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<weekday; 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.*"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Big5">
<title>社團活動</title>
<style type="text/css">
<!--
.style1 {color: #FFFFFF}
-->
</style>
</head>
<%
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();}
%>
<body>
<table width="100%" border="1" cellspacing="1" cellpadding="1">
<tr bgcolor="#0099FF">
<th scope="col"><span class="style1">SUN</span></th>
<th scope="col"><span class="style1">MON</span></th>
<th scope="col"><span class="style1">TUE</span></th>
<th scope="col"><span class="style1">WED</span></th>
<th scope="col"><span class="style1">THU</span></th>
<th scope="col"><span class="style1">FRI</span></th>
<th scope="col"><span class="style1">SAT</span></th>
</tr> <tr>
<%
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<weekDay; i++)
{%><td height="45"> </td><%}
do{
int monthDays=d.get(Calendar.DAY_OF_MONTH);
%><td height="45"><%=monthDays%></td><%
if(weekDay==Calendar.SATURDAY)
out.println("</tr><tr>");
d.add(Calendar.DAY_OF_MONTH, 1);
weekDay=d.get(Calendar.DAY_OF_WEEK);
}while(d.get(Calendar.MONTH)==monthNumber);
%>
</table>
</body>
</html>
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!
