servlet部署后，如果一次只一个请求是没问题的，如果是两个以上的请求会报：java.net.SocketException:Socket is closed;serlet 代码

public class ImageUrlServlet extends HttpServlet{
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
    }

   
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        ServletOutputStream stream  =response.getOutputStream();
        response.setContentType("image/*");
        byte[] bs=ImageUrlMap.Excute(request.getRequestURI()); 
        if(bs.length!=0)
        {
             stream.write(bs);
        }
        stream .flush();
        stream .close();
    }
   
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }
}

请指教