thread safety check

[John Schretz]

I have been trying to implement some practices and good framework for maintaining future code in my servlets, that i have been using in core java.
I feel that i have done everything right to keep the servlet thread safe. Just looking for a second opinion. Always parinoid about locking threads.

Thanks
John

package admin;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import utils.OrderedKeyMap;
import adminEcom.EditOrder;
import adminEcom.EditOrderItems;

public class RevolvingItemsController extends HttpServlet {

	private static OrderedKeyMap<IValidProcessor, IProcessor> processors = new OrderedKeyMap<IValidProcessor, IProcessor>(10);
	private static String[] buttonList = new String[]{"searchItems.x","addItem.x","saveItem.x","saveBrand.x","saveNew.x","update.x","chooseItem.x",};

	public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
	{
		for ( int i = 0, n = buttonList.length; i < n; i ++){ 
			process(request.getParameter(buttonList[i]), request, request.getSession());
		}
		response.sendRedirect("revolvingItemsView");
	}

	static{
		processors.put(new ICProcessSearchItems(), new IProcessor(){ //Process Search
			public void process(HttpServletRequest request, HttpSession session) {
				searchItem(request, session);
			}});
		processors.put(new ICProcessAddItems(), new IProcessor(){ //Process add item
			public void process(HttpServletRequest request, HttpSession session) {
				addItem(request, session);
			}});
		processors.put(new ICProcessRemoveItems(), new IProcessor(){ //Process remove item
			public void process(HttpServletRequest request, HttpSession session) {
				removeItem(request, session);
			}});
	}

	public static void process(String field, HttpServletRequest request, HttpSession session){ 
		for ( int i = 0, n = processors.size(); i < n; i ++){ 
			IValidProcessor condition = processors.getKey(i); 
			if ( condition.isValid(field, request)){ 
				processors.get(condition).process(request, session); 
			} 
		} 
	} 

	protected static void addItem(HttpServletRequest request, HttpSession session) {
		
	}

	protected static void searchItem(HttpServletRequest request, HttpSession session) {
		
	}
	
	protected static void removeItem(HttpServletRequest request, HttpSession session) {
		ArrayList<EditOrderItems> itemsToRemove = null;
		EditOrder order = (EditOrder) session.getAttribute("editOrd");

		Enumeration<String> keys = request.getParameterNames();
		while ( keys.hasMoreElements() )
		{
			String key = keys.nextElement();
			String itemNum = key.substring(key.indexOf("_") +1);

			String[] valueArray = request.getParameterValues(key);

			for ( int i = 0, n = valueArray.length; i < n; i ++){ 
				if(valueArray[i].equalsIgnoreCase("on")){
					itemsToRemove = order.getEditItems();
					for (int a = 0; a < itemsToRemove.size(); a++)
					{
						EditOrderItems lineItem = itemsToRemove.get(a);
						if(lineItem.getItemNum() == Integer.parseInt(itemNum)){
							itemsToRemove.remove(a);
						}
					}
				}
			}
		}
		order.setEditItems(itemsToRemove);
		//order = calculateTotals(order, session);
		session.setAttribute("editOrd", order);
		session.setAttribute("EdItems", null);
	}

	public static interface IProcessor {
		public void process(HttpServletRequest request, HttpSession session);
	}

	public static interface IValidProcessor {
		public boolean isValid(String process, HttpServletRequest request);
	}

	public static class ICProcessSearchItems implements IValidProcessor{
		public boolean isValid(String field, HttpServletRequest request) {
			return field != null;
		}		
	}

	public static class ICProcessAddItems implements IValidProcessor{
		public boolean isValid(String field, HttpServletRequest request) { 
			return field != null; 
		}
	} 
	
	public static class ICProcessRemoveItems implements IValidProcessor{
		public boolean isValid(String field, HttpServletRequest request) { 
			return field != null; 
		}
	} 
}

[Christophe Verré]

removeItem removes items from an order which comes from the session. There may cause an ArrayIndexOutOfBounds at itemsToRemove.remove(a);

[John Schretz]

Christophe Verré wrote:removeItem removes items from an order which comes from the session. There may cause an ArrayIndexOutOfBounds at itemsToRemove.remove(a);

More of a null pointer i would assume
if EditOrderItems lineItem = itemsToRemove.get(a) has a valid value, itemsToRemove.remove(a); should not thow an out of bounds exception if im not mistaken.
Does the thread safety look ok?

thanks
john

EDIT: I see now what you were talking about: itemsToRemove = order.getEditItems();
Good catch. I will take cae of that too.

   
					for (int a = 0; a < itemsToRemove.size(); a++)
					{
						EditOrderItems lineItem = itemsToRemove.get(a);
						if(lineItem != null && lineItem.getItemNum() == Integer.parseInt(itemNum)){ // added check here
							itemsToRemove.remove(a);
						}
					}