redirect와 response객체의 사용

        @RequestMapping(value="/join", method=RequestMethod.POST)
	public ModelAndView join(@ModelAttribute("vo") JoinVO vo, HttpServletResponse response) throws IOException{
		if(commonService.checkEmail(vo.getEmail()).isEmpty()==true){
			response.setContentType("text/html;charset=UTF-8");
			PrintWriter out = response.getWriter();
			out.println("<script>");
			out.println("alert('이미 존재하는 이메일입니다.')");
			out.println("history.back()");
			out.println("</script>");
		}
		
		if(joinService.Join(vo)>=1){
			return new ModelAndView("redirect:/");
		}else{
			return new ModelAndView("redirect:error","code",704); // 회원가입에 문제
		}
		
	}