java实现截屏

 import java.awt.Dimension;
 import java.awt.Rectangle;
 import java.awt.Robot;
 import java.awt.Toolkit;
 import java.awt.image.BufferedImage;
 import java.io.File;

 import javax.imageio.ImageIO;

 /*******************************************************************
 * 该JavaBean可以直接在其他Java应用程序中调用，实现屏幕的"拍照"
 * This JavaBean is used to snapshot the GUI in a
 * Java application! You can embeded
 * it in to your java application source code, and us
 * it to snapshot the right GUI of the application
 * @see javax.ImageIO
 * @author liluqun ([e-mail])
 * @version 1.0
 *
 *****************************************************/

 public class GuiCamera
 {
     private String fileName; //文件的前缀
     private String defaultName = "GuiCamera";
     static int serialNum=0;
     private String imageFormat; //图像文件的格式
     private String defaultImageFormat="png";
     Dimension d = Toolkit.getDefaultToolkit().getScreenSize();

     /****************************************************************
      * 默认的文件前缀为GuiCamera，文件格式为PNG格式
      * The default construct will use the default
      * Image file surname "GuiCamera",
      * and default image format "png"
      ****************************************************************/
     public GuiCamera() {
       fileName = defaultName;
       imageFormat=defaultImageFormat;

     }

     /****************************************************************
      * @param s the surname of the snapshot file
      * @param format the format of the  image file,
      * it can be "jpg" or "png"
      * 本构造支持JPG和PNG文件的存储
      ****************************************************************/
     public GuiCamera(String s,String format) {

       fileName = s;
       imageFormat=format;
     }

     /****************************************************************
      * 对屏幕进行拍照
      * snapShot the Gui once
      ****************************************************************/
     public void snapShot() {

       try {
       //拷贝屏幕到一个BufferedImage对象screenshot
         BufferedImage screenshot = (new Robot()).createScreenCapture(new
             Rectangle(0, 0, (int) d.getWidth(), (int) d.getHeight()));
         serialNum++;
         //根据文件前缀变量和文件格式变量，自动生成文件名
         String name=fileName+String.valueOf(serialNum)+"."+imageFormat;
         File f = new File(name);
         System.out.print("Save File "+name);
       //将screenshot对象写入图像文件
         ImageIO.write(screenshot, imageFormat, f);
         System.out.print("..Finished!\n");
       }
       catch (Exception ex) {
         System.out.println(ex);
       }
     }

     public static void main(String[] args)
     {
         GuiCamera cam= new GuiCamera("d:\\Hello", "png");//

         cam.snapShot();
     }
 }

原文：http://bbs.chinaunix.net/thread-770968-1-4.html