Jsp + Servlet to implement the shopping cart function, servlet shopping cart

Last Update:2017-08-11 Source: Internet

Author: User

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This article provides examples of how to use Servlet to implement the shopping cart function for your reference. The details are as follows:

(1) Use servlet to implement a simple Shopping Cart system. The Project structure is as follows: (to create a web Project, only AddItemServlet and ListItemServlet are required. Exam403.jsp. Others)

(2) The exam403.jsp code is as follows:

<% @ 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 "> <Html xmlns =" http://www.w3.org/1999/xhtml "> <Head> <meta http-equiv =" Content-Type "content =" text/html; charset = gb2312 "/> <title> untitled document </title> 
(3) The AddItemServlet code is as follows:

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 response) throws ServletException, java. io. IOException {ServletContext application = getServletContext (); ServletConfig config = getServletConfig (); response. setContentTyp E ("text/html; charset = gb2312"); PrintWriter out = response. getWriter (); HttpSession session = request. getSession (); request. setCharacterEncoding ("gb2312"); // read the product ID and quantity passed in the form. String id = request. getParameter ("itemID"); String num = request. getParameter ("quantity"); if (id! = Null & num. length ()! = 0) {// read the shopping cart HashMap shoppingCar = (HashMap) session from Sessionn. 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);} // write the shopping cart back to the session to save the session. setAtt Rigoal ("shoppingCar", shoppingCar);} else // assume that the input item ID number is null or the number is null. The System. out. print ("the item ID is blank or the number is blank! "); // Return to the product list page response. sendRedirect ("/servletProject/exam403.jsp");} protected void doPost (HttpServletRequest request, HttpServletResponse response) throws ServletException, java. io. IOException {doGet (request, response );}}
(4) The ListItemServlet code is as follows:

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 = getServletContext (); ServletConfig config = getServletConfig (); response. setContentTy Pe ("text/html; charset = gb2312"); PrintWriter out = response. getWriter (); HttpSession session = request. getSession (); request. setCharacterEncoding ("gb2312"); // obtain the cart HashMap shoppingCar = (HashMap) session from the session. getAttribute ("shoppingCar"); // 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 (request, response );}}
(5) The implementation effect is as follows:

Question: http: // localhost: 8080/servletProject/exam403.jsp submit the product


Click to view the shopping cart:


OK!
This is the end of a simple shopping cart!
The above is all the content of this article. I hope it will be helpful for your learning and support for helping customers.

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