Wednesday, 24 January 2018

Advancedjava-Slip11

02:27    



Slip11
Q1. Write a JDBC program to remove “percentage” column from student (rno, sname, percentage) table.  


import java.sql.*;

import java.io.*;
import javax.sql.*;

class slip11
{
            public static void main(String a[])
            {
                        Connection con;
                        Statement stmt;
                        try
                        {
                                    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                                    con=DriverManager.getConnection("jdbc:odbc:lab.dsn");
                                   
                                    
                                    stmt=con.createStatement();
                                    int no = stmt.executeUpdate("alter table student drop column per");
                                    if(no!=0)
                                                System.out.println("Drop col sucessfully");
                                    else
                                                System.out.println("NOT Drop col ");
                        }
                        catch(Exception e)
                        {
                                    System.out.println(e);
                        }
            }
}

 
                                                                                                                
Q2. Write a SERVLET program to change inactive time interval of session.          

 import java.util.*;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class slip11 extends HttpServlet {
  
  public void doGet(HttpServletRequest req, HttpServletResponse res)
                               throws ServletException, IOException {
    res.setContentType("text/html");
    PrintWriter out = res.getWriter();

    // Get the current session object, create one if necessary
    HttpSession session = req.getSession();

    out.println("<HTML><HEAD><TITLE>SessionTimer</TITLE></HEAD>");
    out.println("<BODY><H1>Session Timer</H1>");

    // Display the previous timeout
    out.println("The previous timeout was " +
                session.getMaxInactiveInterval());
    out.println("<BR>");

    // Set the new timeout
    session.setMaxInactiveInterval(2*60*60);  // two hours

    // Display the new timeout
    out.println("The newly assigned timeout is " +
                session.getMaxInactiveInterval());

    out.println("</BODY></HTML>");
  }
}
Another way

import java.io.*;
import java.lang.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class ses extends HttpServlet implements Servlet
{

  protected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException
{
HttpSession session=request.getSession(true);
Integer cnt=(Integer)session.getAttribute("mycnter");

  response.setContentType("text/html");

  PrintWriter out = response.getWriter();
  if(cnt==null)
  {
            cnt=new Integer(0);
            out.print("Welcome.....");
  }
  else
  {
            String uname=request.getParameter("tname");
            Cookie cookie = new Cookie("uname",uname);
            cookie.setMaxAge(365*24*60*60);
            response.addCookie(cookie);
            out.println("cookie Added");
            if(uname!= null) session.setAttribute("who",uname);
            else uname =(String)session.getAttribute("who");
            cnt=new Integer(cnt.intValue()+1);
            out.print("<h1>Welcome back"+uname+"<h1>");
            out.println("This is your visit no. "+cnt+"<BR>");
  }
session.setAttribute("mycnter",cnt);
}
}