1 LogoutServlet代碼

package www.test.web.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import
 
 javax.servlet.http.HttpSession;

public class LogoutServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        HttpSession session = request.getSession();
        //退出的實質就是從session中將user刪除
        session.removeAttribute("user");
        
        
 
// 將存儲在客戶端的cookie刪除
        Cookie cookie_username = new Cookie("cookie_username", "");
        Cookie cookie_password = new Cookie("cookie_password", "");
        // 設置 cookie 的持久化時間
        cookie_username.setMaxAge(0);
        cookie_password.setMaxAge(0);
        // 設置 cookie 的攜帶路徑
        cookie_username.setPath(request.getContextPath());
        cookie_password.setPath(request.getContextPath());
        
 
// 發送 cookie
        response.addCookie(cookie_username);
        response.addCookie(cookie_password);
        
        //轉發到登錄頁面
        response.sendRedirect(request.getContextPath()+"/login.jsp");
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}

案例33-用戶退出功能