java 获取剪贴板内容出现问题

Question

通过Swing执行时，获取不到系统剪贴板的内容，如果写成java 的main 方法不通过Swing执行，可以获取剪贴板的内容，这是怎么回事？怎么解决？

Answer 1

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.io.IOException;

public class ClipboradOperate {
/**@Description:
* @author zhk
* @createtime 2012-7-12 上午11:33:06
* @param args
*/
public static void main(String[] args) {
Clipboard clip = Toolkit.getDefaultToolkit().getSystemClipboard();//获取系统剪贴板

try {
ImageViewer im=new ImageViewer(getImageFromClipboard());
}catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 从指定的剪切板中获取文本内容
* 本地剪切板使用 Clipborad cp = new Clipboard("clip1"); 来构造
* 系统剪切板使用 Clipboard sysc = Toolkit.getDefaultToolkit().getSystemClipboard();
* 剪切板的内容 getContents(null); 返回Transferable
*/
protected static String getClipboardText() throws Exception{
Clipboard clip = Toolkit.getDefaultToolkit().getSystemClipboard();//获取系统剪贴板
// 获取剪切板中的内容
Transferable clipT = clip.getContents(null);
if (clipT != null) {
// 检查内容是否是文本类型
if (clipT.isDataFlavorSupported(DataFlavor.stringFlavor))
return (String)clipT.getTransferData(DataFlavor.stringFlavor);
}
return null;
}

//往剪切板写文本数据
protected static void setClipboardText(Clipboard clip, String writeMe) {
Transferable tText = new StringSelection(writeMe);
clip.setContents(tText, null);
}

// 从剪切板读取图像
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;
}
// 写图像到剪切板
protected static void setClipboardImage2(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);
}

}

ImageViewer.java
/*
* 查看图形的窗口
*/
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
/**
* 用于显示图形的窗口
*/
public class ImageViewer extends Frame {
private Image image;
/**
* 显示一个图像
* @param viewMe
*/
public ImageViewer(Image viewMe) {
image = viewMe;
MediaTracker mediaTracker = new MediaTracker(this);
mediaTracker.addImage(image, 0);
try {
mediaTracker.waitForID(0);
} catch (InterruptedException ie) {
ie.printStackTrace();
System.exit(1);
}
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
//窗口适应图像大小
setSize(image.getWidth(null), image.getHeight(null));
//窗口标题
setTitle("Viewing Image from Clipboard");
setVisible(true);
}
public void paint(Graphics graphics) {
graphics.drawImage(image, 0, 0, null);
}
/**
* 用于读取图像文件并生成Image对象
*/
public static Image getImageFromFile(String fileName) {
Toolkit toolkit = Toolkit.getDefaultToolkit();
Image image = toolkit.getImage(fileName);
return image;
}
}

Answer 2

把代码贴出来看看