Spring MVC: java.lang.IllegalStateException: getOutputStream() 已经被这个响应调用

Question

java.lang.IllegalStateException: getOutputStream() has already been called for this response

I am getting above error at return statement. In below two statements in method either one statement is working fine but not both.

public ModelAndView onSubmit(HttpServletRequest request, HttpServletResponse response, Object command, BindException errors) throws Exception {
           ExcelUtils.downloadExcel(response.getOutputStream(), getExportData(command.getFile(), errors));
           return this.showForm(request, response, errors);
}

Here I am trying to download excel file and return to page to display message. Can we can't call response.getOutputStream() and this.showForm(request, response, errors) or return new ModelAndView("redirect:/importPage.do") or return new ModelAndView("forward:/importPage.do") in single flow?

Answer 1

If you have this problem only the second time you export, try adding:

response.getOutputStream().flush();
response.getOutputStream().close();