链盘输入选择画出图形问题

求助,本人刚学习JAVA,如果问的问题太菜了,还请各位高手多多包涵.想编一个键盘事件,输入相应的字母C,R,L,就可以相应的由鼠标事件得到相关信息画出"圆形,矩形,直线"但现在我的问题是:怎么能让键盘输入来决定到底画哪种图形.实在想不出来了,还请各位帮忙,先谢过了.
本人没有多少分了,分给的少了,还请见谅.import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Work1216 extends JFrame{
private JLabel label;
private String s="s=";
    private int xvalue1=-10;
    private int yvalue1=-10;
    private int xvalue2=-10;
    private int yvalue2=-10;
    private int lenth=0;
    private Container content;

public Work1216(){
super("Work-12,16");

content=getContentPane();
content.setLayout(new BorderLayout());
label=new JLabel(s);

content.add(label,BorderLayout.SOUTH);


    KeyHandler handler=new KeyHandler();
    addKeyListener(handler);
    
addMouseListener(new MouseAdapter(){
public void mousePressed(MouseEvent e){
xvalue1=e.getX();
yvalue1=e.getY();

}
public void mouseReleased(MouseEvent e){
xvalue2=e.getX();
yvalue2=e.getY();
repaint();
}
});

setSize(500,400);
setVisible(true);

}



public void paint(Graphics g) {


//    g.drawOval(Math.min(xvalue1,xvalue2),Math.min(yvalue1,yvalue2),Math.abs(xvalue2-xvalue1),Math.abs(yvalue2-yvalue1));
//    g.drawLine(xvalue1,yvalue1,xvalue2,yvalue2);

   g.drawRect(Math.min(xvalue1,xvalue2),Math.min(yvalue1,yvalue2),Math.abs(xvalue2-xvalue1),Math.abs(yvalue2-yvalue1));



}
public static void main(String args[]){
Work1216 d=new Work1216();
d.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
}


private class KeyHandler implements KeyListener{
public void keyPressed(KeyEvent e){
s=e.getKeyText(e.getKeyCode());
System.out.println(s);
repaint();
}
public void keyTyped(KeyEvent e){

}
public void keyReleased(KeyEvent e){

}
 
}
}