getWriter() has already been called
- Java code
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); out.print( " <script> alert( 'Booking successfully ') </script> "); ByteArrayOutputStream out1 = QRCode.from(all).to(ImageType.PNG).stream(); response.setContentType("image/png"); response.setContentLength(out1.size()); OutputStream outStream = response.getOutputStream(); outStream.write(out1.toByteArray()); outStream.flush(); outStream.close();上看,只能用其中一.但是我想用2. 怎做. 另外,我加out.clear() 和out = pageContext.pushBody(); 就出.cannot find symbol.
[解决办法]
你是想显示图片吧。直接<img src="ImgServlet" />获取图片。也就是图片另外用个servlet。