scrapy如何使同一个session发送不同的请求

Question

本人在写爬虫时，需要先发送一个提交表单的请求，然后获得这个表单返回的jessionid的这一个cookie， 在通过这个cookie发送请求来获得数据。但是这个cookie的有效期是在一个session内，如何将这两个请求保持在同一个session里，求大神解释。
代码如下：` def start_requests(self):

    form_data = {
        'sourceid': 'sdal',
        'apptype': '',
        'appcode': '',
        'developer': '',
        'channel': '',
        'usertype': '',
        'userid': '',
        'actionCode': '20',
        'achange': '',
        'airname': '山航',
        'airways': 'SC',
        'discount': '',
        'fare': '',
        'fnumber': '',
        'ftime': '',
        'orderIndex': '',
        'planetype': '',
        'ttime': '',
        'vendorid': '',
        'seatClass': '',
        'afromN': '济南',
        'atoN': '厦门',
        'afrom': 'TNA',
        'ato': 'XMN',
        'fdate_submit': '20170714',
        'tdate_submit': '',
    }
    s = urllib.urlencode(form_data)
    print s
    yield scrapy.Request('http://m.shandongair.com/mainSrv', body=s, headers=self.headers,
                         method='POST', meta=self.meta, callback=self.parse)

def parse(self, response):
    cookie = response.headers.getlist('Set-Cookie')
    print 'Cookie', cookie
    url = 'http://m.shandongair.com/jsp/flight/flightresult.jsp'
    jess_cookie = self.parse_cookies(cookie[0])
    print jess_cookie
    return scrapy.Request(url, headers=self.headers, dont_filter=True,
                          meta={'cookiejar': response.meta['cookiejar']},
                          method='GET', meta=self.meta, callback=self.parse_res)`
                          
 返回的异常如下：

2017-07-14 10:26:27 [scrapy.downloadermiddlewares.cookies] DEBUG: Received cookies from: <200 http://m.shandongair.com/mainSrv>
Set-Cookie: JSESSIONID=0FFD13B49DAB8E6BD267873193A326B7; Path=/

2017-07-14 10:26:27 [scrapy.core.engine] DEBUG: Crawled (200) <POST http://m.shandongair.com/mainSrv> (referer: None)
Cookie ['JSESSIONID=0FFD13B49DAB8E6BD267873193A326B7; Path=/']
{'JSESSIONID': '0FFD13B49DAB8E6BD267873193A326B7'}
2017-07-14 10:26:27 [scrapy.downloadermiddlewares.cookies] DEBUG: Sending cookies to: <GET http://m.shandongair.com/jsp/flight/flightresult.jsp>
Cookie: JSESSIONID=0FFD13B49DAB8E6BD267873193A326B7

2017-07-14 10:26:35 [scrapy.downloadermiddlewares.cookies] DEBUG: Received cookies from: <500 http://m.shandongair.com/jsp/flight/flightresult.jsp>
Set-Cookie: JSESSIONID=A685C5C215EA85A2A665365C5A063175; Path=/

2017-07-14 10:26:35 [scrapy.downloadermiddlewares.retry] DEBUG: Retrying <GET http://m.shandongair.com/jsp/flight/flightresult.jsp> (failed 1 times): 500 Internal Server Error
2017-07-14 10:26:35 [scrapy.downloadermiddlewares.cookies] DEBUG: Sending cookies to: <GET http://m.shandongair.com/jsp/flight/flightresult.jsp>
Cookie: JSESSIONID=A685C5C215EA85A2A665365C5A063175

2017-07-14 10:26:42 [scrapy.downloadermiddlewares.retry] DEBUG: Retrying <GET http://m.shandongair.com/jsp/flight/flightresult.jsp> (failed 2 times): 500 Internal Server Error
2017-07-14 10:26:42 [scrapy.downloadermiddlewares.cookies] DEBUG: Sending cookies to: <GET http://m.shandongair.com/jsp/flight/flightresult.jsp>
Cookie: JSESSIONID=A685C5C215EA85A2A665365C5A063175

2017-07-14 10:26:48 [scrapy.downloadermiddlewares.retry] DEBUG: Gave up retrying <GET http://m.shandongair.com/jsp/flight/flightresult.jsp> (failed 3 times): 500 Internal Server Error
2017-07-14 10:26:48 [scrapy.core.engine] DEBUG: Crawled (500) <GET http://m.shandongair.com/jsp/flight/flightresult.jsp> (referer: http://m.shandongair.com/mainSrv) ['partial']
2017-07-14 10:26:48 [scrapy.spidermiddlewares.httperror] INFO: Ignoring response <500 http://m.shandongair.com/jsp/flight/flightresult.jsp>: HTTP status code is not handled or not allowed
2017-07-14 10:26:48 [scrapy.core.engine] INFO: Closing spider (finished)
2017-07-14 10:26:48 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
``

Answer 1

用cookiejar
cookiejar文档