var token = localStorage.getItem("token");

$.ajaxSetup({
	dataType: "json",
	cache: false,
    headers: {
        "token": token
    },
    xhrFields: {
	    withCredentials: true
    },
    complete: function(xhr) {
        //token過期，則跳轉到登錄頁面
        if(xhr.responseJSON.code == 401){
            parent.location.href = baseURL + ‘login.html‘;
        }
    }
});

利用ajax全局設置實現攔截器