ReceiptServlet.java

package servlets;

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

import constants.IOnlineBookStoreConstants;
import sql.IBookConstants;

public class ReceiptServlet extends GenericServlet {
	public void service(ServletRequest req, ServletResponse res) throws IOException, ServletException {
		PrintWriter pw = res.getWriter();
		res.setContentType(IOnlineBookStoreConstants.CONTENT_TYPE_TEXT_HTML);
		try {
			Connection con = DBConnection.getCon();
			PreparedStatement ps = con.prepareStatement("select * from " + IBookConstants.TABLE_BOOK);
			ResultSet rs = ps.executeQuery();
			int i = 0;
			RequestDispatcher rd = req.getRequestDispatcher("ViewBooks.html");
			rd.include(req, res);
			pw.println("<div class=\"tab\">You Successfully Paid for Following Books</div>");
			pw.println(
					"<div class=\"tab\">\r\n" + "		<table>\r\n" + "			<tr>\r\n" + "				\r\n"
							+ "				<th>Book Code</th>\r\n" + "				<th>Book Name</th>\r\n"
							+ "				<th>Book Author</th>\r\n" + "				<th>Book Price</th>\r\n"
							+ "				<th>Quantity</th><br/>\r\n" + "				<th>Amount</th><br/>\r\n" + "			</tr>");
			double total = 0.0;
			while (rs.next()) {
				int bPrice = rs.getInt(IBookConstants.COLUMN_PRICE);
				String bCode = rs.getString(IBookConstants.COLUMN_BARCODE);
				String bName = rs.getString(IBookConstants.COLUMN_NAME);
				String bAuthor = rs.getString(IBookConstants.COLUMN_AUTHOR);
				int bQty = rs.getInt(IBookConstants.COLUMN_QUANTITY);
				i = i + 1;

				String qt = "qty" + Integer.toString(i);
				int quantity = Integer.parseInt(req.getParameter(qt));
				try {
					String check1 = "checked" + Integer.toString(i);
					String getChecked = req.getParameter(check1);
					if (bQty < quantity) {
						pw.println(
								"</table><div class=\"tab\">Please Select the Qty less than Available Books Quantity</div>");
						break;
					}

					if (getChecked.equals("pay")) {
						pw.println("<tr><td>" + bCode + "</td>");
						pw.println("<td>" + bName + "</td>");
						pw.println("<td>" + bAuthor + "</td>");
						pw.println("<td>" + bPrice + "</td>");
						pw.println("<td>" + quantity + "</td>");
						int amount = bPrice * quantity;
						total = total + amount;
						pw.println("<td>" + amount + "</td></tr>");
						bQty = bQty - quantity;
						System.out.println(bQty);
						PreparedStatement ps1 = con.prepareStatement("update " + IBookConstants.TABLE_BOOK + " set "
								+ IBookConstants.COLUMN_QUANTITY + "=? where " + IBookConstants.COLUMN_BARCODE + "=?");
						ps1.setInt(1, bQty);
						ps1.setString(2, bCode);
						ps1.executeUpdate();
					}
				} catch (Exception e) {
				}
			}
			pw.println("</table><br/><div class='tab'>Total Paid Amount: " + total + "</div>");
			String fPay = req.getParameter("f_pay");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}