//file: ShoppingCart.java
import java.io.*;
import javax.servlet.ServletException;
import javax.servlet.http.*;
import java.util.Enumeration;
public class ShoppingCart extends HttpServlet {
// from your database
String [] items = new String [] {
"Chocolate Covered Crickets", "Raspberry Roaches",
"Buttery Butterflies", "Chicken Flavored Chicklets(tm)" };
public void doPost( HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
doGet( request, response );
}
public void doGet( HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter( );
// get or create the session information
HttpSession session = request.getSession( );
int [] purchases = (int [])session.getValue("purchases");
if ( purchases == null ) {
purchases = new int [ items.length ];
session.putValue( "purchases", purchases );
}
out.println( "<html><head><title>Shopping Cart</title>"
+ "</title></head><body><p>" );
if ( request.getParameter("checkout") != null )
out.println("<h1>Thanks for ordering!</h1>");
else {
if ( request.getParameter("add") != null ) {
addPurchases( request, purchases );
out.println(
"<h1>Purchase added. Please continue</h1>");
} else {
if ( request.getParameter("clear") != null )
for (int i=0; i<purchases.length; i++)
purchases[i] = 0;
out.println("<h1>Please Select Your Items!</h1>");
}
doForm( out, purchases, request.getRequestURI( ) );
}
showPurchases( out, purchases );
out.close( );
}
void addPurchases( HttpServletRequest request,
int [] purchases ) {
for (int i=0; i<items.length; i++) {
String added = (String)request.getParameter( items[i] );
if ( !added.equals("") )
purchases[i] += Integer.parseInt( added );
}
}
void doForm( PrintWriter out, int [] purchases,
String requestURI) {
out.println( "<form method=POST action="+ requestURI +">" );
for(int i=0; i< items.length; i++)
out.println( "Quantity <input name=\"" + items[i]
+ "\" value=0 size=3> of: " + items[i] + "<br>");
out.println(
"<p><input type=submit name=add value=\"Add To Cart\">"
+ "<input type=submit name=checkout value=\"Check Out\">"
+ "<input type=submit name=clear value=\"Clear Cart\">"
+ "</form>" );
}
void showPurchases( PrintWriter out, int [] purchases )
throws IOException {
out.println("<hr><h2>Your Shopping Basket</h2>");
for (int i=0; i<items.length; i++)
if ( purchases[i] != 0 )
out.println( purchases[i] +" "+ items[i] +"<br>" );
}
}
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