HttpServletPortletResponseWrapper.java 文件源码

@Override
public ServletOutputStream getOutputStream() throws IOException {
   if (servletOutputStream == null) {
      outputStream = (portletResponse instanceof MimeResponse) ? ((MimeResponse) portletResponse)
            .getPortletOutputStream() : DummyServletOutputStream.getInstance();
      if (outputStream instanceof ServletOutputStream) {
         servletOutputStream = (ServletOutputStream) outputStream;
      } else {
         servletOutputStream = new ServletOutputStream() {
            @Override
            public void write(int b) throws IOException {
               outputStream.write(b);
            }

            @Override
            public boolean isReady() {
               // Servlet 3.1 API. Not implemented.
               return true;
            }

            @Override
            public void setWriteListener(WriteListener arg0) {
               // Servlet 3.1 API. Not implemented.
            }
         };
      }
   }
   return servletOutputStream;
}