non va!!!!!!!!!!!!!!!!!!!!
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import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Grafica1 {
private JFrame f;
private Pannello1 p;
private JButton b1;
public Grafica1(){
f=new JFrame("prova pannello");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(300,300);
b1=new JButton("cambia clolore casuale");
f.setLayout(new GridLayout(2,1));
p=new Pannello1();
f.add(b1);
f.add(p);
f.setVisible(true);

}
public class Pannello1 extends JPanel {
public void paintComponet(Graphics g){
Graphics2D g2D=(Graphics2D) g;
int verde=(int) (Math.random()*255);
int rosso=(int) (Math.random()*255);
int blu=(int) (Math.random()*255);
Color colore=new Color(rosso,verde,blu);
g2D.setColor(colore);
g2D.fillOval(0,0,70,70);
}
}
public static void main(String[] args){
Grafica1 g1=new Grafica1();



}

}
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non fa il cerchio prof mi aiuti!!!!!!!!!!!!!!!!!!!!
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