提示getOutputStream()已经被调用，怎么解决？谢谢

penknife

我用tomcat4.1服务器，写了这么一段jsp程序，
<%
        response.setContentType("image/jpg";
        ServletOutputStream sos = response.getOutputStream();
        sos.write(file.getBytes(),0,file.length());
%>;
运行时出现以下错误，怎么解决？
Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: getOutputStream() has already been called for this response
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)