Change url URLConnection

Question

I want to connect from an applet to a servlet with URLConnection. There are 2 ways to connect: in the beginning of each session you connect to the applet to get a list of drawn shapes. I create an URLConnection object and connect to the servlet. I go into the doGet-method, retrieve the values from a database and returns an arraylist. I use the doPost method to save new shapes.
When i delete a shape from the canvas, i want to return to the doGet method by adding a parameter to the url. E.g ../ShapeServlet?shapeid=20. The problem is, the url is correct, but the URLConnection object keeps using the url from the beginning of the session (without the parameter). I use 2 seperate objects so it's kinda weird he keeps connecting to the servlet with the first url. I also tried to do it hard-coded, but it doesn't work either.
Here's the code:
Load the shapes from the applet:
     public ArrayList loadShapes()
          ObjectInputStream inputFromServlet = null;
          try{
               URL servlet = new URL(url);
               URLConnection con = servlet.openConnection();
               con.setUseCaches(false);
               inputFromServlet = new ObjectInputStream(con.getInputStream());
               ArrayList lijst = (ArrayList) inputFromServlet.readObject();
               inputFromServlet.close();
               return lijst;
          catch(MalformedURLException e){ e.printStackTrace(); }
          catch(IOException e){ e.printStackTrace(); }
          catch(ClassNotFoundException e){ e.printStackTrace(); }
          return null;
     }Delete a shape:
     /** Shape weggooien */
     public void deleteShape(int shapeid)
          try{
               String a = "http://PCPST2:8080/AppletViewer/ShapeServlet?shapeid=" + shapeid;
               URL servlet = new URL(a);
               System.out.println("DELETESHAPE: " + a);
               URLConnection connectionTwo = servlet.openConnection();               
               connectionTwo.setUseCaches(false);               
          catch(MalformedURLException e){ e.printStackTrace(); }
          catch(IOException e){ e.printStackTrace(); }
     }

Answer 1

it seems that deleteShape() doesn't connect to the servlet. Is it possible that >the servlet rejects the connection?No, he simply doesnt connect :), wierd behaviour, but that's how the default implementation of URLConnection and HttpURLConnection works.
The following is from javadocs
The connection object is created by invoking the openConnection method on a URL.
The setup parameters and general request properties are manipulated.
The actual connection to the remote object is made, using the connect method.
The remote object becomes available. The header fields and the contents of the remote object can be accessed.
You havent used the connect() method in your deleteShapes() method.
Hang on, even if you use it, it wouldnt connect to the Servlet.
I did some reading up on this and again javadcos has this to say about the connect() method
Operations that depend on being connected, like getContentLength, will implicitly perform the connection, if necessary.
So what I did was forced connect() by getting the input stream from the connection.
In your code, though the deleteShapes() method doesnt have anything to read from the Servlet, create a reader and make a dummy readLine() call.
You would see that it connects now. Add the code below to your deleteShapes() method.
        InputStreamReader reader = new InputStreamReader(conn.getInputStream());       
        System.out.println((new BufferedReader(reader)).readLine());
         //this will return null, coz there's nothing to be read, and
         //yet it would ensure connection.Hope this helps,
ram.