.setCharacterEncoding("big5"); String name=(String)session.getAttribute("name"); String queryDate=" select to_char(systimestamp, 'YYYY-MM-DD HH24:MM:SS') from dual "; int day=1; int month=3; int year=2005; Connection conn=null; try{ Context ctx=new InitialContext(); DataSource ds=(DataSource)ctx.lookup("jdbc/asdbCoreDS"); conn=ds.getConnection(); PreparedStatement ps=conn.prepareStatement(queryDate); ResultSet rs=ps.executeQuery(); while(rs.next()){ String date=rs.getString(1); year=Integer.parseInt(date.substring(0,4)); month=Integer.parseInt(date.substring(5,7)); day=Integer.parseInt(date.substring(8,10)); out.println(year+"年"+month+"月"); } } catch(Exception e1){e1.printStackTrace();} finally{conn.close();} %> <% GregorianCalendar d=new GregorianCalendar(year, month-1 , day); int monthDay=d.get(Calendar.DAY_OF_MONTH); int monthNumber=d.get(Calendar.MONTH); d.set(Calendar.DAY_OF_MONTH, 1); int weekDay=d.get(Calendar.DAY_OF_WEEK); for(int i=Calendar.SUNDAY; i<%} do{ int monthDays=d.get(Calendar.DAY_OF_MONTH); %><% if(weekDay==Calendar.SATURDAY) out.println(""); d.add(Calendar.DAY_OF_MONTH, 1); weekDay=d.get(Calendar.DAY_OF_WEEK); }while(d.get(Calendar.MONTH)==monthNumber); %>

SUN	MON	TUE	WED	THU	FRI	SAT
	<%=monthDays%>

其实如果掌握了GregorianCalendar 类,写这个不是很难,呵呵,下一步要做的是要向日历里添加活动信息.

每遇到一个没有写过的技术问题,都觉得很困难,想放弃,可是我不能!我能做的只是坚持,还有培养自己的兴趣,

当你写过这个程序,就觉得,如此而已啊,哈哈......

自己每天都进步一些,这种感觉,真好!