Displaying all the months in the year

I have created a calendar in jsp. when the user enters the year, it should display all the 12 months, but am getting a single month 12 times.. please verify the code and help..

<%@page import="java.util.*,java.text.*" %>
 
<html> 
<head>
<title>Print a month page.</title>
<meta name="version"
</head>
<body bgcolor="white">
 
<%
 
boolean yyok = false;
int yy = 0, mm = 0;
String yyString = request.getParameter("year");
if (yyString != null && yyString.length(  ) > 0)
 {
try {
yy = Integer.parseInt(yyString);
yyok = true;
} 
catch (NumberFormatException e) 
{
out.println("Year " + yyString + " invalid");
}
}
Calendar c = Calendar.getInstance(  );
if (!yyok)
yy = c.get(Calendar.YEAR);
                  mm = c.get(Calendar.MONTH);
    
                              for (int i=0; i<months.length; i++)
{
mm = i;
break;
}
 %>
 
<form method=post action="CalendarPage.jsp">
Enter Year : 
<input type="text" size="5" name="year" value=" <%= yy %>"></input>
<input type=submit value="Display">
</form>
<%!
String[] months = 
{
"January", "February", "March", "April",
"May", "June", "July", "August",
"September", "October", "November", "December"
};
 
int dom[] = {
31, 28, 31, 30,
31, 30, 31, 31, 
30, 31, 30, 31
};
%>
 
<%
 
int leadGap = 0;
%>
 
<table border=1>
<tr>
<th colspan=7>
<%= months[mm] %>  
<%= yy %>
</tr>
 
<% 
GregorianCalendar calendar = new GregorianCalendar(yy, mm, 1);
for(int j=1;j<=12;j++)
{
 %>
 
<tr><td>Sunday<td>Monday<td>Tuesday<td>Wednesday<td>Thursday<td>Friday<td>Saturday</tr>
 
<%

leadGap = calendar.get(Calendar.DAY_OF_WEEK)-1;
 
int daysInMonth = dom[mm];
if (calendar.isLeapYear(calendar.get(Calendar.YEAR)) && mm == 1)
++daysInMonth;
 
out.print("<tr>");
                                    out.println(" ");
for (int i = 0; i < leadGap; i++) 
{
out.print("<td> ");
}

for (int i = 1; i <= daysInMonth; i++) 
{
 out.print("<td>");
out.print(i);
out.print("</td>");
 
   if ((leadGap + i) % 7 == 0)
 {
     out.println("</tr>");
     out.print("<tr>");
}
}
}
%>
</tr>
</table>
</html>

Hi Venkatesh,
One question:
is there a need to put so much java code in the jsp?

i would suggest it is better to do the processing in a java class(servlet) and use the jsp for only view purpose.

cheers
thanks
vinny m

I was asked to create a calendar in JSP,rather than using seperate java page.. Please help with my query of displaying all the months..

Hey Venkatesh,
i would still suggest that it is not a good practice for having so much java code in jsp.
However also see the following points in ur code:
which is why it is printing only a single month:
1.what is the need for this loop

2.
You are creating only one instance of calendar and then using the same in the for loop

check this out:i have made some major changes to your code and this will work:

<%@page import="java.util.*,java.text.*" %> <html> <head>
<title>Print a month page.</title>
<meta name="version"</head><body bgcolor="white"> <%
boolean yyok = false;
int yy = 0, mm = 0;
String yyString = request.getParameter("year");
if (yyString != null && yyString.length(  ) > 0)
 {
try {
yy = Integer.parseInt(yyString);
yyok = true;
} 
catch (NumberFormatException e) 
{
out.println("Year " + yyString + " invalid");
}
}
Calendar c = Calendar.getInstance(  );
if (!yyok)
yy = c.get(Calendar.YEAR);                  
mm = c.get(Calendar.MONTH);
out.println("YY=="+yy+",MM=="+mm);
 %> 
 
<form method=post action="CalendarPage.jsp">Enter Year : 
<input type="text" size="5" name="year" value=" <%= yy %>"></input>
<input type=submit value="Display"></form><%!
String[] months = 
{
"January", "February", "March", "April",
"May", "June", "July", "August",
"September", "October", "November", "December"
}; 
 
int dom[] = {
31, 28, 31, 30,
31, 30, 31, 31, 
30, 31, 30, 31
};%> 
<% 
int leadGap = 0;
%> 
<table border=1>
<%
for(int j=0;j<12;j++){ 
 GregorianCalendar calendar = new GregorianCalendar(yy, j, 1);
%> 
<tr><th colspan=7><%= months[j] %> <%= yy %></tr>
<tr><td>Sunday<td>Monday<td>Tuesday<td>Wednesday<td>Thursday<td>Friday<td>Saturday</tr> 
<%
leadGap = calendar.get(Calendar.DAY_OF_WEEK)-1; 
int daysInMonth = dom[j];
if (calendar.isLeapYear(calendar.get(Calendar.YEAR)) && j == 1)
++daysInMonth; 
out.print("<tr>");                                    out.println(" ");
for (int i = 0; i < leadGap; i++) 
{
out.print("<td> ");
} 
for (int i = 1; i <= daysInMonth; i++) 
{ 
out.print("<td>");
out.print(i);
out.print("</td>"); 
   if ((leadGap + i) % 7 == 0)
 {
     out.println("</tr>");
     out.print("<tr>");
}
}}%>
</tr></table></html>

hth,
cheers
vinny m

Hey
further improvements to your code:

<%@page import="java.util.*,java.text.*" %> <html> <head>
<title>Print a month page.</title>
<meta name="version"</head><body bgcolor="white"> <%
boolean yyok = false;
int yy = 0, mm = 0;
String yyString = request.getParameter("year");
if (yyString != null && yyString.length(  ) > 0)
 {
try {
yy = Integer.parseInt(yyString);
yyok = true;
} 
catch (NumberFormatException e) 
{
out.println("Year " + yyString + " invalid");
}
}
Calendar c = Calendar.getInstance(  );
if (!yyok)
yy = c.get(Calendar.YEAR);                  
mm = c.get(Calendar.MONTH);
out.println("YY=="+yy+",MM=="+mm);
 %> 
 
<form method=post action="CalendarPage.jsp">Enter Year : 
<input type="text" size="5" name="year" value=[B]"<%= yy %>"[/B]></input>
<input type=submit value="Display"></form><%!
String[] months = 
{
"January", "February", "March", "April",
"May", "June", "July", "August",
"September", "October", "November", "December"
}; 
 
int dom[] = {
31, 28, 31, 30,
31, 30, 31, 31, 
30, 31, 30, 31
};%> 
<% 
int leadGap = 0;
%> 
<table border=1>
<%
[B]GregorianCalendar calendar =null;[/B]
for(int j=0;j<12;j++){ 
[B] calendar = new GregorianCalendar(yy, j, 1);[/B]
%> 
<tr><th colspan=7><%= months[j] %> <%= yy %></tr>
<tr><td>Sunday<td>Monday<td>Tuesday<td>Wednesday<td>Thursday<td>Friday<td>Saturday</tr> 
<%
leadGap = calendar.get(Calendar.DAY_OF_WEEK)-1; 
int daysInMonth = dom[j];
if (calendar.isLeapYear(calendar.get(Calendar.YEAR)) && j == 1)
++daysInMonth; 
out.print("<tr>");                                    out.println(" ");
for (int i = 0; i < leadGap; i++) 
{
out.print("<td> ");
} 
for (int i = 1; i <= daysInMonth; i++) 
{ 
out.print("<td>");
out.print(i);
out.print("</td>"); 
   if ((leadGap + i) % 7 == 0)
 {
     out.println("</tr>");
     out.print("<tr>");
}
}}%>
</tr></table></html>

this will work properly.
cheers
vinny m

[ February 17, 2006: Message edited by: Vinny Menon ]
[ February 17, 2006: Message edited by: Vinny Menon ]

can u help me use buttons in the code, instead of the plain numbers being shown..

where should i insert this button in the calendar code? when i tried using, am getting the buttons as well as the plain numbers.

I also need to display the calendar in horizontal manner, rather than in the vertical manner?

please help.

Hey guys, you don't need to define the months of the year or the days in a month yourselves -- The Calendar object will do it for you

. In addition, <td> tags need to be terminated by </td> tags!

I've fixed both these things in my simplification of CalendarPage.jsp:

<%@page import="java.util.*, java.text.*" %> 
 
<html> 
<head>
<title>Print a month page.</title>
</head><body bgcolor="white"> <%
 
Calendar calendar = Calendar.getInstance( );
int yy = calendar.get(Calendar.YEAR);
 
String yyString = request.getParameter("year");
if (yyString != null && yyString.length( ) > 0)
{
try {
yy = Integer.parseInt(yyString);
} 
catch (NumberFormatException e) 
{
out.println("Year " + yyString + " invalid");
}
}
out.println("YY=="+yy);
%> 
 
<form method="post" action="CalendarPage.jsp">
Enter Year : <input type="text" size="5" name="year" value="<%= yy %>">
<input type=submit value="Display"></form>
 
<table border=1>
<%
SimpleDateFormat month = new SimpleDateFormat("MMMM yyyy");
for(int j=0;j<12;j++)
{ 
calendar = new GregorianCalendar(yy, j, 1); 
 
%> 
<tr><th colspan=7><%= month.format(calendar.getTime()) %></th></tr>
<tr><td>Sunday</td><td>Monday</td><td>Tuesday</td><td>Wednesday</td><td>Thursday</td><td>Friday</td><td>Saturday</td></tr>
<tr>
<%
 
int leadGap = calendar.get(Calendar.DAY_OF_WEEK)-1; 
int daysInMonth = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);

for (int i = 0; i < leadGap; i++) 
{
out.print("<td> </td>");
} 
for (int i = 1; i <= daysInMonth; i++) 
{ 
out.print("<td>");
out.print(i);
out.print("</td>"); 
if ((leadGap + i) % 7 == 0)
{
out.println("</tr><tr>");
}
}
 
out.println("</tr>");
}
%>
</table></html>

Enjoy

[ February 20, 2006: Message edited by: Jon Emerson ]

I need to display the months in horizontal way, not vertically