Java Cart CategoryBean java

package cart.applicationBeans;

import cart.Category;
import cart.dbUtils.CategoryDBUtil;
import cart.dbUtils.DBConnection;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.ListIterator;

//CategoryBean - loads all categories into a structure for display,
//                 one data load for all users,
//                 also could determine which categories are displayed
//                    using avail dates, in stock, etc...
//                 if you have too many categories for this structure
//                    to work, consider calling the dbms directly or
//                    a buffering structure like ItemBean
//author - Lawrence Truett - FluffyCat.com
//date - May 21, 2003 - San Diego, CA
public class CategoryBean {
    private HashMap categories;
    
    //must have empty constructor to be a bean
    public CategoryBean() {
        //buildCategories(dbc);
    }
    
    public CategoryBean(DBConnection dbc) {
        buildCategories(dbc);
    }
    
    public Category getCategory(long key) {
        return 
      ((CategoryPlus)(categories.get(new Long(key)))).getCategory();
    }
    
    public ArrayList getSubCategories(long key) {
        return 
      ((CategoryPlus)(categories.get(new Long(key)))).getChildren();
    }
    
    //needs a dbc, could load into a HashMap if this is used much, 
    //    alternative is getChildrenFor Parent
    public ArrayList getSiblingCategories(long key, DBConnection dbc) {
        return CategoryDBUtil.getSiblingCategoriesForKey(key,dbc);
    }
    
    //an alternative to getSiblingCategories, 
    //    may actually turn out to be more efficent
    public ArrayList getChildrenForParent(long key) {
        return getSubCategories((getParentCategory(key).getKey()));
    }
    
    public Category getParentCategory(long key) {
        long parentKey = 
            ((CategoryPlus)categories.get(
                new Long(key))).getCategory().getParent();
        return 
            ((CategoryPlus)categories.get(
                new Long(parentKey))).getCategory();
    }
    
    private void buildCategories(DBConnection dbc) {
        long key = 0;
        ArrayList tempCatList = new ArrayList();
        ArrayList childrenForKey;
        categories = new HashMap();
        Category currentCat;
        currentCat = 
            new Category(0,0,"root");//key 0 is the logical root
        childrenForKey = 
            CategoryDBUtil.getChildCategoriesForKey((long)0,dbc);
        tempCatList.addAll(childrenForKey);
        categories.put(new Long(0), 
                       new CategoryPlus(currentCat, childrenForKey));
        while (!tempCatList.isEmpty()) {
            currentCat = (Category)tempCatList.get(0);
            tempCatList.remove(currentCat);
            childrenForKey = 
                CategoryDBUtil.getChildCategoriesForKey(
                    currentCat.getKey(),dbc);
            if (childrenForKey.isEmpty()) {
                categories.put(
                    new Long(currentCat.getKey()), 
                    new CategoryPlus(currentCat, null));
            } else {
                categories.put(new Long(currentCat.getKey()), 
                    new CategoryPlus(currentCat, childrenForKey));
                tempCatList.addAll(childrenForKey);
            }
        }
    }
    
    //force a rebuild, perhaps scheduled or if table maintenace is done
    public void rebuildCategories(DBConnection dbc) {
        buildCategories(dbc);
    }
    
    class CategoryPlus {
        Category category;
        boolean show;
        ArrayList children;
        ArrayList nullArrayList = new ArrayList();
        
        CategoryPlus(Category categoryIn) {
            category = categoryIn;
            show = true;
        }
        CategoryPlus(Category categoryIn, 
                     boolean showIn) {
            category = categoryIn;
            show = showIn;
        }
        CategoryPlus(Category categoryIn, 
                     ArrayList children) {
            category = categoryIn;
            setChildren(children);
        }
        CategoryPlus(Category categoryIn, 
                     boolean showIn, 
                     ArrayList childrenIn) {
            category = categoryIn;
            show = showIn;
            setChildren(childrenIn);
        }
        
        public Category getCategory() {return category;}
        
        void noShowCategory() {show = false;}
        public boolean getShow() {return show;}
        
        void setChildren(ArrayList childrenIn) {
            if (null == childrenIn) {
                children = nullArrayList;
            } else {
                children = childrenIn;
            }
        }
        public ArrayList getChildren() {return children;}
    }
}