java读取粘贴板内容——将图片转成png或者jpg格式

java读取粘贴板的内容，讲图片转成png或者jpg,转换jpg后背景图片会变化，png没有问题

代码如下：转载自：http://blog.csdn.net/myfmyfmyfmyf/article/details/17095261

package com;

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class Test {
    public static void main(String[] args) {
        
        try {
            //获取粘贴板图片
            Image image = Test.getImageFromClipboard();
            File file= new File("D:\\a.png");
            //转成jpg
            //BufferedImage bufferedImage = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_RGB);
            //转成png
            BufferedImage bufferedImage = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_ARGB);
            Graphics2D g = bufferedImage.createGraphics();
            g.drawImage(image, null, null);
            //ImageIO.write((RenderedImage)bufferedImage, "jpg", file);
            ImageIO.write((RenderedImage)bufferedImage, "png", file);

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    
    /**
     * 从剪切板获得文字。
     */
    public static String getSysClipboardText() {
        String ret = "";
        Clipboard sysClip = Toolkit.getDefaultToolkit().getSystemClipboard();
        // 获取剪切板中的内容
        Transferable clipTf = sysClip.getContents(null);
        
        if (clipTf != null) {
            // 检查内容是否是文本类型
            if (clipTf.isDataFlavorSupported(DataFlavor.stringFlavor)) {
                try {
                    ret = (String) clipTf
                            .getTransferData(DataFlavor.stringFlavor);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }

        return ret;
    }

    /**
     * 将字符串复制到剪切板。
     */
    public static void setSysClipboardText(String writeMe) {
        Clipboard clip = Toolkit.getDefaultToolkit().getSystemClipboard();
        Transferable tText = new StringSelection(writeMe);
        clip.setContents(tText, null);
    }

    /**
     * 从剪切板获得图片。
     */
    public static Image getImageFromClipboard() throws Exception {
        Clipboard sysc = Toolkit.getDefaultToolkit().getSystemClipboard();
        Transferable cc = sysc.getContents(null);
        if (cc == null)
            return null;
        else if (cc.isDataFlavorSupported(DataFlavor.imageFlavor))
            return (Image) cc.getTransferData(DataFlavor.imageFlavor);
        return null;
    }

    /**
     * 复制图片到剪切板。
     */
    public static void setClipboardImage(final Image image) {
        Transferable trans = new Transferable() {
            public DataFlavor[] getTransferDataFlavors() {
                return new DataFlavor[] { DataFlavor.imageFlavor };
            }

            public boolean isDataFlavorSupported(DataFlavor flavor) {
                return DataFlavor.imageFlavor.equals(flavor);
            }

            public Object getTransferData(DataFlavor flavor)
                    throws UnsupportedFlavorException, IOException {
                if (isDataFlavorSupported(flavor))
                    return image;
                throw new UnsupportedFlavorException(flavor);
            }

        };
        Toolkit.getDefaultToolkit().getSystemClipboard().setContents(trans,
                null);
    }
}