如题
要求可以用鼠标拖动截图区大小和显示截图区预览
鼠标双击后截取图片存储到指定文件夹
------解决方案--------------------
首先用js来确定截取的图片的范围，给整个图片和截取范围信息传递给jsp程序，通过Java来截取
js确定截取图片的代码：http://topic.csdn.net/u/20080806/02/B295D4E4-C98F-4621-9835-B7D915B4952D.html
然后通过java来截取对应的图片即可完成楼主的功能！
------解决方案--------------------
java截图
- Java code
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 ([email]liluqun@263.net[/email]) * @version 1.0 * ******************************************************************************/ 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 //这里 createScreenCapture中的4个参数就是需要截取的图形的2个顶点，也就是通过js确定的2个点 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! "); } catch (Exception ex) { System.out.println(ex); } } public static void main(String[] args) { GuiCamera cam = new GuiCamera("Test", "png"); cam.snapShot(); } }