Here is a jsp application that retrieves database records in a table and export the data to excel file. You need POI api to run the given code.

1)data.jsp:

<%@page import="java.sql.*"%>
<form method="post" action="excelFile.jsp">
<table border=1>
<tr><th>Name</th><th>Address</th><th>Contact No</th><th>Email</th></tr>
<%
Class.forName("com.mysql.jdbc.Driver").newInstance();  
 Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");  
Statement st=con.createStatement();
ResultSet rs=st.executeQuery("Select * from employee");
while(rs.next()){
    %>
<tr><td><input type="text" name="name" value="<%=rs.getString("name")%>"></td><td><input type="text" name="address" value="<%=rs.getString("address")%>"></td><td><input type="text" name="contact" value="<%=rs.getString("contactNo")%>"></td><td><input type="text" name="email" value="<%=rs.getString("contactNo")%>"></td></tr>
<%
}
%>
</table>
<input type="submit" value="Export To Excel">
</form>

2)excelFile.jsp:

<%@page import="  java.io.*"%>  
<%@page import="  org.apache.poi.hssf.usermodel.*"%>  
<%
String name[]=request.getParameterValues("name");
String address[]=request.getParameterValues("address");
String contact[]=request.getParameterValues("contact");
String email[]=request.getParameterValues("email");

try{
String filename="c:/data.xls" ;
HSSFWorkbook hwb=new HSSFWorkbook();
HSSFSheet sheet =  hwb.createSheet("sheet");

HSSFRow rowhead=   sheet.createRow((short)0);
rowhead.createCell((short) 0).setCellValue("Name");
rowhead.createCell((short) 1).setCellValue("Address");
rowhead.createCell((short) 2).setCellValue("Contact No");
rowhead.createCell((short) 3).setCellValue("E-mail");
for(int i=0;i<name.length;i++){
    int j=i+1;
HSSFRow row=   sheet.createRow((short)j);
row.createCell((short) 0).setCellValue(name[i]);
row.createCell((short) 1).setCellValue(address[i]);
row.createCell((short) 2).setCellValue(contact[i]);
row.createCell((short) 3).setCellValue(email[i]);
}
FileOutputStream fileOut =  new FileOutputStream(filename);
hwb.write(fileOut);
fileOut.close();
out.println("Your excel file has been generated!");
} catch( Exception ex ) {
    System.out.println(ex);
}
%>

hi thanks dude. here you created a table and exported to excel. but i created grid in extjs and have to export to the excel. please help me for that.. thanks dude.