[sajeev_k]

If we are using JNDI data source

is it mandatory to add about this in web.xml

please give an example with source

[t_mohan]

Yes, if u want to get a database connection using JNDI u need to define it in the web.xml.
This is how u have to do

--resource-ref--
description--DB Connection --/description--
--res-ref-name--jdbc/somename --/res-ref-name--
--res-type--javax.sql.DataSource--/res-type--
--res-auth--Container --/res-auth--
--/resource-ref--

And also a context.xml in ur Web application META-INF folder

--Context path="/Webapp1"--
--Resource name="jdbc/somename" auth="Container" type="javax.sql.DataSource" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/urdbname" username="root" password="XXXX" maxActive="100" maxIdle="10" maxWait="10000"/--
--/Context--

This is how u have to define it

And after that write a DB connection class which creates a Connection Pool using this JNDI
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class ConnectionPool {
private static DataSource ds = null;
private ConnectionPool() {}
static {
try {
Context ctx = new InitialContext();
ds = (DataSource) ctx.lookup("java:comp/env/jdbc/somename");
} catch (NamingException ne) {
} catch (Exception e) {
}
}
public static Connection getConnection() {
Connection conn = null;
try {
conn = ds.getConnection();
} catch (SQLException se) {
} catch (Exception e) { }
return conn;
}
}

and in ur some dao class use this

conn = ConnectionPool.getConnection();
stmt = conn.createStatement();

Please use XML opening and closing tags in ur web.xml and context.xml instead of --