javaweb servlet验证码加载不出图片


@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        //第一步:在内存中生成width height图片
        int width=100;
        int height=40;
        BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_3BYTE_BGR);
        //第二步:获得图片的画笔，设置颜色，画一个带颜色的矩形
        Graphics g=image.getGraphics();
        g.setColor(Color.pink);
        g.fillRect(0,0,width,height);
        g.setColor(Color.BLACK);
        g.drawRect(0,0,width-1,height-1);
        //第三步:在矩形图片上随机画4个字母或数字
        String s="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        Random ran = new Random();
        g.setFont(new Font("宋体",Font.BOLD,24));
        for (int i = 1; i <=4 ; i++) {
            int index=ran.nextInt(s.length());
            char c=s.charAt(index);
            g.drawString(""+c,width/5*i,height*2/3);
        }
        //第四步:画干扰线
        for (int i = 0; i < 10; i++) {
            int x1=ran.nextInt(width);
            int x2=ran.nextInt(width);
            int y1=ran.nextInt(height);
            int y2=ran.nextInt(height);
            g.drawLine(x1,y1,x2,y2);
        }
        //第五步:把这个图片写到response中
        ImageIO.write(image,"jpg",resp.getOutputStream());
    }
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }

F12看下前端网页控制台报什么错

F12打开浏览器控制台，切换到network，刷新页面，查看请求。

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