Dynamic loading of Combo box list using servlet

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September 8, 2008 at 2:53 PM

Hi friend

I give theortical descrption read it!

Select a value from drop dwon box, retrive it in a servlet,

By using this value communicate to the data base and the resulst set which you getting passed into your jsp page.

Then iterate resultset in jsp by suing jstl or simply as your wish

Thanks
Rajanikant

September 9, 2008 at 6:23 PM

Hi friend,

<%@ page language="java" import = "java.util.*;"%>
<%
List userList;
int nouser;
int i=1;
List cityList;
int nocity;
int j=1;
%>
<%
userList=(ArrayList)request.getAttribute("useridList");
nouser = userList.size();
%>

<%
cityList=(ArrayList)request.getAttribute("cityList");
nocity=cityList.size();
%>
<html>
<head>
<title>dynamic bombobox in servlet</title>
</head>
<body>
<br><br>
<center>
<table border="1" width="300px" bgcolor="bluelight" cellspacing="0" cellpadding="0">
<tr>
<td width="100%">
<form method="GET" action="/examples/jsp/ComboboxList">
<font color="red"><h3 align="center">Dynamic Combobox List</font></h3>
<table border="1" width="300px" cellspacing="0" cellpadding="0">
<tr>
<td width="50%"><b>User Name:</b></td>
<td width="50%"><select name="userid" value="">
<option value="0">---Select Name---</option>
<%
Iterator userit= userList.iterator();
while(userit.hasNext()){
while(i<=nouser){%>
<option value="<%=i%>"><%=userit.next()%></option>
<%
i++;
}
}
%>
</select>
</td>
</tr>
<tr>
<td width="50%"><b>City:</b></td>
<td width="50%">
<select name="city" value="">
<option value="0">----Select city----</option>
<%
Iterator cityit= cityList.iterator();
while(cityit.hasNext()){
while(j<=nocity){%>
<option value="<%=j%>"><%=cityit.next()%></option>
<%
j++;
}
}
%>

</select>

</td>
</tr>

</table>

</form>
</td>
</tr>
</table>
</center>
</body>

</html>

September 9, 2008 at 6:26 PM

package javacode;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.util.*;
import java.util.ArrayList;

public class ComboboxList extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException{
response.setContentType("text/html");
PrintWriter pw = response.getWriter();
Connection con = null;
String url = "jdbc:mysql://192.168.10.211:3306/";;
String db = "amar";
String driver = "com.mysql.jdbc.Driver";
String userName ="amar";
String password="amar123";
try{
Class.forName(driver);
con = DriverManager.getConnection(url+db,userName,password);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("select * from Combolist");
List ulist = new ArrayList();
List clist = new ArrayList();
while(rs.next()){
request.setAttribute("userid", rs.getString(2));
request.setAttribute("city", rs.getString(3));
pw.println("userid" + " "+"city"+"<br>");
pw.println(rs.getString(2) + " " + rs.getString(3) +"<br>");
ulist.add(rs.getString(2));
clist.add(rs.getString(3));

}
request.setAttribute("useridList", ulist);
request.setAttribute("cityList", clist);
}
catch (Exception e){
pw.println(e);
}
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/jsp/Combobox.jsp");
dispatcher.forward(request, response);
}

}
----------------------------------------------------------
Read for more information with example at

http://www.roseindia.net/servlets/

Thanks

Amardeep

February 14, 2017 at 10:58 AM

Hi,

Also check this tutorial: Populate a combo box using data from a database

Thanks