nokogiri相关
http://nokogiri.org

centos5下面nokogiri爬不到网页：更新libxml2 libxslt。

502重连：

io = StringIO.newloop do  begin    io = open(url)  rescue Exception => e    if e.message == '502 Bad Gateway'      log = "#{Time.now} #{e.message}"      puts log      Rails.logger.info log      sleep(rand()/3+0.05) # 休息一会      next # 重新爬这个页面    end    raise e  end  breakend # io = open(url)doc = Nokogiri::HTML(io)