designing dynamic combo

**creative1** · May 29 '08, 06:26 PM

I wrote a servlet and want to call it to display compy names but I am not getting desired result. I get no errors. if you can just tell me if i m going right.... How should I call servlet?

Code:

<td><select name="clientName"
           
            		<option >../servlet/admin.ShowCompanyNames</option>
 </td>

**creative1** · May 30 '08, 06:45 PM

I am not sure why no one is helping me out. I don't thing populating a combobox at run time would be a problem for experts. In my case, I am a beginner and don't know right method to do this. I am going to post my code so you guys may know what I have in my hand:
I have
connection setup
servlet for querying
JSP for display record
Bean for the Client Information.

Here is my code

For connecting to databse; working fine

Code:

package admin;
import java.sql.*;


//	http://www.javaservice.net/%7Ejava/bbs/read.cgi?b=javatip&c=r_p&m=devtip&n=1014323889&s=t
public class DBPool {
	private static boolean connect = false;
	private static Connection[] cons = null;
	private static int maxCons = 10;
	//private static Boolean[] consStatus = new Boolean[maxCons];
	private static int conID = -1;
	private static final String dbURL = "jdbc:mysql://localhost:3306/virsarmedia";
	private static final String user = "root";
	private static final String password = ""; 
	
	// This DB Pool needs to be re-written so that uses Vector(or Hashtable)
	// not to share one Connection for many Statements
	
	
	
	static{
		try
		{
			System.out.print("Loading MySQL Driver ... ");
			Class.forName("org.gjt.mm.mysql.Driver");
			System.out.println("OK");
		}catch(ClassNotFoundException e){System.out.println(e.getMessage());}
	}
	
	// create Connection
	public static final synchronized Connection createConn(){
		try{
			return DriverManager.getConnection(dbURL,user,password);
		} catch (SQLException e){
			e.printStackTrace();
			return null;
		}
	}
	
	// get db pool manager
	public static final synchronized Connection getConnMgr(){
		// create connections when it's called at the first 
		if(!connect){
			cons = new Connection[maxCons];
			for(int i=0; i<maxCons; i++){
				cons[i] = createConn();
				if(cons[i] == null) return null;
			}
			connect = true;
		}
		
		// round robin returning Connection
		conID++;
		if(conID <= maxCons) conID = 0;
		try{
			if(cons[conID].isClosed()) cons[conID] = createConn();
		} catch(SQLException se){
			System.out.println(se.getMessage());
			cons[conID] = createConn();
		}
		return cons[conID];
	}

	

	
	
	
	// destory all connections
	public static final void destory(){
		connect = false;
		for(int i=0; i<maxCons; i++){
			if(cons[i] != null){
				try{
					cons[i].close();
				} catch(SQLException se){
					cons[i] = null;
				}
			}
		}
		cons = null;
	}
	
	// get numberOfRows
	public static final int getRows(ResultSet rs){
		int numberOfRows = 0;
		try{
			rs.last();
			numberOfRows = rs.getRow();
			rs.beforeFirst();
		} catch(SQLException se){
			se.printStackTrace();
		}
		return numberOfRows;
	}
	
}

Servlet to retrieve clientNames

Code:

package data;
 
import admin.*;
import business.*;
import java.sql.ResultSet;
import java.sql.*;
import java.util.Vector;
public class ClientDB {
	final static String TBL_USER = "client";
public static int readClientID(Connection connection, Client client) throws SQLException{
        //This method will return 0 if ClientID isn't found.
        String query = "SELECT ClientID FROM Client " +
                       "WHERE ClientID = '" + client.getClientID() + "'";
        Statement statement = connection.createStatement();
        ResultSet record = statement.executeQuery(query);
        record.next();
        int clientID = record.getInt("ClientID");
        record.close();
        statement.close();
        return clientID;
    }
}

Finally JSP file where I want to setup combobox;

Code:

<!doctype html public "-//W3C//DTD HTML 4.0 Transitional//EN//">
<html>
<link href="../virsar.css" rel="stylesheet" type="text/css" />
<head>
 <title>Virsar Media Administation Menu</title>
</head>
 
<body>
 
<table cellspacing=0 cellpadding=0>
	<td><img src="../images/title.jpg"></td>
</table>
 
 
<table cellspacing=0 cellpadding=0 width=800>
	<td width=20>
 
 
<!-- <br><br><br><br><br><br><br><br><br><br> -->
	</td>
	<!-- <td width=1 bgcolor=black></td> -->
	<td>
<h1>Subscriptions Processing Menu!</h1>
 
  
 
<%-- Following code can be used to Add the record on the front end--%>
 
<script language="JavaScript">
 
function validate(form) {
    if (form.paymentID.value=="") {
        alert("Please fill in PaymentID");
        form.paymentName.focus();
    }
    else if (form.clientID.value=="") {
        alert("Please fill in ClientID");
        form.clientID.focus();
    }
    else if (form.paymentType.value=="") {
        alert("Please fill in Payment Type");
        form.paymentType.focus();
    }
    
 
    else {
        form.submit();
    }
}
</script>
 
 
  
<table cellpadding="5" border=1>
 
  <tr valign="bottom">
    <th>Subscription ID</th>
    <th>Client ID</th>
    <th>Client Name</th>
    <th>Subscription Type</th>
    <th>Amount</th>
    <th>Subscription Start Date</th>
    <th>Subscription Expiry Date</th>
    <th>Description</th>
    <th>State</th>
    
         
       <th>Update Subscription</th>
          <th>Delete Subscription</th>
  </tr>
 
  
<%@ page import="business.*" %>
<% java.util.Vector payments = (java.util.Vector)session.getAttribute("payments");
 
if(payments != null){
 
    for (int i =0; i<payments.size(); i++){
    
        Payment payment = (Payment)payments.get(i);
	if(payment instanceof Payment){
        %>
        <tr valign="top">
            <td><p><%= payment.getPaymentID() %></td>
            <td><p><%= payment.getClientID() %></td>
            <td><p><%= payment.getClientName() %></td>
            <td><p><%= payment.getPaymentType() %></td>
            <td><p><%= payment.getPaymentAmount() %></td>
            <td><p><%= payment.getPaymentStartDate() %></td>
            <td><p><%= payment.getPaymentExpiryDate() %></td>
            <td><p><%= payment.getPaymentDescription() %></td>
            <td><p><%= payment.getPaymentState() %></td>
            
            
            
                    
            <td><a href="../servlet/admin.ShowPaymentServlet?paymentID=<%=payment.getPaymentID()%>">Update </a></td>
            <td><a href="../servlet/admin.DeletePaymentServlet?paymentID=<%=payment.getPaymentID()%>">Delete </a></td>
             
        </tr>
        <%
	}
    }
}
%>
</table>
 
 
<form action="../servlet/admin.AddPaymentServlet" method="get">
<table cellspacing="5" border="0">
    
    <tr>
        <td align="right">Subscription ID:</td>
        <td><input type="text" name="paymentID" 
                value="">
        </td>
    </tr>
    <tr>
        <td align="right"> Client Name :</td>
        
        <%-- ---------------------------------------- this is where I want to set my combo -------------------- --%>
        
         
            <td>
          
            		<input name="clientName" type = "text" value= "../servlet/admin/ShowCompanyNames.getClientID()"></input>
            		
            </td>
       
   
        <!--  <td><input type="text" name="clientName" 
                value="">
        </td> -->
    </tr>
    <tr>
        <td align="right"> ClientID </td>
        <td><input type="text" name="clientID" 
                value="">
        </td>
    </tr>
    
    <tr>
        <td align="right"> Payment Type :</td>
     <!--   <td><input type="text" name="paymentType" 
                value="">
        </td>
     -->
           <td>
            <INPUT TYPE=RADIO NAME="paymentType" VALUE="Monthly">Montly
			<INPUT TYPE=RADIO NAME="paymentType" VALUE="Yearly">Yearly
			<INPUT TYPE=RADIO NAME="paymentType" VALUE="One Time">One Time
			<INPUT TYPE=RADIO NAME="paymentType" VALUE="Other">Other<br>
 
		    </td>
        
    </tr>
       
       <tr>
        <td align="right"> Payment Amount :</td>
        <td><input type="text" name="paymentAmount" 
                value="">
        </td>
    </tr>
    
       <tr>
        <td align="right"> PaymentStartDate :</td>
        <td><input type="text" name="paymentStartDate" 
                value="">
        </td>
    </tr>
    
       <tr>
        <td align="right"> PaymentExpiryDate :</td>
        <td><input type="text" name="paymentTelephone" 
                value="">
        </td>
    </tr>
    
       <tr>
        <td align="right"> Description :</td>
        <td><input type="text" name="paymentDescription" 
                value="">
        </td>
    </tr>
    
    
       <tr>
        <td align="right"> Status :</td>
        <td><input type="text" name="paymentState" 
                value="">
        </td>
    </tr>
        
    
       <td></td>
        <td><input type="button" value="Add Subscription info." 
                   onClick="validate(this.form)"></td>
    </tr>
</table>
</form>
 
<table>
<tr>
<td>
 
<form action="Cadmin.PaymentsServlet" method="get">
    <input type="submit" value="Refresh List">
</form>
</td><td>
<form action="../Admin/index.html">
    <input type="submit" value="Go Back">
</form>
</td>
</table>
 
 </td>
</table>
 
</html>
 
 /body>
</html>

I can display client payment information. My only concern is to populate combobox. All I need is to know how I do that. either using beans or servlet? and syntax.........
please help me it's urgent..
Thanks

**BigDaddyLH** · May 30 '08, 08:38 PM

You may have more luck getting a response on a forum dedicated to JSP, like:

http://forum.java.sun.com/forum.jspa?forumID=45

**creative1** · Jun 1 '08, 04:22 AM

thanks,
I don;t see any help around. I am still working ion it. Will post if I got any success.

**creative1** · Jun 2 '08, 09:04 PM

I got combo working values are obtained successfully. Now I want to know how I can bound a text field to hold the ID of the ClientName selected. Any idea?
Can I use LTRIM? if I store client name like this 1 - ABC corp. where 1 is client ID in combobox. Any ideas?
Regards

designing dynamic combo

designing dynamic combo

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