Java程序设计作业3

ultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);}}15.7编写一个程序显示一个圆的颜色,当按下鼠标键时颜色为黑色,释放鼠标垫时颜色为白色importjava.awt.BorderLayout;importjava.awt.Color;importjava.awt.event.MouseEvent;importjava.awt.event.MouseListener;importjavax.swing.JFrame;importjavax.swing.JPanel;lassB{?/**?*@paramargs?*/?publicstaticvoidmain(String[]args){ JFramef=newJFrame(); finalJPanelp=newJPanel(); f.add(p,BorderLayout.CENTER); p.addMouseListener(newMouseListener(){ publicvoidmouseClicked(MouseEvente){} publicvoidmouseEntered(MouseEvente){} publicvoidmouseExited(MouseEvente){} publicvoidmousePressed(MouseEvente){ p.setBackground(Color.black); } publicvoidmouseReleased(MouseEvente){ p.setBackground(Color.white); } }); f.setSize(200,300); f.setVisible(true); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);?}}