通过 jQuery Ajax 方法访问 Node.js 服务遇到的问题

疑问：请求是成功的，但是跳到 error 中执行，请问各位大侠这是怎么回事啊 直接上代码 Node.js 代码：

http.createServer(function(req, res) {
    var url = parse(req.url),
        pathname = url.pathname;

    console.log('Request URL: http://127.0.0.1:8090' + url.href);
    //解析URL参数到resource对象
    req.resource = restparser.parse(pathname);
    //resource.id 存在，表示是RESTful的请求
    if (req.resource.id) {
        res.writeHead(200, {
            'Content-Type': 'text/plain'
        });
        restrouter.router(req, res, function(stringfyResult) {
            res.end(stringfyResult);
        });
    } else {
        res.writeHead(200, {
            'Content-Type': 'text/plain'
        });
        console.log('Request URL is not in RESTful style!');
        res.end('Request URL is not in RESTful style!');
    }
}).listen(8090, '127.0.0.1');
console.log('Server running at http://127.0.0.1:8090/');

前端请求

$.ajax({
    type: "GET",
    url: "http://127.0.0.1:8090/resources/group",
    contentType: "application/json; charset=utf-8",
    dataType: "jsonp",
    success: function(json) {
        console.log(json);
    },
    error: function(error) {
        console.log(error);
    }
});