#05. BE - 쿠키를 이용한 상태정보 유지하기

<5. 쿠키를 이용한 상태정보 유지하기>

참고: [boostcourse full-stack] http://www.edwith.org/boostcourse-web

package kr.or.connect.guestbook.controller;
 
import java.util.ArrayList;
import java.util.List;
 
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
 
import kr.or.connect.guestbook.dto.Guestbook;
import kr.or.connect.guestbook.service.GuestbookService;
 
@Controller
public class GuestbookController {
    @Autowired
    GuestbookService guestbookService;
 
    @GetMapping(path="/list")
    public String list(@RequestParam(name="start", required=false, defaultValue="0") int start,
                       ModelMap model,
                       HttpServletRequest request,
                       HttpServletResponse response) {
 
        String value = null;
        boolean find = false;
        //37~45: 기존의 클라이언트가 들고 온 쿠키
        //쿠키를 검사한 후 내가 원하는 쿠키가 있는지 검사한 후 쿠키의 값이 무엇인지 얻어낸다
        Cookie[] cookies = request.getCookies();
        if(cookies != null) {
            for(Cookie cookie : cookies) {
                if("count".equals(cookie.getName())) {
                    find = true;
                    value = cookie.getValue();
                }
            }
        }
        
      
        if(!find) {
            value = "1";
        }else { // 쿠키를 찾았다면. (쿠키는 문자열이므로 정수로 바꿔주어야 함)
            try {
                int i = Integer.parseInt(value);
                value = Integer.toString(++i);
            }catch(Exception ex) {
                value = "1";
            }
        }
        
   
        // 쿠키 만들기
        Cookie cookie = new Cookie("count", value);
        cookie.setMaxAge(60 * 60 * 24 * 365); // 1년 동안 유지.
        cookie.setPath("/"); // / 경로 이하에 모두 쿠키 적용. 
        response.addCookie(cookie);
        
        
        List<Guestbook> list = guestbookService.getGuestbooks(start);
        
        int count = guestbookService.getCount();
        int pageCount = count / GuestbookService.LIMIT;
        if(count % GuestbookService.LIMIT > 0)
            pageCount++;
        
        List<Integer> pageStartList = new ArrayList<>();
        for(int i = 0; i < pageCount; i++) {
            pageStartList.add(i * GuestbookService.LIMIT);
        }
        
        model.addAttribute("list", list);
        model.addAttribute("count", count);
        model.addAttribute("pageStartList", pageStartList);
        model.addAttribute("cookieCount", value); // jsp에게 전달하기 위해서 쿠키 값을 model에 담아 전송한다.
        
        return "list";
    }
    
    @PostMapping(path="/write")
    public String write(@ModelAttribute Guestbook guestbook,
                        HttpServletRequest request) {
        String clientIp = request.getRemoteAddr();
        System.out.println("clientIp : " + clientIp);
        guestbookService.addGuestbook(guestbook, clientIp);
        return "redirect:list";
    }
}

list.jsp 에서 방명록 전체 수 옆에 방문한 수를 출력하는 el 코드를 추가한다.

• 방명록 전체 수 : ${count }
• 방문한 수 : ${cookieCount }<br><br>

- CookieValue애노테이션 이용

 

 
package kr.or.connect.guestbook.controller;
 
import java.util.ArrayList;
import java.util.List;
 
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
 
import kr.or.connect.guestbook.dto.Guestbook;
import kr.or.connect.guestbook.service.GuestbookService;
 
@Controller
public class GuestbookController {
    @Autowired
    GuestbookService guestbookService;
 
      @GetMapping(path="/list")
    public String list(@RequestParam(name="start", required=false, defaultValue="0") int start,
                       ModelMap model, @CookieValue(value="count", defaultValue="0", required=true) String value,
                       HttpServletResponse response) {
     //request 대신에 @CookieValue를 사용한다
        
        // 쿠키 값을 1증가 시킨다.
        try {
            int i = Integer.parseInt(value);
            value = Integer.toString(++i);
        }catch(Exception ex){
            value = "1";
        }
        
        // 쿠키를 전송한다.
        Cookie cookie = new Cookie("count", value);
        cookie.setMaxAge(60 * 60 * 24 * 365); // 1년 동안 유지.
        cookie.setPath("/"); // / 경로 이하에 모두 쿠키 적용. 
        response.addCookie(cookie);
        
        List<Guestbook> list = guestbookService.getGuestbooks(start);
        
        int count = guestbookService.getCount();
        int pageCount = count / GuestbookService.LIMIT;
        if(count % GuestbookService.LIMIT > 0)
            pageCount++;
        
        List<Integer> pageStartList = new ArrayList<>();
        for(int i = 0; i < pageCount; i++) {
            pageStartList.add(i * GuestbookService.LIMIT);
        }
        
        model.addAttribute("list", list);
        model.addAttribute("count", count);
        model.addAttribute("pageStartList", pageStartList);
        model.addAttribute("cookieCount", value); // 쿠키를 추가한다.
        
        return "list";
    }
    
    @PostMapping(path="/write")
    public String write(@ModelAttribute Guestbook guestbook,
                        HttpServletRequest request) {
        String clientIp = request.getRemoteAddr();
        System.out.println("clientIp : " + clientIp);
        guestbookService.addGuestbook(guestbook, clientIp);
        return "redirect:list";
    }
}