异常:
java.lang.IllegalStateException: getWriter() has already been called for this response
原因:
response.getWriter()
已经被使用
解决:
ServletOutputStream outputStream = response.getOutputStream();
PrintWriter printWriter = new PrintWriter(outputStream, true);
printWriter.write(form);//直接将完整的表单html输出到页面
printWriter.flush();
if (printWriter != null) {
printWriter.close();
}