Ajax返回200,却进入了error

$.ajax({
                type: ‘post‘,
                xhrFields: {
                    withCredentials: true
                },
                url: "http://localhost:8060/authentication/form",
                data: {
                    ‘username‘: username,
                    ‘password‘: password,
                    ‘imageCode‘:imageCode
                },
                dataType: "text"
            }).success(function (data) {
                alert("登陆成功");
                /*将返回信息同时存入sessionStorage，cookie*/
                sessionStorage.setItem(‘token‘, JSON.stringify(data));
                document.cookie = "info="+JSON.stringify(data);
                //window.location.href="index.html"
            }).error(function () {
                alert("账号密码不正确");

            });

 response.setCharacterEncoding("UTF-8");
        response.setContentType("application/json;charset=utf-8");
        response.setHeader("Access-Control-Allow-Credentials","true");
        response.setHeader("Access-Control-Allow-Origin", "http://admin.wenfan.com");  //允许跨域请求
        response.setHeader("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
        response.setHeader("Access-Control-Allow-Headers","Authorization");