Forum:

Struts

Checking the size of an ArrayList in a JSP page

Greenhorn

Posts: 9

posted 17 years ago

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I am a beginner to Java. I am doing an assignment of a Shopping cart application. Below is the action class I have created. I want a number to display in the JSP page each time the size of the array increases. How do I call the arraylist from the servlet in the JSP page? Any help would be greatly appreciated. Thank You.

public class ItemAddToCartAction extends Action {
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {

HttpSession session = request.getSession();
try {
Hashtable item = new Hashtable();
item.put("brand", request.getParameter("brand"));
item.put("color", request.getParameter("color"));
item.put("size", request.getParameter("size"));
item.put("price", request.getParameter("price"));
item.put("shipping", request.getParameter("shipping"));
if (session.getAttribute("cart") == null) {
ArrayList cart = new ArrayList();
cart.add(item);
session.setAttribute("cart", cart);
}

else {
ArrayList cartFromSession = (ArrayList)
session.getAttribute("cart");
cartFromSession.add(item);
session.setAttribute("cart",cartFromSession);
}

} catch (Exception e) {
System.out.println("Exception occured");
return mapping.findForward("Failure");
}
return mapping.findForward("SUCCESS");

}
}

Jason Menard

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Posts: 6450

posted 17 years ago

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"SDN",

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alan do

Ranch Hand

Posts: 354

posted 17 years ago

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there are many ways to do this. here's one using scriptlets inside your JSP:

<% HttpSession session = request.getSession();
int itemsCount = ((ArrayList)request.getAttribute("cart")).size(); %>

<%=itemsCount%>

-/a<br />certified slacker...yes, my last name is 'do' - <a href="http://www.luckycouple.com" target="_blank" rel="nofollow">luckycouple.com</a>

Thara Visu

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Posts: 87

posted 17 years ago

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Alan,
It should be session.getAttribute and not request

Also adding to your point we dont even need to use request.getSession()
we can use session implicit object directly.

Thara<br />SCJP 1.4 96%<br />SCBCD 1.3 96%

Cendy Nguvy

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Posts: 37

posted 16 years ago

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Originally posted by SDN:
I am a beginner to Java. I am doing an assignment of a Shopping cart application. Below is the action class I have created. I want a number to display in the JSP page each time the size of the array increases. How do I call the arraylist from the servlet in the JSP page? Any help would be greatly appreciated. Thank You.

public class ItemAddToCartAction extends Action {
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {

HttpSession session = request.getSession();
try {
Hashtable item = new Hashtable();
item.put("brand", request.getParameter("brand"));
item.put("color", request.getParameter("color"));
item.put("size", request.getParameter("size"));
item.put("price", request.getParameter("price"));
item.put("shipping", request.getParameter("shipping"));
if (session.getAttribute("cart") == null) {
ArrayList cart = new ArrayList();
cart.add(item);
session.setAttribute("cart", cart);
}

else {
ArrayList cartFromSession = (ArrayList)
session.getAttribute("cart");
cartFromSession.add(item);
session.setAttribute("cart",cartFromSession);
}

} catch (Exception e) {
System.out.println("Exception occured");
return mapping.findForward("Failure");
}
return mapping.findForward("SUCCESS");

}
}

Cendy Nguvy

Ranch Hand

Posts: 37

posted 16 years ago

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Add this at the top of your jsp, before tag <html> :

<jsp:useBean id="cart" scope="session" type="java.util.ArrayList"/>

and in tag <body> :

<%=cart.size()%>

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