java编写的一个java画图程序；工具面板--画笔，直线，圆，矩形，多边形,橡皮，清除；可以调整画笔、橡皮大小；显示画色板，调整画笔颜色；-java write a java drawing program Tools panel- brushes, straight line, circle, rectangle, polygon, eraser, clear can adjust the brush, eraser size display painting swatches to adj