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 (liluqun@263.net)
* @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 st