How to create calendar?

Question

hey guys,
i need help from all of you. recently i was creating an application and this application require an event calendar. My problem is how to i create the event calendar? i have think of using HTML to create that calendar but it is quite cumbosome - need to design 12 image map fro every year and this is very ineffective. how to create that calendar in more effective way? for example, i want that calendar use the time zone in our computer and dynamically change the date. furthermore, if the user click on the highlighted date, it will eventually connect to the database and retrive data.
example to illustrate my problem;
let say this month i have 5 events happen on 12, 24, 25,26, and 27. all this date is highlighted. when users click on the highlighted date, the system will actually connect to database and retrive data. when january of 2004 is arrive, the event calendar can automatically change according to the time zone.
please help me....
best regards and cheers
eric

Answer 1

Eric,
Here is some sample code from one of my apps... it's a little messy. It could be optimized in a few places.
It prints out a month view of a calendar, and I've marked where I put some logic that queries the database and prints out some events if they are scheduled for that particular day of the month.
<%@ page import="java.util.Calendar" %>
<%@ page import="java.util.Date" %>
<%@ page import="java.util.GregorianCalendar" %>
<%@ page import="java.sql.*" %>
<%@ page import="java.util.*" %>
<form name="selectdate">
<%
     Calendar calendar = new GregorianCalendar();
     Date trialTime = new Date();
     calendar.setTime(trialTime);
     Calendar calendar2 = new GregorianCalendar();
     calendar2.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), 1);
     int today = calendar.get(Calendar.DAY_OF_MONTH);
     int currentYear = calendar.get(Calendar.YEAR);
     String Month = "";
     int daynum= 1;
     int column = 1;
     int row = 1;
     int year = 0;
     int month = 0;
     int prev_month = 0;
     int next_month = 0;
     int prev_year = 0;
     int next_year = 0;
     String m = request.getParameter("month");
     if (m==null) {
          month = calendar2.get(Calendar.MONTH);
     } else {
          month = Integer.parseInt(m);
          calendar2.set(calendar2.get(Calendar.YEAR),month,1);
     String y = request.getParameter("year");
     if (y==null) {
          year = calendar2.get(Calendar.YEAR);
     } else {
          year = Integer.parseInt(y);
          calendar2.set(year,calendar2.get(Calendar.MONTH),1);
     if (month - 1 < 0) {
          prev_month = 11;
          prev_year = year - 1;
     } else {
          prev_month = month - 1;
          prev_year = year;
     if (month + 1 > 11) {
          next_month = 0;
          next_year = year + 1;
     } else {
          next_month = month + 1;
          next_year = year;
     int firstDay = calendar2.get(Calendar.DAY_OF_WEEK);
     switch (month) {
          case Calendar.JANUARY:           Month = "January";break;
          case Calendar.FEBRUARY:      Month = "February";break;
          case Calendar.MARCH:           Month = "March";break;
          case Calendar.APRIL:           Month = "April";break;
          case Calendar.MAY:                Month = "May";break;
          case Calendar.JUNE:           Month = "June";break;
          case Calendar.JULY:           Month = "July";break;
          case Calendar.AUGUST:           Month = "August";break;
          case Calendar.SEPTEMBER:      Month = "September";break;
          case Calendar.OCTOBER:           Month = "October";break;
          case Calendar.NOVEMBER:      Month = "November";break;
          case Calendar.DECEMBER:      Month = "December";break;
%>
     <table border="0" cellpadding="0" cellspacing="0" width="95%" align="LEFT">
          <tr>
          <td colspan="4" valign="top">
               <table border="0" cellpadding="0" cellspacing="0" width="100%">
                    <tr>
                         <td colspan="7" align=center>
                         <a href="index.jsp?year=<%= prev_year %>&month=<%= prev_month %>"><<</a>
                         ��
                         <b><%= Month %> <%= year %></b>
                         ��
                         <a href="index.jsp?year=<%= next_year %>&month=<%= next_month %>">>></a>
                         </td>
                    </tr>
                    <tr>
                         <td align=center class="large_calendar_header">Sun</td>
                    <td align=center class="large_calendar_header">Mon</td>
                    <td align=center class="large_calendar_header">Tue</td>
                    <td align=center class="large_calendar_header">Wed</td>
                    <td align=center class="large_calendar_header">Thu</td>
                    <td align=center class="large_calendar_header">Fri</td>
                    <td align=center class="large_calendar_header">Sat</td>
                    </tr>
                    <tr>
<%
     int maxdays = calendar2.getActualMaximum(Calendar.DAY_OF_MONTH);
     String max = String.valueOf(maxdays);
     while (daynum<=maxdays) {
          if (row==1) {
               for (int j=1; j<firstDay; j++) {
%>
                         <td align=center class="large_calendar_blank">�</td>
<%
                    column++;
     while ((column<8)&&(daynum<=maxdays)) {
%>
          <td valign="top" align="left" width="14.28%" height="75" class="large_calendar">
               <font style="font-size: 10px"
<%
               if ((calendar.get(Calendar.MONTH))==(calendar2.get(Calendar.MONTH)) &&
                    (calendar.get(Calendar.YEAR))==(calendar2.get(Calendar.YEAR)) &&
                    (calendar.get(Calendar.DAY_OF_MONTH))==daynum) {
%>
                                   color="#ff0000"
<%
%>
                              ><%= daynum %></font><br>
<%
               String query_date = calendar.get(Calendar.YEAR) + "-" +
                                        (calendar.get(Calendar.MONTH) + 1) + "-" +
                                        daynum;
// You could insert logic here to conditionally display events from a db
%>
                         </td>
<%
               column++;
               daynum++;
          if (column!=8) {
          for (int j=column; j<8; j++) {
%>
                         <td class="large_calendar_blank">�</td>
<%
%>
                    </tr>
<%
     if (daynum<maxdays) {
%>
                    <tr>
<%
column=1;
row++;
%>
</table>
</td>
</tr>
</table>
</form>