如何使用Ruby Rest-Client处理异常

Question

我最近从Ruby的Net：HTTP类切换到rest-client 1.6.7。

我发现形成请求要容易得多，但与Net：HTTP请求不同，当rest-client获得200以外的任何东西时，请求就会消失。我已经尝试在RestClient.get之后直接放置一个断点，它永远不会被击中 - 所以我做错了。

def get_member_using_card
  resource = "#{@settings_app_uri}api/v1/card/#{self.member_card_num}?token=#{@settings.api_key}"
  response = RestClient.get resource
  if response.code == 200 
    card = JSON.parse(response.body)
    self.customer_id = card['card']['customer_id']
  else
    return 0
  end
end

这导致了这个堆栈跟踪：

RestClient::ResourceNotFound - 404 Resource Not Found:
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient/abstr
act_response.rb:48:in `return!'
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient/reque
st.rb:230:in `process_result'
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient/reque
st.rb:178:in `block in transmit'
        /Users/tim/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/net/http.rb:627:in `start'
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient/reque
st.rb:172:in `transmit'
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient/reque
st.rb:64:in `execute'
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient/reque
st.rb:33:in `execute'
        /Users/tim/.rvm/gems/ruby-1.9.2-p290/gems/rest-client-1.6.7/lib/restclient.rb:68
:in `get'

有人能告诉我如何正确评估响应代码并防止这种异常发生......？

Answer 1

请参阅http://rubydoc.info/gems/rest-client/上的标题例外情况

• 对于200到207之间的结果代码，将返回RestClient :: Response
• 对于结果代码301,302或307，如果请求是get或head，则将遵循重定向
• 对于结果代码303，将遵循重定向并将请求转换为get
• 对于其他情况，将引发保存Response的RestClient :: Exception，将为已知的错误代码抛出特定的异常类

---

RestClient.get 'http://example.com/resource'
➔ RestClient::ResourceNotFound: RestClient::ResourceNotFound`

begin
  RestClient.get 'http://example.com/resource'
rescue => e
  e.response
end
➔ 404 Resource Not Found | text/html 282 bytes

Answer 2

同样在@wich指向的文档中，您可以将一个块传递给RestClient.get，这样它就不会在非200响应代码上引发异常：

# Don't raise exceptions but return the response
RestClient.get('http://example.com/resource'){|response, request, result| response }

请参阅“结果处理”部分：http://www.rubydoc.info/gems/rest-client/1.6.7/frames#Result_handling

Answer 3

rescue RestClient::ExceptionWithResponse => err

Answer 4

可能会发生几个错误，特定的异常类型，如Errno :: EHOSTUNREACH或更通用的ExceptionWithResponse。 Check the readme了解更多信息。