实现水印效果（1）

    public static void main(String[] args) throws IOException, FontFormatException {
        String name = "d:/Auser/2.png";
        BufferedImage dar = ImageIO.read(new File(name));

        Graphics2D g =dar.createGraphics();
        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP);
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_DEFAULT);
        //写字
        g.setColor(new Color(255,0,0,100));//透明色
        Font font =new Font("宋体",Font.BOLD,60);
        //Font font =Font.createFont(Font.TYPE1_FONT,new File("/a.ttf"));
        font =font.deriveFont(100f);//字体大小
        font = font.deriveFont(Font.BOLD);
        g.setFont(font);

        String text ="123ghjkasda";
        int x=200;
        int y=100;
        g.drawString(text,x,y);

        g.dispose();

        String n1 = name.substring(0,name.lastIndexOf("."));//从零开始节到最后一个点，不包含点
        String n2 = name.substring(name.lastIndexOf("."));//从最后一个点截出来
        String nn =n1 +"_text"+n2;//(123_text.jpg)
        ImageIO.write(dar,"png",new File(nn));//改完后是原名的话就会覆盖

        //执行完打开
        Runtime run =Runtime.getRuntime();
        run.exec("cmd /k start "+ nn);
    }