这里面包含了一百多个JAVA源文件

				When an item is set on the system clipboard, it is possible to be notified when that item is no longer on the clipboard. This is done by including a clipboard owner object when setting the item. 
				    // This class serves as the clipboard owner.
				    class MyClipboardOwner implements ClipboardOwner {
				        // This method is called when this object is no longer
				        // the owner of the item on the system clipboard.
				        public void lostOwnership(Clipboard clipboard, Transferable contents) {
				            // To retrieve the contents, see
				            // e637 Getting and Setting Text on the System Clipboard
				        }
				    }
				
				Here's some code that uses the clipboard owner: 
				    // Create a clipboard owner
				    ClipboardOwner owner = new MyClipboardOwner();
				    
				    // Set a string on the system clipboard and include the owner object
				    StringSelection ss = new StringSelection("A String");
				    Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, owner);