NoMethodError從機械化

Question

運行此代碼mecahnize 2.7.3和紅寶石2.3.0dev：

require 'mechanize' 
agent = Mechanize.new 

agent.keep_alive = false 
agent.open_timeout = 2 
agent.read_timeout = 2 
agent.ignore_bad_chunking = true 
agent.gzip_enabled = false 

url = 'http:%5C%5Cwww.scouts.org.uk' 

agent.head(url) 

使我這個NoMethodError：

~/.rvm/gems/ruby-head/gems/mechanize-2.7.3/lib/mechanize/http/agent.rb:648:in resolve': undefined  
methodlength' for nil:NilClass (NoMethodError) 

from ~/.rvm/gems/ruby-head/gems/mechanize-2.7.3/lib/mechanize/http/agent.rb:223:in `fetch' 
from ~/.rvm/gems/ruby-head/gems/mechanize-2.7.3/lib/mechanize.rb:459:in `head 

這是機械化的錯誤還是我做的有問題？如果是這樣如何解決？

編輯：網址顯然worng，但即時通訊從一個文件中讀取很多網址，其中一些可能是錯誤的。

EDIT2：可以說我有這樣的http://pastie.org/9934756 我需要得到所有的都是正確的URL的頭而忽略其他

Answer 1

你寫了一個錯誤的URL文件，試試這個：url = 'http://scouts.org.uk'

Answer 2

您的目標網站正在進行重定向並使用元刷新。更新您的代碼，包括那些方法：

require 'mechanize' 

agent = Mechanize.new 
agent.keep_alive = false 
agent.follow_meta_refresh = true 
agent.redirect_ok = true 
agent.open_timeout = 10 
agent.read_timeout = 10 
agent.ignore_bad_chunking = true 
agent.gzip_enabled = false 

url = 'http:%5C%5Cwww.scouts.org.uk' 

begin 
    page_head = agent.head(url) 
rescue Exception => exception 
    puts "Caught exception: #{exception.message}" 
end 

結果：

=> #Caught exception: undefined method `length' for nil:NilClass 

Answer 3

您可以添加此方法來檢查有效的URL或不：

require 'uri' 
def valid?(url) 
    uri = URI.parse(url) 
    if uri.kind_of?(URI::HTTP) == true 
     puts '+' 
    else 
     puts '-' 
    end 
rescue URI::InvalidURIError 
    puts 'false ' 
end 

['http://web.de', 
'http://web.de/', 
'http:%5c%5cweb.de', 
'http:web.de', 
'foo://web.de', 
'http://we b.de', 
'http://|web.de'].each { |i| 
    valid?(i) 
} 

+

+

+

+

false

false