forked from patniemeyer/learningjava
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathMessageBoard.java
More file actions
29 lines (26 loc) · 824 Bytes
/
Copy pathMessageBoard.java
File metadata and controls
29 lines (26 loc) · 824 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
//file: MessageBoard.java
import java.util.*;
public class MessageBoard extends Observable {
private String message;
public String getMessage( ) {
return message;
}
public void changeMessage( String message ) {
this.message = message;
setChanged( );
notifyObservers( message );
}
public static void main( String [] args ) {
MessageBoard board = new MessageBoard( );
Student bob = new Student( );
Student joe = new Student( );
board.addObserver( bob );
board.addObserver( joe );
board.changeMessage("More Homework!");
}
} // end of class MessageBoard
class Student implements Observer {
public void update(Observable o, Object arg) {
System.out.println( "Message board changed: " + arg );
}
}