Observer/Observable

[Andy Rayner]

Hello im having a few problems using the Observer Observable,
I have these classes so far

Model - kicks off two threads for input and output
Input - input from the keyboard
Output - output from the server
ViewClass - the GUI

at the moment in the output i use a bufferreader which gets each character the server gives and outputs it to the terminal, i am wanting to display this in a JTextArea using the observable
so i do this in the Output class

  
System.out.print(c); 
String s = Character.toString(c);
m.setText(s);

c is a char which holds a character representation of the int fromServer.read() //from server been the bufferreader
i then convert the char into a string and send it to a method in the Model(m) called set text.

in the model i have

class Model extends Observable
// i extend the observable
 
theView = new ViewClassGUI(this);
addObserver(theView);
//in the constructor i have these two lines.
 
//in the setText method i have this
public void setText(String s)
{
text = s;
setChanged();
notifyObservers();

}
 
//in the viewclass i implement Observer
public class ViewClass extends JFrame implements Observer
 
//and here is my update method
public void update (Observable obs, Object obj) 
{
      System.out.println("update");
      if (obs == callingModel) {
          jTextArea1.setText(callingModel.getText());
      }//end if
}
 

  

for some reason i am getting this error message

----jGRASP exec: java Harness

java.lang.NoSuchMethodError
at OutputStream.run(OutputStream.java:37)

----jGRASP: operation complete.

Hope you can help me with this
many thanks again
Andy

[Layne Lund]

The error message indicates that the problem occurs on line 37 of OutputStream.java. Is this your own class called OutputStream or is it the OutputStream from the standard Java IO package?

Layne

[Dale Seng]

I'm not so sure I'd call spinning off threads a beginner question.

But for sure, you would need to post more than snipets to get an answer, like maybe identify line 37 of your failing code (assuming that is your code and not from the IO package).

--Dale--