Structure Query Language, C programming, Java, Servlet, Jsp, Unix

Sunday 22 April 2012

Develop a Java application to perform the database driven operation like insert, Delete, Update and selection using PreparedStatement. To perform the above operations use the table from above exercise.

[pro29index.jsp]


<html>
<head>
<script language="javascript">
function valid_num()
{
e=event.keyCode;
//alert(e);
if( !(e>=48 && e<=57))
{
event.keyCode=0;
}
}
</script>
</head>
<body>
<table align=center cellpadding=10>
<tr>
<td><img src="logo.jpg"/>
</table>

<table align=center width=100% cellpadding=5>
<tr>
<td colspan=2 align="center"><h2><i>DATABASE DRIVEN OPERATIONS</i></h2>
<tr>
<td align="right" colspan=2><a href="http://master-gtu.blogspot.com">www.master-gtu.blogspot.com</a>
<tr>
<td valign=top>
<form name="f1" action="pro29">
<table>
<tr>
<td>Employee ID
<td><input type="text" name="empid">
<td><input type="submit" value="search" onclick="document.f1.flag.value=1;document.f1.fn.value='empid';document.f1.action='pro29index.jsp'">
<tr>
<td>Employee NAME
<td><input type="text" name="empname">
<td><input type="submit" value="search" onclick="document.f1.flag.value=2;document.f1.fn.value='empname';document.f1.action='pro29index.jsp'">
<tr>
<td>Employee DISIGNATION
<td><input type="text" name="emp_desig">
<td><input type="submit" value="search" onclick="document.f1.flag.value=3;document.f1.fn.value='emp_desig';document.f1.action='pro29index.jsp'">
<tr>
<td>Employee JOIN DATE
<td><input type="text" name="emp_j_date">
<tr>
<td>Employee SALARY
<td><input type="text" name="emp_salary">
<tr>
<td colspan=3>
<input type="submit" name="insert" value="INSERT" onclick="document.f1.flag.value=5">
<input type="submit" name="DELETE" value="DELETE" onclick="document.f1.flag.value=6">
<input type="submit" name="update" value="UPDATE" onclick="document.f1.flag.value=7">
<input type="submit" name="view" value="VIEW ALL" onclick="document.f1.action='pro29index.jsp'">
</table>
<input type="hidden" name="flag" value="">
<input type="hidden" name="fn" value="">
</form>
<%
String msg=request.getParameter("msg");
if(msg!=null)
out.println("<font color=red>"+msg+"</font>");
%>
<td>
<jsp:include page="/pro29showtable.jsp"/>
</table>
</body>
</html>


[pro29showtable.jsp]


<%@ page import="java.sql.*" %>
<table border=5><tr><td>
<table cellpadding=10>
<tr bgcolor="limegreen">
<th>Empid<th>Empname<th>emp_desig<th>emp_j_date<th>emp_salary
<%
String q;
boolean flag=false;
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");

String fn=request.getParameter("fn");
String value=request.getParameter(fn);

if(fn=="" || fn==null)
{
q="select * from employee";
}
else
{
q="select * from employee where "+fn+" LIKE  ?";
flag=true;
}

PreparedStatement ps=con.prepareStatement(q);


if(flag)
ps.setString(1,value);

ResultSet rs=ps.executeQuery();

while(rs.next())
{
%>
<tr>
<td><%= rs.getInt(1) %>
<td><%= rs.getString(2) %>
<td><%= rs.getString(3) %>
<td><%= rs.getString(4) %>
<td><%= rs.getString(5) %>
<%
}
rs.close();
ps.close();
con.close();
}catch(Exception e){ out.println("error found:"+e);}
%>
</table></table>


[pro29.java]


import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
@WebServlet("/pro29")
public class pro29 extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException
{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
String q;
String msg="";
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
PreparedStatement ps=con.prepareStatement("select * from employee");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select * from employee");
String empid=req.getParameter("empid");
String empname=req.getParameter("empname");
String emp_desig=req.getParameter("emp_desig");
String emp_j_date=req.getParameter("emp_j_date");
String emp_salary=req.getParameter("emp_salary");

int flag=Integer.parseInt(req.getParameter("flag"));
if(empid.equals(""))
{
msg="Enter EmpID first";
flag=1;
}

switch(flag)
{
case 4:
out.println("4 selected");
break;
case 5:

rs=stmt.executeQuery("select * from employee where empid='"+empid+"'");
if(!rs.next())
{
q="insert into employee values(?,?,?,?,?)";
ps=con.prepareStatement(q);
ps.setString(1,empid);
ps.setString(2,empname);
ps.setString(3,emp_desig);
ps.setString(4,emp_j_date);
ps.setString(5,emp_salary);
msg="Insert Record Successfully...";
}
else
{
msg="Employee Id Already Exist...";
}


break;
case 6:
rs=stmt.executeQuery("select * from employee where empid='"+empid+"'");
if(rs.next())
{
q="delete from employee where empid=?";
ps=con.prepareStatement(q);
ps.setString(1,empid);
msg="Delete Record Successfully...";
}
else
{
msg="Employee Not Exist...";
}


break;
case 7:
rs=stmt.executeQuery("select * from employee where empid='"+empid+"'");
if(rs.next())
{
q="update employee set empname=?, emp_desig=?, emp_j_date=?, emp_salary=? where empid=?";
ps=con.prepareStatement(q);
ps.setString(1,empname);
ps.setString(2,emp_desig);
ps.setString(3,emp_j_date);
ps.setString(4,emp_salary);
ps.setString(5,empid);
msg="Update Record Successfully...";
}
else
{
msg="Employee Not Exist...";
}


break;
}
ps.executeQuery();
stmt.close();
ps.close();
con.close();

}catch(Exception e){}
res.sendRedirect("pro29index.jsp");
}
}

Develop a program to perform the database driven operation like insert, Delete, Update and select. To perform the above operations create one table named Employee. Field Name Field Type EmpId Integer Empname Varchar Emp_desig Varchar Emp_J_Date Varchar Emp_Salary Numeric


[pro28index.jsp]

<html>
<head>
<script language="javascript">
function valid_num()
{
e=event.keyCode;
//alert(e);
if( !(e>=48 && e<=57))
{
event.keyCode=0;
}
}
</script>
</head>
<body>
<table align=center cellpadding=10>
<tr>
<td><img src="logo.jpg"/>
</table>

<table align=center width=100% cellpadding=5>
<tr>
<td colspan=2 align="center"><h2><i>DATABASE DRIVEN OPERATIONS</i></h2>
<tr>
<td align="right" colspan=2><a href="http://master-gtu.blogspot.com">www.master-gtu.blogspot.com</a>
<tr>
<td valign=top>
<form name="f1" action="pro28">
<table>
<tr>
<td>Employee ID
<td><input type="text" name="empid" name="search" onkeypress="valid_num()">
<td><input type="submit" value="search" onclick="document.f1.flag.value=1;document.f1.fn.value='empid';document.f1.action='pro28index.jsp'">
<tr>
<td>Employee NAME
<td><input type="text" name="empname">
<td><input type="submit" value="search" onclick="document.f1.flag.value=2;document.f1.fn.value='empname';document.f1.action='pro28index.jsp'">
<tr>
<td>Employee DISIGNATION
<td><input type="text" name="emp_desig">
<td><input type="submit" value="search" onclick="document.f1.flag.value=3;document.f1.fn.value='emp_desig';document.f1.action='pro28index.jsp'">
<tr>
<td>Employee JOIN DATE
<td><input type="text" name="emp_j_date">
<tr>
<td>Employee SALARY
<td><input type="text" name="emp_salary" onkeypress="valid_num()">
<tr>
<td colspan=3>
<input type="submit" name="insert" value="INSERT" onclick="document.f1.flag.value=5">
<input type="submit" name="DELETE" value="DELETE" onclick="document.f1.flag.value=6">
<input type="submit" name="update" value="UPDATE" onclick="document.f1.flag.value=7">
<input type="submit" name="view" value="VIEW ALL">
</table>
<input type="hidden" name="flag" value="">
<input type="hidden" name="fn" value="">
</form>
<%
String msg=request.getParameter("msg");
if(msg!=null)
out.println("<font color=red>"+msg+"</font>");
%>
<td>
<jsp:include page="/pro28showtable.jsp"/>
</table>
</body>
</html>

[pro28showtable.jsp]


<%@ page import="java.sql.*" %>
<table border=5><tr><td>
<table cellpadding=10>
<tr bgcolor="limegreen">
<th>Empid<th>Empname<th>emp_desig<th>emp_j_date<th>emp_salary
<%
String q;
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
String fn=request.getParameter("fn");
String value=request.getParameter(fn);


if(fn=="" || fn==null)
q="select * from employee";
else
q="select * from employee where "+fn+"='"+value+"'";

ResultSet rs=stmt.executeQuery(q);

while(rs.next())
{
%>
<tr>
<td><%= rs.getInt(1) %>
<td><%= rs.getString(2) %>
<td><%= rs.getString(3) %>
<td><%= rs.getString(4) %>
<td><%= rs.getString(5) %>
<%
}
rs.close();
stmt.close();
con.close();
}catch(Exception e){ out.println("error found:"+e);}
%>
</table></table>

[pro28.java]


import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
@WebServlet("/pro28")
public class pro28 extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException
{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
String q;
String msg="";
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select * from employee");
String empid=req.getParameter("empid");
String empname=req.getParameter("empname");
String emp_desig=req.getParameter("emp_desig");
String emp_j_date=req.getParameter("emp_j_date");
String emp_salary=req.getParameter("emp_salary");

int flag=Integer.parseInt(req.getParameter("flag"));
if(empid.equals(""))
{
msg="Enter EmpID first";
flag=1;
}
switch(flag)
{
case 4:
out.println("4 selected");
break;
case 5:
rs=stmt.executeQuery("select * from employee where empid='"+empid+"'");
if(!rs.next())
{
q="insert into employee values('"+empid+"','"+empname+"','"+emp_desig+"','"+emp_j_date+"','"+emp_salary+"')";
stmt.executeQuery(q);
msg="Insert Record Successfully...";
}
else
{
msg="Employee Id Already Exist...";
}
break;
case 6:
rs=stmt.executeQuery("select * from employee where empid='"+empid+"'");
if(rs.next())
{
q="delete from employee where empid='"+empid+"'";
stmt.executeQuery(q);
msg="Delete Record Successfully...";
}
else
{
msg="Employee Not Exist...";
}
break;
case 7:

rs=stmt.executeQuery("select * from employee where empid='"+empid+"'");
if(rs.next())
{
q="update employee set empname='"+empname+"', emp_desig='"+emp_desig+"', emp_j_date='"+emp_j_date+"', emp_salary='"+emp_salary+"' where empid='"+empid+"'";
stmt.executeQuery(q);
msg="Updated Record Successfully...";
}
else
{
msg="Employee Not Exist...";
}
break;
}
rs.close();
stmt.close();
con.close();

}catch(Exception e){}
res.sendRedirect("pro28index.jsp?msg="+msg);
}
}


Write a JSP Page to which uses Session Tracking for online shopping.


[pro37index.jsp]


<%@ page import="java.sql.*" %>
<%
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select img,name from books");
%>
<html>
<head>
<title>ONLINE BOOK STORE - LOGIN PAGE</title>
</head>
<body>
<table align=center>
<tr>
<td align=center><img src="logo.jpg"></img>
<tr>
<td align=right><a href="http://master-gtu.blogspot.com">www.master-gtu.blogspot.com</a>
</table>
<table border=0 width=100% height=60% >
<tr>
<td colspan=5 align=center><h2>WELCOME TO ONLINE BOOK SHOPPING</h2>
<tr>
<td width=70% >
<marquee>
<table cellpadding=2 cellspacing=8>
<tr>
<%
while(rs.next())
{
%>
<td>
<img src="<%="images/"+rs.getString("img") %>" width=100 height=150>
<%
}
%>
<tr>
<%
rs=stmt.executeQuery("select img,name from books");
while(rs.next())
{
%>
<td><%=rs.getString("name")%>
<%
}
%>
</table>
</marquee>
<td align=center valign=top>
<i><h2>LOGIN</h2></i>
<form action="pro37logincheck" method="post">
<table>
<tr>
<td>USERNAME
<td><input type="text" name="username">
<tr>
<td>PASSWORD
<td><input type="text" name="password">
<tr>
<td colspan=2>
<%
String msg=request.getParameter("msg");
if(msg!=null)
out.println("<font color=red>"+msg+"</font>");
%>
<tr>
<td><input type="submit" name="LOGIN">
<td><input type="submit" name="CLEAR">
</table>
</form>
</table>
</body>
</html>
<%
rs.close();
stmt.close();
con.close();
}catch(Exception e){}
%>

[pro37purchase.jsp]


<%@ page import="java.sql.*" %>

<%
int amt=0,sno=1;
String userid=String.valueOf(session.getAttribute("userid")); //converting to string becouse session will return Object type
String name=String.valueOf(session.getAttribute("name"));

try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select * from usercart where userid='"+userid+"'");
%>
<html>
<script language="javascript">
function purchase()
{
crno=document.getElementById("crno").value;
if(crno.length==10 )
alert('HIIIIII <%=name %> YOUR PAYMENT IS DONE,                         THANKING YOU !!! :-)');
else
alert('Pls Enter Proper Credit Card Number..');
//response.sendRedirect("/pro37showbooks.jsp");
}
</script>
<body>
<table align=center>
<tr>
<td align=center colspan=4><img src="logo.jpg"></img>
</table>
<table border=20 width=100% align=center><tr><td>
<table align=center>
<tr>
<th align=center colspan=5><h2><i>USER-BILL</i></h2>
<tr>
<td width=70% colspan=3>
<td colspan=5 >
<b>Name : <%=name %></b>
<tr bgcolor=limegreen>
<th>SERIAL NO
<th>NAME OF PRODUCT
<th>PER PRICE
<th>QUANTITY
<th>PRICE
<%
while(rs.next())
{
%>
<tr>
<td><%=sno%>
<td><%=rs.getString("name") %>
<td><%=rs.getString("price")  %><br>
<td><%=rs.getString("quantity") %>
<td><%=Integer.parseInt(rs.getString("quantity")) *  Integer.parseInt(rs.getString("price"))  %><br>
<%
amt=amt+(Integer.parseInt(rs.getString("quantity")) *  Integer.parseInt(rs.getString("price")));
sno++;
%>
<%
}
%>
<tr>
<td colspan=4 align=right>TOTAL AMOUNT
<td><%=amt %>
<tr>
<td width=70% colspan=3>
<td colspan=5 >
master-gtu.blogspot.com<br>
pankaj & vijay<br>
MCA - 4<br>
<tr>
<th colspan=5> Credit Card Number : <input type="text" id="crno" ><br>
<input type="button" name="pay" value="           PAY AMOUNT       " onclick="purchase()">
<DIV ALIGN=RIGHT><a href="pro37showbooks.jsp">BACK TO HOME<a></DIV>
</table>
</table>
</body>
</html>
<%
}catch(Exception e){ out.println(e); }
%>

[pro37showbooks.jsp]


<%@ page import="java.sql.*" %>
<%
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
String cat=request.getParameter("cat");
String userid=String.valueOf(session.getAttribute("userid"));
String name=String.valueOf(session.getAttribute("name"));
ResultSet rs;
if(cat!=null)
rs=stmt.executeQuery("select * from books where cat='"+cat+"'");
else
rs=stmt.executeQuery("select * from books");
%>
<html>
<head>
<title>ONLINE BOOK STORE - LOGIN PAGE</title>
</head>
<body>
<table align=center>
<tr>
<td align=center><img src="logo.jpg"></img>
<tr>
<td align=right><a href="http://master-gtu.blogspot.com">www.master-gtu.blogspot.com</a>
</table>
<table border=0 width=100% height=60% >
<tr>
<td width=20% valign=top>
<br><br><br><br><i><font face="MonoTypeCorsiva">SELECT CATEGORY</face></i><br><br>
<jsp:include page="pro37showlist.jsp"/>
<td>
<table border=1 cellpadding=5 cellspacing=10 width=100% height=100% >
<tr height=10% align=right>
<td colspan=5>
Welcome <%=name %> | <a href="pro37showcart.jsp">Show My Cart</a> | My Account | <a href="pro37logout">Logout</a>
<%
while(rs.next())
{
%>
<tr>
<td width=10>
<td><img src="<%="images/"+rs.getString("img") %>" width=100 height=150>
<td>
Name : <%=rs.getString("name")  %><br>
Author : <%=rs.getString("auth")  %><br>
Price : <%=rs.getString("price")  %><br>
Status :
<%
if(rs.getString("quantity").equals("0"))
{
out.println("<font color=red>Not Available</font>");
}
else
{
%>
<font color=green>Available</font>
<td>
<form action="pro37addtocart" name="formsubmit" method=post>
<input type="hidden" name="cat" value=<%=rs.getString("cat") %>>
<input type="hidden" name="id" value=<%=rs.getString("id") %>>
<input type="hidden" name="totalq" value=<%=rs.getString("quantity") %>>
<input type="hidden" name="price" value=<%=rs.getString("price") %>>
Quantity
<select name="selq">
<option value=1>1</option>
<option value=2>2</option>
<option value=3>3</option>
<option value=4>4</option>
<option value=5>5</option>
<option value=6>6</option>
<option value=7>7</option>
<option value=8>8</option>
<option value=9>9</option>
<option value=10>10</option>
</select><br><input type=submit value="ADD TO CART">
<%-- <a href="" onclick="javascript:alert(document.formsubmit.action)">slfj</a> --%>
</form>
<%
}
%>
<%
}
%>
</table>
</table>
</body>
</html>
<%
}catch(Exception e){ out.println(e);}
%>

[pro37showcart.jsp]


<%@ page import="java.sql.*,java.util.*" %>
<%
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
String cat=request.getParameter("cat");
String userid=String.valueOf(session.getAttribute("userid")); //converting to string becouse session will return Object type
String name=String.valueOf(session.getAttribute("name"));
ResultSet rs;
rs=stmt.executeQuery("select * from usercart where userid='"+userid+"'");
%>
<html>
<head>
<title>ONLINE BOOK STORE - LOGIN PAGE</title>
</head>
<body>
<table align=center>
<tr>
<td align=center><img src="logo.jpg"></img>
<tr>
<td align=right><a href="http://master-gtu.blogspot.com">www.master-gtu.blogspot.com</a>
</table>
<table border=0 width=100% height=60% >
<tr>
<td width=20% valign=top>
<br><br><br><br><i><font face="MonoTypeCorsiva">SELECT CATEGORY</face></i><br><br>
<jsp:include page="pro37showlist.jsp"/>
<td>
<table border=1 cellpadding=5 cellspacing=10 width=100% height=100% >
<tr height=10% align=right>
<td colspan=5>
Welcome <%=name %> | <a href="pro37showcart.jsp">Show My Cart</a> | My Account | <a href="pro37logout">Logout</a>
<%
while(rs.next())
{
%>
<tr>
<td width=10>
<td><img src="<%="images/"+rs.getString("img") %>" width=100 height=150>
<td>
Name : <%=rs.getString("name")  %><br>
Author : <%=rs.getString("auth")  %><br>
Price : <%=Integer.parseInt(rs.getString("quantity")) *  Integer.parseInt(rs.getString("price"))  %><br>
Quantity : <%= rs.getString("quantity") %><br>
<%
}
%>
<tr>
<td colspan=3><a href="pro37purchase.jsp">PURCHASE</a>
</table>
</table>
</body>
</html>
<%
rs.close();
stmt.close();
con.close();
}catch(Exception e)
out.println(e);}
%>


[pro37showlist.jsp]


<ul>
<li><a href="pro37showbooks.jsp?cat=java">WTAD</a>
<li><a href="pro37showbooks.jsp?cat=network">FON</a>
<li><a href="pro37showbooks.jsp?cat=java">JAVA</a>
<li>MIS
<li>ANDROID
<li><a href="pro37showbooks.jsp?cat=c">C</a>
<li>C++
</ul>

[pro37logincheck.java]


import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
@WebServlet("/pro37logincheck")
public class pro37logincheck extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
String msg="Username Or Password Incorrect....";
try{
String username,password;
username=req.getParameter("username");
password=req.getParameter("password");
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select * from userinfo where username='"+username+"' and password='"+password+"'");
if(rs.next())
{
HttpSession session=req.getSession(true);
session.setAttribute("userid",rs.getString("userid"));
session.setAttribute("name",rs.getString("username"));
res.sendRedirect("pro37showbooks.jsp");
}
else
{
res.sendRedirect("pro37index.jsp?msg="+msg);
}
}catch(Exception e){ out.println(e); }
}
public void doPost(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
{
doGet(req,res);
}
}

[pro37addtocart.java]

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
@WebServlet("/pro37addtocart")
public class pro37addtocart extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
{
String cat="",id,msg="Username Or Password Incorrect....",userid,name,auth,img;
int quantity,price,selq,totalq;
HttpSession session=req.getSession(false);
userid=String.valueOf(session.getAttribute("userid"));
try{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","pankaj");
Statement stmt=con.createStatement();
ResultSet rs;
id=req.getParameter("id");
selq=Integer.parseInt(req.getParameter("selq"));
rs=stmt.executeQuery("select * from books where id="+id);
rs.next();
totalq=Integer.parseInt(rs.getString("quantity"));
price=Integer.parseInt(rs.getString("price"));
name=rs.getString("name");
img=rs.getString("img");
cat=rs.getString("cat");
auth=rs.getString("auth");
quantity=totalq - selq;
rs=stmt.executeQuery("update books set quantity="+quantity+" where id="+id);
stmt.executeQuery("insert into usercart values('"+userid+"','"+id+"','"+selq+"','"+name+"','"+img+"','"+auth+"','"+cat+"','"+price+"')");

rs.close();
stmt.close();
con.close();
}catch(Exception e){}
res.sendRedirect("pro37showbooks.jsp?cat="+cat);
}
public void doPost(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
{
doGet(req,res);
}
}

[pro37logout.java]

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
@WebServlet("/pro37logout")
public class pro37logout extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
String msg="Logout Successfully....";
HttpSession session=req.getSession(true);
session.invalidate();
res.sendRedirect("pro37index.jsp?msg="+msg);
}
public void doPost(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
{
doGet(req,res);
}
}