实现圆角矩形边框，hint文字，主要代码： Graphics2D g2d=(Graphics2D) g; g2d.setStroke(new BasicStroke(2,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND)); g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER,0.5f)); g2d.setRend