Re: Java compilation error message.



In message <1133213031.701119.288850@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, ri.johnson@xxxxxxxx writes
Attempting to write my first java program that accepts user input.
When I add the listner events to the code it will not compile.  Below
is the code along with the error message:


Code:

import javax.swing.*;
import java.awt.event.*;

public class LottoEvent implements ItemListener, ActionListener,
   Runnable {

}

Compilation Error message:

javac LottoEvent.Java: LottoEvent is not abstract and does not override
abstract method itemStateChanged(java.awt.event.ItemEvent) in
java.awt.event.ItemListener public class LottoEvent implements
ItemListener, ActionListener, Runnable

                                              ^

                                    1 error
Any ideas on how to fix it would be appreciated.


Try

import javax.swing.*;
import java.awt.event.*;

public class LottoEvent implements ItemListener, ActionListener, Runnable {

public void run() {}

public void actionPerformed (ActionEvent evt) {}

public void itemStateChanged(ItemEvent item) {}

}


That error is telling you that you are implementing an interface (or in this case interfaces). Interfaces enforce certain methods, so when you implement the interface you have to implement the methods of the interface. That is why you're getting the errors.


See:

http://java.sun.com/j2se/1.5.0/docs/api/java/awt/event/ItemListener.html

http://java.sun.com/j2se/1.5.0/docs/api/java/awt/event/ActionListener.htm
l

http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Runnable.html


BTW the code you posted does not give the error you claimed, it says this:



C:\JAVA\LottoEvent.java:4: LottoEvent should be declared abstract; it does not define run() in LottoEvent
public class LottoEvent implements ItemListener, ActionListener, Runnable {


I take it that was a typo or mistake ;)




-- Jeffrey Spoon

.



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