www.pudn.com > JMail4Email.rar > MailControllerServlet.java

package ezmail; 
 
import javax.servlet.*; 
import javax.servlet.http.*; 
 
import java.io.*; 
import java.util.*; 
 
import ezmail.Constants; 
 
/** 
 *  This servlet is the web front component for the ezmail web app.  It expects the following parameter(s): 
 * 
 *  
 
 *    
action - the name of the action to perform
 
 *  
 
 */ 
public class MailControllerServlet extends HttpServlet { 
 
	private HashMap actionTable; 
	private HashMap pageTable; 
 
	/** 
	 *  The method performs the following operations: 
	 * 
	 *  
 
	 *    
  Create the WebAction implementations and place in HashMap 
	 */ 
	public void init() throws ServletException { 
 
		try { 
			log("in the init() method"); 
 
			//  Create the Action implementations and place in HashMap 
			actionTable = new HashMap(); 
			actionTable.put(Constants.LOGIN_KEY, new LoginAction()); 
			actionTable.put(Constants.SEND_MESSAGE_KEY, new SendMessageAction()); 
			actionTable.put(Constants.VIEW_MESSAGE_LIST_KEY, new ViewMessageListAction()); 
			actionTable.put(Constants.VIEW_MESSAGE_DETAIL_KEY, new ViewMessageDetailAction()); 
			actionTable.put(Constants.LOGOUT_KEY, new LogoutAction()); 
 
			//  Setup the destination pages 
			pageTable = new HashMap(); 
			pageTable.put(Constants.LOGIN_KEY, Constants.HOME_PAGE); 
			pageTable.put(Constants.SEND_MESSAGE_KEY, Constants.SEND_MESSAGE_PAGE); 
			pageTable.put(Constants.VIEW_MESSAGE_LIST_KEY, Constants.VIEW_MESSAGE_LIST_PAGE); 
			pageTable.put(Constants.VIEW_MESSAGE_DETAIL_KEY, Constants.VIEW_MESSAGE_DETAIL_PAGE); 
			pageTable.put(Constants.LOGOUT_KEY, Constants.LOGOUT_PAGE); 
		} 
		catch (Exception exc) { 
			exc.printStackTrace(); 
			throw new ServletException(exc.getMessage()); 
		} 
	} 
 
 
	protected void process(HttpServletRequest request, HttpServletResponse response) 
		throws ServletException, IOException { 
 
		try { 
			// retrieve the desired Action implementation 
			String actionParam = request.getParameter(Constants.ACTION_PARAM); 
			Action tempAction = (Action) actionTable.get(actionParam); 
 
			// now let's perform the action! 
			// note:  getServletContext() is inherited from javax.servlet.GenericServlet 
			tempAction.perform(getServletContext(), request, response); 
 
			// Dispatch/forward the request to destination page 
			String destPage = (String) pageTable.get(actionParam); 
 
			System.out.println("destPage = " + destPage); 
 
			ServletContext context = getServletContext(); 
			RequestDispatcher dispatcher = context.getRequestDispatcher(destPage); 
			dispatcher.forward(request, response); 
		} 
		catch (ActionException exc) { 
			exc.printStackTrace(); 
			throw new ServletException(exc.getMessage()); 
		} 
	} 
 
 
	/** 
	 *  Forwards requests to the process(...) method 
	 */ 
    public void doGet (HttpServletRequest request, HttpServletResponse response) 
	  throws ServletException, IOException { 
 
		process(request, response); 
    } 
 
	/** 
	 *  Forwards requests to the process(...) method 
	 */ 
	public void doPost(HttpServletRequest request, HttpServletResponse response) 
		throws ServletException, IOException { 
 
		process(request, response); 
	} 
 
 
}