clipboardhelper.java

一个用Java 造成的小画家

package onlyfun.caterpillar.image;

import java.awt.Image;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.IOException;

import javax.swing.JOptionPane;

public class ClipboardHelper {
    public static void imageToClipboard(Transferable transferableImage) {
        Toolkit
        .getDefaultToolkit()
        .getSystemClipboard()
        .setContents(transferableImage, null);
    }
    
    public static Image getImageFromClipboard() {
        // get the system clipboard
        Clipboard systemClipboard =
          Toolkit
          .getDefaultToolkit()
          .getSystemClipboard();
        
        // get the contents on the clipboard in a 
        // Transferable object
        Transferable clipboardContents =
          systemClipboard
          .getContents(null);
        
        // check if contents are empty, if so, return null
        if(clipboardContents == null) {
            return null;
        }
        else {
            try {
                // make sure content on clipboard is 
                // falls under a format supported by the 
                // imageFlavor Flavor
                if(clipboardContents.isDataFlavorSupported(
                    DataFlavor.imageFlavor)) {
                    // convert the Transferable object
                    // to an Image object
                    Image image =
                      (Image) clipboardContents
                              .getTransferData(DataFlavor.imageFlavor);
                    return image;
                }
            } 
            catch (UnsupportedFlavorException e) {
                JOptionPane.showMessageDialog(null, e.getMessage(),
                        "Info.", JOptionPane.INFORMATION_MESSAGE);
            } 
            catch (IOException e) {
                JOptionPane.showMessageDialog(null, e.getMessage(),
                        "Info.", JOptionPane.INFORMATION_MESSAGE);
            }
        }
        
        return null;
    }
}