//The HTML index page
<!DOCTYPE html>
<!--
To change this license header, choose License Headers in Project Properties.
To change this template file, choose Tools | Templates
and open the template in the editor.
-->
<html>
<head>
<title></title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<center>
<h1>Welcome to the IGNOU RC Varanasi website</h1>
<h3>Here you can have all information about counselling classes and library books</h3>
<!-- books.java is the Servlet file which should get executed/invoked once below link is clicked, -->
<div>For books availability in the library <a href="books">click here</a></div>
<!-- modifyBooks.java is the Servlet file which should get executed/invoked once below link is clicked, -->
<br><br>
<div>For modifying a book's availability status in the library
<form method="POST" action="modifyBooks">
<br><br>
enter book id <input type = "text" id ="bookId" name ="bookId">
<br><br>
enter new availability status (Yes/No) <input type = "text" id ="status" name ="status">
<br><br>
<button type="submit"> Update </button>
</form>
</div>
</center>
</body>
</html>
-----------------------------------------------------------------------------------------------------------
//The 'books.java' servlet
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package Library;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
*
* @author ashu
*/
public class books extends HttpServlet {
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code>
* methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try{
out.println("<html>");
out.println("<head><title>Servlet JDBC</title></head>");
out.println("<body>");
// connecting to database
Class.forName("com.mysql.jdbc.Driver");
Connection con =DriverManager.getConnection ("jdbc:mysql://localhost/dbmsbooks","root","ashutosh");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM dbbooks");
// displaying records
out.println("<center>");
out.println("<h1>IGNOU RC Varanasi website</h1>");
out.println("<h2>"+"Following is the details of the books available in library related to DBMS: "+"</h2>");
out.println("<table border=1>");
out.println("<tr><th>BookID</th><th>Title</th><th>Authors</th><th>Publication</th><th>Availability</th></tr>");
while(rs.next()){
out.println("<tr>");
out.println("<td>"+rs.getInt(1)+"</td>"+
"<td>"+rs.getString(2)+"</td>"+
"<td>"+rs.getString(3)+"</td>"+
"<td>"+rs.getString(4)+"</td>"+
"<td>"+rs.getString(5)+"</td>");
out.println("</tr>");
}
out.println("</center></body></html>");
} catch (SQLException e) {
throw new ServletException("Servlet Could not display records.", e);
} catch (ClassNotFoundException e) {
throw new ServletException("JDBC Driver not found.", e);
}
out.close();
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</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 doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* 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>
}
-----------------------------------------------------------------------------------------------------
//The 'modifyBooks.java' servlet
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package Library;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author ashu
*/
@WebServlet(name = "modifyBooks", urlPatterns = {"/modifyBooks"})
public class modifyBooks extends HttpServlet {
/**
*
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
response.setContentType("text/html;charset=UTF-8");
try(PrintWriter out = response.getWriter()) {
try{
out.println("<html>");
out.println("<head><title>Servlet JDBC</title></head>");
out.println("<body>");
// connecting to database
Class.forName("com.mysql.jdbc.Driver");
Connection con =DriverManager.getConnection ("jdbc:mysql://localhost/dbmsbooks","root","ashutosh");
Statement stmt = con.createStatement();
String bookId = request.getParameter("bookId");
String status = request.getParameter("status");
//out.println(bookId);
//out.println(status);
stmt.executeUpdate("UPDATE dbbooks SET available = '" + status + " 'WHERE bookID = "+bookId+";");
out.println("Book status updated successfuly!");
out.println("</body></html>");
} catch (SQLException e) {
throw new ServletException("Servlet Could not display records.", e);
} catch (ClassNotFoundException e) {
throw new ServletException("JDBC Driver not found.", e);
}
} }
------------------------------------------------------------------------------------------------------------
Output:
Home page:
Books details
BookID 1 status change from 'yes' to 'no' request made
Change done successfuly
Verify the change by seeing books details once again
