calling a bean object from a servlet into a plain java class

How to access a bean object from a servlet into a plain java class.

The same way as any other java class. A bean is, after all, just a Java class like any other. What specific difficulty are you having?

I put database details such as sid, user, pswd etc as context param. I called the same in a servlet using listener and put them in a bean object. Now i want to call the object in a pojo to make connection

You don't call objects. you call methods. But you still haven't expressed what your issue is.

Are you having trouble passing the bean to another class? Trouble creating the bean in the first place? What's the actual problem?

Thanks Bibeault for your instant response. I will give you the details what I actually want to do:-

My web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <context-param>
        <description>orcl sid</description>
        <param-name>orclsid</param-name>
        <param-value>orcl</param-value>
    </context-param>
  
    <context-param>
        <description>server ip</description>
        <param-name>orclserver</param-name>
        <param-value>localhost</param-value>
    </context-param>
    <context-param>
        <description>user id</description>
        <param-name>orcluser</param-name>
        <param-value>abc</param-value>
    </context-param>
    <context-param>
        <description>password</description>
        <param-name>orclpswd</param-name>
        <param-value>xyz</param-value>
    </context-param>
    <context-param>
        <description>orcl port</description>
        <param-name>orclport</param-name>
        <param-value>1521</param-value>
    </context-param>
    
    <listener>
        <description>ServletContextListener</description>
        <listener-class>mmhr.listener.DbContextListener</listener-class>
    </listener>

---------------
My DBContextListener Class:-
--------------

package mmhr.listener;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

/**
 * Web application lifecycle listener.
 * @author Administrator
 */
public class DbContextListener implements ServletContextListener {

public void contextInitialized(ServletContextEvent sce) {
        //throw new UnsupportedOperationException("Not supported yet.");

ServletContext sc = sce.getServletContext();
        String orclSid = sc.getInitParameter("orclsid");
        String orclServer = sc.getInitParameter("orclserver");
        String orclUser = sc.getInitParameter("orcluser");
        String orclPswd = sc.getInitParameter("orclpswd");
        String orclPort = sc.getInitParameter("orclport");
        DB db = new DB();
        db.setOrclSid(orclSid);
        db.setOrclServer(orclServer);
        db.setOrclUser(orclUser);
        db.setOrclPswd(orclPswd);
        db.setOrclport(orclPort);
        
        sc.setAttribute("db", db);

}

public void contextDestroyed(ServletContextEvent sce) {
        ServletContext sc=sce.getServletContext();
        sc.removeAttribute("db");

}
}

=====
DB Bean class
-------------

package mmhr.listener;

public class DB {
private String orclSid=null;
    private String orclServer = null;
    private String orclUser = null;
    private String orclPswd = null;
    private String orclport=null;

public DB() {
    }

public String getOrclSid() {
        return orclSid;
    }

public void setOrclSid(String orclSid) {
        this.orclSid = orclSid;
    }

public String getOrclServer() {
        return orclServer;
    }

public void setOrclServer(String orclServer) {
        this.orclServer = orclServer;
    }

public String getOrclUser() {
        return orclUser;
    }

public void setOrclUser(String orclUser) {
        this.orclUser = orclUser;
    }

public String getOrclPswd() {
        return orclPswd;
    }

public void setOrclPswd(String orclPswd) {
        this.orclPswd = orclPswd;
    }

public String getOrclport() {
        return orclport;
    }

public void setOrclport(String orclport) {
        this.orclport = orclport;
    }

}

===
====
DBListener where I access the bean object. I tested the out put here which is correct.
-------------------------

package mmhr.listener;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ListenerTester extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //response.setContentType("application/octate-stream");
        // PrintWriter out = response.getWriter();
      /*  try {

out.println("test att by servlet listen<br>");
        DB db=(DB)getServletContext().getAttribute("db");

out.println("<html>");
        out.println("<head>");
        out.println("<title>Servlet ListenerTester</title>");
        out.println("</head>");
        out.println("<body>");
        out.println("<h1>Servlet ListenerTester at " + request.getContextPath () + "</h1>");
        out.println("DB :"+db.getOrclSid());
        out.println("DB :"+db.getOrclServer());
        out.println("DB :"+db.getOrclUser());
        out.println("DB :"+db.getOrclPswd());
        out.println("</body>");
        out.println("</html>");

} finally { 
        out.close();
        }*/

}

@Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
        response.setContentType("application/octet-stream");
        //PrintWriter out = response.getWriter();

}

/** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

/** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}

===========

POJO Class where I want to access the bean object for further processing.
//db will be the object of the DB class.jdbc and odbc i will define here.
------------------------

package mmhr.database;

import java.sql.*;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class Conn {

public static Connection con;
    //public Statement st ;
    public Connection connect;
    public PreparedStatement pstmt = null;
    public Statement stmt = null;
    public ResultSet rs = null;
    public ResultSetMetaData rsmd = null;
    public static String err = null;
    
    
    /** Creates a new instance of Conn */
    public Conn() {
    }

public void makeConn() {

try {
            Class.forName(jdbc);
            connect = DriverManager.getConnection(odbc, db.usr, db.pwd);

} catch (SQLException se) {
            err = err + "/in makeConn/" + (String) se.getMessage();

} catch (Exception e) {
            err = err + "/in makeConn/" + (String) e.getMessage();
            System.out.println("Error Connecting to Oracle  " + e.toString());

}

public void useConn(String query) {

try {

stmt = connect.createStatement();
            rs = null;
            rs = stmt.executeQuery(query);
        } catch (Exception e) {
            err = err + "/in useConn/ " + (String) e.getMessage();
        }

}

public void closeConn() {
        
        Connection connect = null;

try {
            if (connect != null) {
                connect.commit();
                connect.clearWarnings();
                connect.close();
            }
        } catch (SQLException e) {
            err = err + "/in closeConn /" + (String) e.getMessage();
        }

}

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Thank You for your suggestions for using code tags. It is really useful.
Now let me show my problem in details:

My web.xml