本题用复选框来控制字体的显示，窗口中有一个标签和两个复选按钮，这两个复选按钮分别对应的字体的两个特点：加粗和倾斜，任意选中一个按钮或两个都选中，标签上的字符串就显示对应的字体。
import java. awt. * ;
import java. awt. event. * ;
import javax. swing. * ;
class CheckBoxFrame extends JFrame implements ActionListener
public CheckBoxFrame()
setTitle("CheckBoxTest");
setSize(300,200);
addWindowListener(new WindowAdapter()
public void windowClosing(WindowEvent e)
System. exit(0);

);
JPanel P=new JPanel();
bold=addCheckBox(P,"Bold");
italic=addCheckB0x(P,"Italic");
getContentPane(). add(P."South");
panel=new CheckBoxTestPanel();
getContentPane(). add(panel,"Center");

public JCheckBox addCbeckBox(JPanel p, String name)
JCheckBox c=new JCheckBox(name);
C. addActionListener(______);
P. add(c);
return C;

public void______
int m=(bold. isSelected() Font. BOLD:0)+(italic. isSelected() Font. ITALIC:0);
panel. setFont(m);

private CheckBoxTestPanel panel;
private JCheckBox bold;
private JCheckBox italic;

class CheckBoxTestPanel extends JPanel
public CheckBoxTestPanel()
setFont(Font. PLAIN);

public void setFont(int m)
setFont(new Font("SansSerif", m, 12));
repaint();

public void paintComponent(Graphics g)
super. paintComponent(g);
g. drawstring("The quick brown fox jumps overthe lazy dog.", 0,50);


public class java2
public static void main(String[] args)
JFrame frame=new CheckBoxFrame();
frame. show();