这里面包含了一百多个JAVA源文件

				By default, when a tool tip of a component appears, its northwest corner appears at the same x-coordinate as the cursor and 20 pixels lower than the y-coordinate of the cursor. To change this default location for a component, the getToolTipLocation() method of the component must be overridden. 
				    // Set the location of the tool tip such that its nw corner
				    // coincides with the nw corner of the button
				    JButton button = new JButton("My Button") {
				        public Point getToolTipLocation(MouseEvent event) {
				            return new Point(0, 0);
				        }
				    };
				    
				    // Set the location of the tool tip such that its nw corner
				    // coincides with the bottom center of the button
				    button = new JButton("My Button") {
				        public Point getToolTipLocation(MouseEvent event) {
				            return new Point(getWidth()/2, getHeight());
				        }
				    };
				    
				    // Use the default tool tip location
				    button = new JButton("My Button") {
				        public Point getToolTipLocation(MouseEvent event) {
				            return null;
				        }
				    };
				    
				    // Set the tool tip text
				    button.setToolTipText("aString");