方法一使用servlet自帶的HttpSession

註意點： HttpSession應該作為方法的參數

//登入
 public  boolean customerLogin(HttpSession httpSession) {
　　　　httpSession.setAttribute( "customer" , customer);
}

// 退出
public String customerOut(HttpSession httpSession) {
        
        httpSession.removeAttribute( "customer" );
         
 
return "login" ;
    }

方法二：使用spring的@SessionAttributes("logincustomer")

//登入
@Controller
@SessionAttributes("logincustomer")
public class CustomerController {
    public JSONObject customerLogin(@RequestBody JSONObject json, ModelMap model,HttpServletResponse response) {
    model.addAttribute("logincustomer", logincustomer);
    }
}
 

//退出
@RequestMapping(value = "customerout")
    public String customerOut(SessionStatus sessionStatus) {
        sessionStatus.setComplete();// 只對@SessionAttributes("customer")有用，對HttpSession沒用
        // 使用sessionStatus.setComplete();會將所有的session全部清掉，
        return "login";
    }

攔截器(interceptor)

註意：攔截器跟ajax結合用的話使用這條語句response.sendRedirect(request. getContextPath()+"/login.jsp");實現不了調轉，要把結果傳給前端，再在前端上實現跳轉

因此要判斷請求是否是ajax請求

package com.dessert.interceptor;

import java.io.OutputStream;
import java.io.PrintStream;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class CommonInterceptor extends HandlerInterceptorAdapter {
    /*
     * 在攔截器中中有三個方法：
     * preHandler：在進入Handler方法之前執行了，使用於身份認證，身份授權，登陸校驗等，比如身份認證，用戶沒有登陸，攔截不再向下執行，
     * 返回值為false，即可實現攔截；否則，返回true時，攔截不進行執行； postHandler
     * :進入Handler方法之後，返回ModelAndView之前執行，使用場景從ModelAndView參數出發，比如，將公用的模型數據在這裏傳入到視圖，
     * 也可以統一指定顯示的視圖等； afterHandler : 在執行Handler完成後執行此方法，使用於統一的異常處理，統一的日誌處理等；
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
         HttpSession session = request.getSession();
            if (session.getAttribute("logincustomer") != null) {
//                System.out.println(session.getAttribute("costomer"));
                return true;
            }
            // 如果是ajax請求，請求頭會有x-requested-with
            String requestWith = request.getHeader("x-requested-with");
            if (requestWith != null && requestWith.equalsIgnoreCase("XMLHttpRequest")){
                if(session.getAttribute("customer") == null) {
                    return false;
                } else if (session.getAttribute("logincustomer") != null) {
                    return true;
                }
            } else {
                response.sendRedirect(request. getContextPath()+"/login.jsp");
            }
            return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
    }
}

springmvc中對攔截器的配置

<mvc:interceptors>
        <mvc:interceptor>
            <!-- 匹配的是url路徑， 如果不配置或/**,將攔截所有的Controller -->
            <mvc:mapping path="/**" />
            <!-- <mvc:exclude-mapping path="/index.jsp" /> -->
            <mvc:exclude-mapping path="/*login" />
            <mvc:exclude-mapping path="/forgotpwd" />
            <mvc:exclude-mapping path="/customerregister" />
            <mvc:exclude-mapping path="/vaildtel" />
            <mvc:exclude-mapping path="/css/**" />
            <mvc:exclude-mapping path="/js/**" />
            <mvc:exclude-mapping path="/myutil/**" />
            <mvc:exclude-mapping path="/images/**" />
            <!-- <mvc:exclude-mapping path="/*.html" /> -->
            <bean class="com.dessert.interceptor.CommonInterceptor">
            </bean>
        </mvc:interceptor>
        <!-- 當設置多個攔截器時，先按順序調用preHandle方法，然後逆序調用每個攔截器的postHandle和afterCompletion方法 -->
</mvc:interceptors>

Spring+Session+interceptor+ajax(攔截器)的登陸和退出