Timer

[Antony Amicone]

why it does not run?it only write "try main"

  import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class Ex4 {
private int i = 0;
private Timer t;

public void prova() {
t = new Timer(1000,new ActionListener(){
public void actionPerformed(ActionEvent e){
System.out.println("try this");
System.out.println(i);
i++;
}});
t.start();
}

public static void main(String[] args) {
new Ex4().prova();
System.out.println("try main");
}
 
}
  

[ March 30, 2006: Message edited by: Antony Amicone ]

[Jeff Albertson]

Havin' a wee spot o' fun?

[Antony Amicone]

i'm trying to figure out how to use timers...

[Keith Lynn]

The main method is exiting before the timer has a chance to do anything. Add a delay at the end of the main method, and also remember that Frame's aren't visible by default.
[ March 30, 2006: Message edited by: Keith Lynn ]

[Antony Amicone]

how to add delay at the and of main? if i put the start of timer in the method prova it is not runned anyway

[Keith Lynn]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class Ex4 {
private int i = 0;
private Timer t;
private JFrame f;

public void prova() {
t = new Timer(1000,new ActionListener(){
public void actionPerformed(ActionEvent e){
f = new JFrame();
f.setBounds(100,100,100,100);
System.out.println("try this");
System.out.println(i);
i++;
}});
t.start();
}

public static void main(String[] args) {
new Ex4().prova();
System.out.println("try main");
 
                try {
                   Thread.sleep(2000);
                } catch (InterruptedException ie) {
                }
}
 
}

[Antony Amicone]

tnx a lot, is it impossible without thread?

[Keith Lynn]

Well if you had other activities happening in the main method, that would work too. The problem is that you set the timer so that the actionPerformed method is called every second. When you create the timer, that does not stop the main method from executing. It goes to the next line, and then it is finished. So the main method exits before the first second.

Note that using Thread.sleep does not create a new thread. There is a thread that is running the main method. Whatever thread executes Thread.sleep is the one that will pause.
[ March 30, 2006: Message edited by: Keith Lynn ]

[Antony Amicone]

tnx a lot, u were really gentle, and exhaustive