SERVLET/JSP Realization Shopping Cart

(1) using the servlet to implement a simple shopping cart system, the project structure such as the following: (New Web project projects only need Additemservlet, Listitemservlet. Exam403.jsp three files is available. Other no-tube)

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(2) Exam403.jsp code such as the following:

<%@ page contenttype= "text/html; charset=gb2312 "language=" java "import=" java.sql.* "errorpage=" "%><! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
(3) Additemservlet code such as the following:
Package Com.lc.shoppingcar;import Javax.servlet.*;import javax.servlet.http.*;import java.io.*;import java.util.*; public class Additemservlet extends HttpServlet {protected void doget (HttpServletRequest request,httpservletresponse R Esponse) throws Servletexception,java.io.ioexception {ServletContext Application=getservle      Tcontext ();      ServletConfig Config=getservletconfig ();      Response.setcontenttype ("text/html;charset=gb2312");       PrintWriter Out=response.getwriter ();      HttpSession session =request.getsession ();            Request.setcharacterencoding ("gb2312");  Read the incoming Product ID and number of the form String id=request.getparameter ("ItemID"); String num=request.getparameter ("Quantity"); if (Id!=null && num.length ()!=0) {//read from Sessionn shopping cart HashMap shoppingcar= (HashMap) Session.getattribute ("    Shoppingcar ");    if (shoppingcar==null) shoppingcar=new HashMap ();    Add the item to the shopping cart string onum= (String) shoppingcar.get (ID);     if (onum==null)   Shoppingcar.put (Id,num);   else {int n1=integer.parseint (num);   int N2=integer.parseint (onum);   String result=string.valueof (N1+N2);     Shoppingcar.put (Id,result);    }//The shopping cart is written back to the session to save Session.setattribute ("Shoppingcar", Shoppingcar); } else//Assume that the incoming Product ID number is empty or the quantity is empty. Display the message System.out.print ("The Product ID number is empty or the quantity is empty!")  ");         Return to Product List page response.sendredirect ("/servletproject/exam403.jsp"); } protected void DoPost (HttpServletRequest request,httpservletresponse response) throw  S servletexception,java.io.ioexception {doget (request,response); }}

(4) Listitemservlet code such as the following:
Package Com.lc.shoppingcar;import Javax.servlet.*;import javax.servlet.http.*;import java.io.*;import java.util.*; public class Listitemservlet extends HttpServlet {protected void doget (HttpServletRequest request,httpservletresponse Response) throws Servletexception,java.io.ioexception {ServletContext APPLICATION=GETSERVL      Etcontext ();      ServletConfig Config=getservletconfig ();      Response.setcontenttype ("text/html;charset=gb2312");       PrintWriter Out=response.getwriter ();      HttpSession session =request.getsession ();             Request.setcharacterencoding ("gb2312");  Get shopping cart from session HashMap shoppingcar= (HASHMAP) session.getattribute ("Shoppingcar");      Displays the contents of the shopping cart if (shoppingcar!=null) {Set show=shoppingcar.entryset ();      Iterator It=show.iterator ();       while (It.hasnext ()) {Out.print (It.next () + "<br>"); }} else Out.print ("The shopping cart is empty.       "); } protected void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception,java.io.ioexception {doget (req  Uest,response); }}

(5) Implementation effects such as the following:
Interview: Http://localhost:8080/servletProject/exam403.jsp product submission

Click to view Cart:

Ok!
This is the end of a simple shopping cart!
 
SERVLET/JSP Realization Shopping Cart