声明：
   本文核心代码选择自langzi84的blog请看以下链接
http://dev.csdn.net/article/44/article/44/44529.shtm
http://blog.csdn.net/langzi84/archive/2004/10/21/146331.aspx

   代码1。在屏幕上输出当前鼠标所在的屏幕颜色。

import java.awt.*;
public class PickColor {
public static void main(String[] args) {
PickColor pc = new PickColor();
Color color = pc.pickColor();
System.out.println("color = "+color);
}
public Color pickColor() {
Color pixel = new Color(0,0,0);
Robot robot = null;
Point mousepoint;
int R,G,B;
// MouseInfo mouseinfo = new MouseInfo();
try {
robot = new Robot();
} catch (AWTException e) {
e.printStackTrace();
System.exit(1);
}
mousepoint = MouseInfo.getPointerInfo().getLocation();
pixel = robot.getPixelColor(mousepoint.x,mousepoint.y);
R = pixel.getRed();
G = pixel.getGreen();
return pixel;
}
}

   代码2。使用一个GUI，输出当前鼠标所在的屏幕颜色，并改变GUI的背景色。
// create by kin 2004/10/24 refer to http://dev.csdn.net/article/44/44529.shtm

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class PickColor2 extends JFrame {
public static void main(String[] args) {
PickColor2 pc = new PickColor2();
//Color color = pc.pickColor();
//System.out.println("color = "+color);
}
public PickColor2 () {
super("Pick Color");
setSize(200,200);
JPanel p =new JPanel();
getContentPane().add(p);
// this mouse listener only is limited in the java desktop region
p.addMouseMotionListener(new PickColorMouesMotionListener(p));
// this thread is really effected!
new PickColorThread(p).start();
setVisible(true);
}
/**Mouse Motion Listener,when mouse are moving, then set corresping screens color to the JPanels background Color. */
class PickColorMouesMotionListener extends MouseMotionAdapter {
private JPanel p = null;
PickColorMouesMotionListener(JPanel p) {
this.p = p;
}
public void mouseMoved(MouseEvent e) {
Color c = pickColor();
this.p.setBackground(c);
//System.out.println (c);
}
}
class PickColorThread extends Thread {
private JPanel p = null;
PickColorThread(JPanel p){
this.p=p;
}
public void run () {
while (true) {
try {
Thread.currentThread().sleep(10);
Color c = pickColor();
this.p.setBackground(c);
// try change the foreground when background s r <= 50 or g <= 50 or b <= 50
Graphics g = p.getGraphics ();
if (c.getRed() <=50 || c.getGreen() <= 50 || c.getBlue() <= 50) {
g.setColor(Color.WHITE);
} else {
g.setColor(Color.BLACK);
}
g.drawString(c.toString(),0,100);
g = null;

//System.out.println (c);
} catch (InterruptedException e) {
e.printStackTrace();
System.exit(1);
}
}
}
}
/**Get Screen Color*/
public Color pickColor() {
Color pixel = new Color(0,0,0);
Robot robot = null;
Point mousepoint;
int R,G,B;
// MouseInfo mouseinfo = new MouseInfo();
try {
robot = new Robot();
} catch (AWTException e) {
e.printStackTrace();
System.exit(1);
}
mousepoint = MouseInfo.getPointerInfo().getLocation();
pixel = robot.getPixelColor(mousepoint.x,mousepoint.y);
R = pixel.getRed();
G = pixel.getGreen();
return pixel;
}
}