在用 Java 2D 进行画图时可以非常方便的设置线条的粗细及接头的形状。下面是一个简单的例子供大家参考：
float thick = 0.5f; //设置画刷的粗细为 0.5
BufferedImage bi = new BufferedImage(800, 600, BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D)bi.getGraphics();
Stroke stroke = g.getStroke(); //得到当前的画刷
g.setStroke(new BasicStroke(thick, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_ROUND)); //设置新的画刷
g.draw(new Line2D.Float(x1, y1, x2, y2)); 画线
g.setStroke( stroke ); //将画刷复原
