package cylikon.YahooEnt; 

import javax.servlet.*; 
import javax.servlet.http.*; 
//import javax.ejb.FinderException; 
//import javax.ejb.CreateException; 
import javax.naming.*; 
import java.rmi.RemoteException; 
import java.util.Properties; 
import java.sql.*; 
import sun.jdbc.rowset.CachedRowSet; 
import java.io.*; 

public class YahooEntServlet extends HttpServlet     			{ 

public static String catName[]= {"NYC","HipHop","Lesbian Gay","Technical Playground","My Resume","Site Search","Maintenance"}; 

public static String catNo[]={"2","3","5","52","51","8","75"}; 
Thread thr=null; 

//let's create the Entity Beans during servlet initialization...
// the CachedRowSets created during ejbCreate will be bound to a JNDI namespace

public void init(ServletConfig config) throws ServletException { 
	super.init(config); 
        int i=0; 

  try { 
        Context ctx=getInitialContext(); 
        CategoryHome home = (CategoryHome) ctx.lookup("YahooEnt");
        while (i< catName.length)	 { 
        Category cat= home.create(catNo[i],catName[i]); 
        System.out.println("EJB "+catName[i]+" was created."); 
        int ready=cat.crsReady(); 
        String crserror = cat.crsError(); 
          if (ready==1) { 
            System.out.println("CachedRowSet for "+catName[i]+" is ready."); 
            CachedRowSet crs=cat.crs(); 
               //bind the CachedRowSet to the JNDI namespace
           ctx.rebind(catName[i],crs); 
			} //end if
                           else   { //report the error

          System.out.println("An ERROR occurred with the CachedRowSet for "+catName[i]+"."); 
          System.out.println("The error from crsError was: "+crserror); 
          System.out.println("CachedRowSet could not be bound to the JNDI namespace."); 
				  } //end else
        i++;  //increment i
				 	 } //end while

      } catch (Throwable t) { System.out.println("ERROR initializing servlet: "+t+" "+t.getMessage());  }  //end try-catch
          
// Now, start the CRUpdater thread (thr)....
   try     { 
      thr=new Thread(new CRUpdater()); 
      thr.start(); 

           } catch (Throwable t) { System.out.println("ERROR with the new Thread thr: "+t.getMessage());  } 
							   } // end init method

// ********* Servlet doGet method **********************
public void doGet(HttpServletRequest req,HttpServletResponse res) 
	throws ServletException, IOException   				{

  PrintWriter out =res.getWriter(); 
  String category=req.getParameter("cat"); 
  
  // if category is null, we will be listing all available CachedRowSets bound to JNDI, 
  // otherwise, we will only list the requested category.
  
  if (category==null)    	            { // we are list ALL available CachedRowSets..
     
     Context ctx=getInitialContext(); 
     int i=0; 
     while(i<catName.length) { 
       try {             
          CachedRowSet cr= (CachedRowSet) ctx.lookup(catName[i]); 
            // print the number & name of the category and the number of rows in cr
          out.print("<b>Category "+catNo[i]+": "+catName[i]+"</b> ("+cr.size()+")<br>"); 
          out.flush(); 

          while (cr.next())  {  // let's just print out links from the CachedRowSet, fields 3&4
          out.print("<a href='"+cr.getString(4).trim()+"'>"+cr.getString(3).trim()+"</a><br>"); 
			     } //end while

           } catch (Throwable t) { out.println("CachedRowSet for "+catName[i]+" not found in the JNDI namespace.<br>The error was: "+t.getMessage());  } //end catch
     out.print("<br><hr>"); 
     out.flush(); 
     i++;  
 			     } //end while


				            }  //end if

                                               else  {  
   		out.print("Feature not ready yet!"); 
						     } //noting yet

									} //end doGet





// ********* Servlet Destroy method **********************

public void destroy()  				   {

// we need to remove all EJBs created and unbind the cached rowsets from the JNDI namespaces
     Context ctx=null; 
     CategoryHome home=null; 
     int i=0; 

// first, let's stop the CRUpdater thread (thr).....
try { 
   System.out.println("Attempting to stop CRUpdater thread..."); 
   if (thr !=null)   { 
     if (thr.isAlive())  {           
        thr.interrupt(); 
        thr.join(); 
                        } //end if 
                     } //end if
    } catch (Throwable t) { System.out.println("ERROR stopping thread thr: "+t.getMessage()); } 

try { 
   if (!thr.isAlive()) { System.out.println("CRUpdater thread stopped.");  } else {    System.out.println("CRUpdater thread is still running!");  }
   } catch (Throwable t) { System.out.println("Unknown ERROR: "+t.getMessage());  }
 
  try { 
   ctx=getInitialContext(); 
   home = (CategoryHome) ctx.lookup("YahooEnt"); 
      } catch (Throwable t) { System.out.println("\nERROR in servlet destroy method: "+t+" "+t.getMessage());    }  //end try-catch   


  try { 
      while (i<catName.length)         { 
            ctx.unbind(catName[i]);  //unbind from the JNDI namespace
            System.out.println(catName[i]+" unbound from the JNDI namespace."); 

            i++; //increment i
   				        } //end while
      } catch (Throwable t) { System.out.println("\nERROR in servlet destroy method: "+t+" "+t.getMessage());    }  //end try-catch  


      i=0; 
      while (i<catName.length)          { 
  try { 

            //Category cat=home.findByPrimaryKey(catNo[i]); 
            home.remove(catNo[i]);  //call overloaded ejbRemove method 
            System.out.println("EJB "+catName[i]+" removed."); 

             i++; //increment i
      } catch (Throwable t) { System.out.println("\nERROR in servlet destroy method: "+t+" "+t.getMessage());  break;  }  //end try-catch  

   				        } //end while

  
						} //end destroy method



// Initial Contexts for EJB lookups...
public static Context getInitialContext()  { 
        Context c=null; 
        try{ 
        Properties p=new Properties(); 
        p.put(Context.INITIAL_CONTEXT_FACTORY,"org.jnp.interfaces.NamingContextFactory"); 
        c=new InitialContext(p); 
          } catch (Throwable t) { System.out.println("ERROR getting Initial Context: "+t+"  "+t.getMessage()+"\nMaybe the factory went on strike <shrug>.");  }//end try-catch

          return c;                      
				    } //end getInitialContext


									} //end class

////////// Runnable class for updating the cached rowsets and jndi namespaces /////////

class CRUpdater implements Runnable                          { 
   String names[] = YahooEntServlet.catName;
   String numbers[] = YahooEntServlet.catNo; 
   Context cx=null; 
   int i; 
   Category cat=null; 
   CategoryHome home=null; 
   CachedRowSet cr=null; 

  public CRUpdater() { }  //super class

  public void run()                         {

    while (true)  {
       i=0; 
 
       try{ 
              Thread.sleep(240000); //take breaks between cached row refreshment-4 minutes here

           } catch (InterruptedException ie) { System.out.println("Thread interrupted: "+ie.getMessage());  break; } 

       System.out.println("Updating and rebinding CachedRowSets for YahooEnt..."); 

       try { 
          cx=YahooEntServlet.getInitialContext(); 
          home=(CategoryHome) cx.lookup("YahooEnt"); 
           } catch (Throwable t) { System.out.println("ERROR looking up YahooEnt: "+t.getMessage());  break; } 


           while (i<names.length)   {

                 try{
             cat=home.findByPrimaryKey(numbers[i]); 
             System.out.println("Found EJB for category "+numbers[i]+","+names[i]); 
                   } catch (Throwable t) { System.out.println("ERROR looking up "+names[i]+": "+t.getMessage());  break; } 

             // tell the EJB to repopulate the cached rowset with fresh data...
               try { 
             cat.PopulateRowSet(); 
             System.out.println("CachedRowSet for "+names[i]+" repopulated."); 
                  } catch (Throwable t) { System.out.println("ERROR repopulating rowset for "+names[i]+": "+t.getMessage());  break; } 

             // grab the updated CachedRowSet...
                 try { 
             cr=cat.crs(); 
             //rebind the new cached rowset to the JNDI namespace...
             cx.rebind(names[i],cr); 
             System.out.println("New CachedRowSet for "+names[i]+" rebound to JNDI namespace."); 
                   } catch (Throwable t) { System.out.println("ERROR binding "+names[i]+" to the JNDI namespace: "+t.getMessage());  break; } 

			
                     i++; //increment
				    } //end while

		  } //end while true

			                     } //end run method


							     } //end class