controller.java

小型论文管理系统 功能还不是很完善 有待改进

package stumanage;

import stumanage.events.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.io.IOException;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.ResourceBundle;

public class Controller
    extends HttpServlet {

  public HashMap events = new HashMap();
  //Initialize global variables
  public void init() throws ServletException {
    ResourceBundle rd = ResourceBundle.getBundle("Event");
    Enumeration e = rd.getKeys();
    while(e.hasMoreElements()) {
      String key = (String)e.nextElement();
      String value = rd.getString(key);
      try {
        EventHandleBase event = (EventHandleBase)Class.forName(value).newInstance();
        events.put(key,event);
      }
      catch(Exception exc) {}
    }

  }

  public void doGet (
                    HttpServletRequest request,
                    HttpServletResponse response)
   throws ServletException, IOException
 {
   doPost (request, response);
 }

 public void doPost (HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {

   String event = validateEvent (request);

    EventHandleBase handler = getEventHandler (event);

    try {
      handler.process (getServletContext(), request, response);
    } catch (Exception e) {
      request.setAttribute("error", e);
      handler = getEventHandler("REGERROR");
    }

    handler.forward (request, response);

  }



 protected String validateEvent(HttpServletRequest request){
   String e = request.getParameter("event");
   if (e == null || !events.containsKey(e)) {
      e = "REGERROR";
    }
    return e;
}
protected EventHandleBase getEventHandler(String e) {
  EventHandleBase h;
  try {
    h=(EventHandleBase)events.get(e);
    if(h==null) {
      ResourceBundle rd = ResourceBundle.getBundle("Event");
      String value = rd.getString(e);
      h=(EventHandleBase)Class.forName(value).newInstance();
    }
  }catch(Exception exc) { h=(EventHandleBase)events.get("REGERROR");}
  return h;
}


  //Clean up resources
  public void destroy() {
  }
}