捕获Mechanize 404 => Net :: HTTPNotFound

Question

我写了一个简单的函数来处理url的获取:

def tender_page_get url, agent
  sleep(rand(6)+2)
  begin
    return agent.get(url).parser
  rescue Errno::ETIMEDOUT, Timeout::Error, Net::HTTPNotFound
    EYE.debug "--winter sleep #{url}"
    puts "-x-#{url}"
    sleep(300)
    tender_page_get url, agent
  rescue => e
    puts "-x-#{url}"
    EYE.debug "--unknown exception"
    EYE.debug "#{url} #{e.inspect}"
  end
end

问题是,即使我Net::HTTPNotFound在第一个救援区中捕获,我仍然在我的日志记录中看到:

--unknown exception
{url} 404 => Net::HTTPNotFound

这意味着第二个救援区抓住了这个例外.可能是什么原因？

Answer 1

Mechanize为404而不是Net :: HTTPNotFound引发Mechanize :: ResponseCodeError.Mechanize :: ResponseCodeError上的to_s如下所示:

def to_s
  "#{response_code} => #{Net::HTTPResponse::CODE_TO_OBJ[response_code]}"
end

这将返回'404 => Net :: HTTPNotFound',这使得它看起来像是引发的异常.