NoMethodError从机械化

Question

运行此代码mecahnize 2.7.3和红宝石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) 

使我这个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 

这是机械化的错误还是我做的有问题？如果是这样如何解决？

编辑：网址显然worng，但即时通讯从一个文件中读取很多网址，其中一些可能是错误的。

EDIT2：可以说我有这样的http://pastie.org/9934756 我需要得到所有的都是正确的URL的头而忽略其他

Answer 1

你写了一个错误的URL文件，试试这个：url = 'http://scouts.org.uk'

Answer 2

您的目标网站正在进行重定向并使用元刷新。更新您的代码，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 

结果：

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

Answer 3

您可以添加此方法来检查有效的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