Java Cart CategoryScreenWrangler java

package cart.screenWranglers;

import cart.Category;
import cart.Item;
import cart.applicationBeans.CategoryBean;
import cart.applicationBeans.ItemBean;
import cart.applicationBeans.ItemCategoryBean;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.ListIterator;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.ServletContext;

//CategoryScreenWrangler
//author - Lawrence Truett - FluffyCat.com
//date - June 6, 2003 - San Diego, CA
public class CategoryScreenWrangler extends BaseScreenWrangler {
    
    public CategoryScreenWrangler() {this("/cart/jsps/Category.jsp");}
    
    public CategoryScreenWrangler(String nextScreenIn) {
        super(nextScreenIn);
    }
    
    public void wrangleScreen(HttpServletRequest request, 
        ServletContext servletContext) 
    {
        
        char action = baseNextScreenSwitch(request, 
                                           servletContext);

        if (action != 'C') {
            getNextWrangler().prepFirstScreen(request, 
                                              servletContext);
        } else {
            StringBuffer catSubs = this.allScreens(request, 
                                                   servletContext);
            request.setAttribute("jspCatList", catSubs);
            HttpSession httpSession = request.getSession();
            httpSession.setAttribute("prevQueryString", 
                                      request.getQueryString());
            httpSession.setAttribute("prevAction", action + " ");
        }
    }
    
    void prepFirstScreen(HttpServletRequest request, 
                         ServletContext servletContext) {
        StringBuffer catSubs = allScreens(request, servletContext);
        request.setAttribute("jspCatList", catSubs);
    }
    
    StringBuffer allScreens(HttpServletRequest request, 
                            ServletContext servletContext) {
        StringBuffer catSubs = new StringBuffer();
        
        CategoryBean catBean = 
        	(CategoryBean)servletContext.getAttribute(
            "categoryBean");
        
        String stringKey = request.getParameter("category");
        if (stringKey == null) {stringKey = "0";}
        request.getSession().setAttribute("lastCategory", stringKey);
        long key = Long.parseLong(stringKey);
        Category currentCat;
        
        if (key != 0) {
            Category current = catBean.getCategory(key);
            if (current != null  ) {
                catSubs.append("
CURRENT
" + 
                    current.getDescription() + "
");
            }
        }
        
        catSubs.append("
DOWN
");
        ListIterator csli = 
        	catBean.getSubCategories(key).listIterator();
        if (!csli.hasNext()) {
            catSubs.append("no sub categories
");
        }
        else {
            while (csli.hasNext()) {
                currentCat = (Category)csli.next();
                catSubs.append(
                    "<"+"a href="/servlet/servlet.ControllerServlet?"+
                    "action=C&category=");
                catSubs.append(currentCat.getKey() + "">" + 
                    currentCat.getDescription() + "" + "
");
            }
        }
        
        if (key != 0) {
            catSubs.append("
SIBLINGS
");
            ArrayList siblingsAndSelf = 
            	catBean.getChildrenForParent(key);
            csli = siblingsAndSelf.listIterator();
            if (!csli.hasNext() || siblingsAndSelf.size() == 1) {
                catSubs.append("no siblings
");
            }
            else {
                while (csli.hasNext()) {
                    currentCat = (Category)csli.next();
                    if (currentCat.getKey() != key) {
                        //don't show current cat as a sibling
                        catSubs.append("<"+
                            "a href="/servlet/servlet."+
                            "ControllerServlet?action=C&category=");
                        catSubs.append(currentCat.getKey() + "">" + 
                            currentCat.getDescription() + 
                            "" + "
");
                    }
                }
            }
        }
        
        if (key != 0) {
            Category parent = catBean.getParentCategory(key);
            if (parent != null  ) {
                catSubs.append("UP<"+"a href="/servlet/servlet."+
                               "ControllerServlet?action=C&category=");
                catSubs.append(parent.getKey() + "">" + 
                    parent.getDescription() + "" + "
");
            }
        }
        
        if (key != 0) {
            //now we get some actual items, not sure what 
            //screen this would ultimately be done on...
            catSubs.append("
ITEMS
");
            ItemCategoryBean itemCatBean = 
                (ItemCategoryBean)servletContext.
                    getAttribute("itemCategoryBean");
            ItemBean itemBean = (ItemBean)servletContext.
                getAttribute("itemBean");
            ArrayList items = itemCatBean.getItems(key);
            if ((items == null) || (items.size() == 0)) {
                catSubs.append("no items
");
            } else {
                ListIterator itemsLi = items.listIterator();
                while (itemsLi.hasNext()) {
                    Long iKey = (Long)itemsLi.next();
                    Item item = itemBean.getItem(iKey);
                    if (item != null) {
                        catSubs.append("<"+"a href="/servlet/servlet."+
                            "ControllerServlet?action=I&item=");
                        catSubs.append(item.getKey() + "">" + 
                            item.getDescription());
                        catSubs.append("<"+"img src="\cart\images\");
                        catSubs.append(item.getSmallGraphic());
                        catSubs.append(
                        		"" width="75" align="top">");
                        catSubs.append("
");
                        catSubs.append("
");
                    }
                }
            }
        }
        return catSubs;
    }
    
}