How to retrieve data by using combo box value in jsp?

How to retrieve data by using combo box value in jsp?

Hi Friends,

When i click combobox value in jsp form page, it will diplay related value.... I am using only this page.. not get value from another page...
For Example, in Student.jsp... when i click student id in combo box, the related student name will be display. I can stored all student id stored in combo box from database.. by using select*from studentinformation;

But when i click combobox the related student name did not display...

On friend gave the follwing link

http://www.roseindia.net/jsp/comboSelect.shtml ull pointer exception

if i am trying null pointer exception will be occured.. I need immediately respose from u......




View Answers

February 24, 2010 at 3:34 PM

Hi i try the URL given above
http://www.roseindia.net/jsp/comboSelect.shtml
and i run that project with my settings
it works


I'm using enterprisedb ,and glassfish v2 and netbeans
change these settings to your settings and run app.

My sample table script is below.
CREATE TABLE "user"
(
"name" character varying(100),
eid character varying
)

--------code ------------------------------getuser.jsp----------------------------------
<%@ page import="java.sql.*" %>
<%
String emp_id = request.getParameter("emp_id").toString();
String data ="";

Connection conn = null;
String url = "jdbc:edb://127.0.0.1:5444/";;
String dbName = "nb";
String driver = "com.edb.Driver";
String userName = "enterprisedb";
String password = "OLIMPUS";

int sumcount=0;
Statement st;
try {
Class.forName(driver).newInstance();

conn = DriverManager.getConnection(url+dbName,userName,password);
String query = "select name,eid from public.user where name='"+emp_id+"'" ;

st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
while(rs.next())
{
data = ":" + rs.getString(1)+" " + rs.getString(2) ;
}


out.println(data);
}
catch (Exception e) {
e.printStackTrace();
}
%>

---------------------------combobox.jsp------------------------------------
------------
<%@ page import="java.sql.*" %>
<html>
<head>
<style>
A:hover {text-decoration: none;

border: 0px;
font-size:14pt;
color: #2d2b2b; }
</style>

<link rel="stylesheet" type="text/css" href="datepicker.css"/>


<script type="text/javascript">
function showEmp(emp_value)
{
if(document.getElementById("emp_id").value!="-1")
{
xmlHttp=GetXmlHttpObject()
if (xmlHttp==null)
{
alert ("Browser does not support HTTP Request")
return
}
var url="getuser.jsp"
url=url+"?emp_id="+emp_value

xmlHttp.onreadystatechange=stateChanged
xmlHttp.open("GET",url,true)
xmlHttp.send(null)

}
else
{
alert("Please Select Employee Id");
}
}

function stateChanged()
{
document.getElementById("ename").value ="";
document.getElementById("emp_id").value ="";
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
{

var showdata = xmlHttp.responseText;
var strar = showdata.split(":");

if(strar.length==1)
{
document.getElementById("emp_id").focus();
alert("Please Select Employee Id");
document.getElementById("ename").value =" ";
document.getElementById("emp_id").value =" ";

}
else if(strar.length>1)
{
var strname = strar[1];
document.getElementById("emp_id").value= strar[2];
document.getElementById("ename").value= strar[1];
}

}
}

function GetXmlHttpObject()
{
var xmlHttp=null;
try
{
// Firefox, Opera 8.0+, Safari
xmlHttp=new XMLHttpRequest();
}
catch (e)
{
//Internet Explorer
try
{
xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e)
{
xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
}
}
return xmlHttp;
}
</script>

</head>
<body>
<form name="employee">
<br><br>
<table border="0" width="400px" align="center" bgcolor="#CDFFFF">
<div id="mydiv"></div>
<tr><td><b>Select Employee Id</b></td><td>
<select name="semp_id" onchange="showEmp(this.value);">
<option value="-1">Select</option>
<%



Connection conn = null;
String url = "jdbc:edb://127.0.0.1:5444/";;
String dbName = "nb";
String driver = "com.edb.Driver";
String userName = "enterprisedb";
String password = "OLIMPUS";

int sumcount=0;
Statement st;
try {
Class.forName(driver).newInstance();

conn = DriverManager.getConnection(url+dbName,userName,password);
String query = "select name from public.user";

st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
%>

<%
while(rs.next())
{
%>

<option value="<%=rs.getString(1)%>"><%=rs.getString(1)%></option>

<%
}
%>

<%

}
catch (Exception e) {
e.printStackTrace();
}

%>

</select>
</td></tr>


<tr><td ><b>Employee Id:</b></td><td><input type="text" name="emp_id" id="emp_id" value=""></td></tr>
<tr><td><b>Employee Name:</b></td><td><input type="text" name="emp_name" id="ename" value=""></td></tr>

</table>
</form>

<table border="0" width="100%" align="center">


<br>
<br>


</table>
</body>
</html>

Hope this helpful.
Best Regards.









Related Tutorials/Questions & Answers:
How to retrieve data by using combo box value in jsp? - JSP-Servlet
How to retrieve data by using combo box value in jsp? - JSP-Servlet
Advertisements
How to retrieve data using combo box value in jsp? - JSP-Servlet
How to retrieve data by using combo box value in jsp? - JSP-Servlet
How to retrieve data from database by using combo box value in jsp? - JSP-Servlet
How to retreive data by using combo box value - JSP-Servlet
retrieve the data to text fields from database on clicking the value of combo box
How to retreive data by using combo box value - JSP-Servlet
Populate a combo box using data from a database
how to retrieve data from database using combobox value without using request.getParameter in jsp - JSP-Servlet
how to get combo box value - JSP-Servlet
how i conditional access the data from database using combo box. - JSP-Servlet
Acees data from database using combo box - JSP-Servlet
Retrieving data from data base using jsp combo box
How to pass the value of Selected Value of combo box into sql ??
combo box value
combo box value
how can retrive value from combo box in servlet?
How to Retrieve Data from Facebook Using PHP
How to Retrieve Data from Facebook Using PHP
Combo box value Error - WebSevices
How to create textbox on combo value selection using javacsript in jsp?
how to retrieve data into combo from database in java applet?
Retrieving Data from Database to fill Combo Box
loading value into combo box by selecting value from other combo box - JSP-Servlet
base the value of first combo box, how i display the second combox - JSP-Servlet
Re: base the value of first combo box, how i display the second combox - JSP-Servlet
Re: base the value of first combo box, how i display the second combox - JSP-Servlet
How to show autocomplete textbox values on combo box option selection using database?
How to Retrieve Data from the database and write into excel file using Java
Store combo box value - Development process
How to create Combo Box in SWT
how to create a combo box in html
JSP1
How to get data from DB in to Text box by using Jsp & Ajax
populate Combo Box dynamically
How to "Get data froom MySQL DB on giving a value in a tex-box in a JSP file."
retrieve value from db in text box + calendar implementation.
Retrieve data using Criteria api
how to retrieve data from multiple tables in jsp using javabeans
how to retrieve data from multiple tables in jsp using javabeans
how to retrieve data from multiple tables in jsp using javabeans
how to get selected name from combo box
how to get selected name from combo box
how to get selected name from combo box
how to get selected name from combo box
how to get selected name from combo box
how to retrieve data from database
how to retrieve a checkbox value(retrieve from DB)
Dynamic loading of Combo box list using servlet - JSP-Servlet

Ads