问答题

程序如下：
∥Java_2. java
import java. awt. *;
import java. awt. event. * ;
∥********** Found **********
public class Java_2 (5) Frame implements ActionListener{
public static void main( String args[ ]){
Java_2 fr=new Java_2("Hello!");
fr. setLayout(new FlowLayout( ));
fr. setSize (200,100);
fr. setBackground(Color. blue);
Button b=new Button("确定");
∥********** Found **********
b. ( 6 ) (new Java._2( ));
fr..add(b);
fr. setVisible (true);
}
public void actionPerformed( ActionEvent e){
System. exit(0);
}
public Java_2(String str){
super(str);
}
public Java_2( ){
}
}