webix+springmvc session超時跳轉登錄頁面

2016-10-30 13:11:56

引言

最近做項目，發現ajax請求不能在伺服器中直接重定向到登錄頁面。查了些資料發現jquery的ajax請求有人給出了方法。但是webix的ajax請求和jquery的有些區別。這裡模仿jquery的處理方式實現webix的ajax請求session超時跳轉。

具體的做法：

1、查看webix.js源碼發現webix.ajax只有請求前的監聽函數 "onBeforeAjax"， 要做到獲取返回狀態跳轉登錄頁面必須要有個返回的監聽函數，但是源碼沒有。所以我修改了下源碼，加了個返回的監聽函數"onAfterAjax"。

紅色標記部分是我加的代碼，當檢測到ajax完成時，自動執行"onAfterAjax"。（代碼的位置可以搜索webix.js ，條件"onBeforeAjax",然後在對應的位置加入紅色代碼就行

  if (webix.callEvent("onBeforeAjax", [s, t, e, a, o, null, r])) {
            var h = !1;
            if ("GET" !== s) {
                var l = !1;
                for (var c in o)"content-type" == c.toString().toLowerCase() && (l = !0, "application/json" == o[c] && (h = !0));
                l || (o["Content-Type"] = "application/x-www-form-urlencoded")
            }
            if ("object" == typeof e)if (h)e = this.stringify(e); else {
                var u = [];
                for (var d in e) {
                    var f = e[d];
                    (null === f || f === webix.undefined) && (f = ""), "object" == typeof f && (f = this.stringify(f)), u.push(d + "=" + encodeURIComponent(f))
                }
                e = u.join("&")
            }
            e && "GET" === s && (t = t + (-1 != t.indexOf("?") ? "&" : "?") + e,
                e = null), a.open(s, t, !this.H);
            var b = this.Tw;
            b && (a.responseType = b);
            for (var c in o)a.setRequestHeader(c, o[c]);
            var x = this;
            return this.master = this.master || n, a.onreadystatechange = function () {
                if (!a.readyState || 4 == a.readyState) {
                    if (webix.callEvent("onAfterAjax", [a]) === !1) {
                        return false;
                    };
                    if (webix.ajax.count++, i && x && !a.aborted) {
                        if (-1 != webix.ly.find(a))return webix.ly.remove(a);
                        var t, e, s = x.master || x, r = a.status >= 400 || 0 === a.status;
                        "blob" == a.responseType || "arraybuffer" == a.responseType ? (t = "", e = a.response) : (t = a.responseText || "", e = x.J(a)), webix.ajax.$callback(s, i, t, e, a, r)
                    }
                    x && (x.master = null), i = x = n = null
                }
            }, this.qh && (a.timeout = this.qh), this.H ? a.send(e || null) : setTimeout(function () {
                a.aborted || (-1 != webix.ly.find(a) ? webix.ly.remove(a) : a.send(e || null));
            }, 1), this.master && this.master.Ve && this.master.Ve.push(a), this.H ? a : r
        }

2、webix.ajx請求沒有明顯的標誌，jquery.ajax的標識是x-requested-with ，所以我模擬給了個標識requestFlag="webix"(可以自己設置個喜歡的)，用"onBeforeAjax"設置

webix.attachEvent("onBeforeAjax",function(s, t, e, a, o){o["requestFlag"]="webix"})

 3、監聽返回狀態

webix.attachEvent("onAfterAjax",function(xhr){if(xhr.getResponseHeader("sessionstatus")=='timeout'){window.location.href='/webix/login.html'}});

 4、後臺代碼

4.1  攔截器代碼

package com.ljx.filter;

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

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

public class UserInterceptor implements HandlerInterceptor {

    @Override
    public void afterCompletion(HttpServletRequest arg0,
            HttpServletResponse arg1, Object arg2, Exception arg3)
            throws Exception {
    }

    @Override
    public void postHandle(HttpServletRequest arg0,
            HttpServletResponse response, Object arg2, ModelAndView arg3)
            throws Exception {
        response.sendRedirect("/webix/login.html");
    }

    @Override
    public boolean preHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler) throws Exception {
        Object obj = request.getSession().getAttribute("LOGIN");
        if (null == obj) { // 未登錄
            if (request.getHeader("requestFlag") != null
                    && request.getHeader("requestFlag").equalsIgnoreCase(
                            "webix")) { // 如果是ajax請求響應頭會有，requestFlag
                response.setHeader("sessionstatus", "timeout");// 在響應頭設置session狀態
            } else {
                response.sendRedirect(request.getContextPath() + "/login");
            }
            return false;
        }
        return true;
    }

}

 4.2 spring配置文件加入攔截器配置

    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/mvc/*" />
            <bean class="com.ljx.filter.UserInterceptor"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

 4.3 在F12控制台執行下webix.ajax查看效果

webix.ajax().get("/webix/mvc/login.action")