使用'ArticleSpider.middlewares.JSPageMiddleware': 
产生问题object has no attribute 'browser'

2017-07-07 05:08:50 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)

2017-07-07 05:08:50 [scrapy.core.scraper] ERROR: Error downloading <GET http://blog.jobbole.com/all-posts/>

Traceback (most recent call last):

  File "C:\Users\sarah\Envs\artical_spider\lib\site-packages\twisted\internet\defer.py", line 1301, in _inlineCallbacks

    result = g.send(result)

  File "C:\Users\sarah\Envs\artical_spider\lib\site-packages\scrapy\core\downloader\middleware.py", line 37, in process_request

    response = yield method(request=request, spider=spider)

  File "C:/Users/sarah/Desktop/LearnPy/s0vkaq/ArticleSpider\ArticleSpider\middlewares.py", line 101, in process_request

    return HtmlResponse(url=spider.browser.current_url, body=spider.browser.page_source, encoding="utf-8", request=request)

AttributeError: 'JobboleSpider' object has no attribute 'browser'

2017-07-07 05:08:50 [scrapy.core.engine] INFO: Closing spider (finished)

前面的DEBUG是这样的（就是可以进入浏览器可以进入这个伯乐在线主页，但后续不能爬取）