ruby - 使用splat捕获错误不起作用

Question

我有很多错误需要捕获，因此我将它们全部放入两个数组中并使其成为常量来保存它们，但是，当我运行程序时，我收到了异常:

C:/Users/thomas_j_perkins/bin/ruby/tool/sql_tool/whitewidow/lib/imports/constants_and_requires.rb:62:in `<top (required)>': uninitialized constant RestClient::MaxRedirectsReached (NameError)
        from whitewidow.rb:6:in `require_relative'
        from whitewidow.rb:6:in `<main>'

这是常量的外观:

LOADING_ERRORS = [RestClient::ResourceNotFound, RestClient::InternalServerError, RestClient::RequestTimeout,
                RestClient::Gone, RestClient::SSLCertificateNotVerified, RestClient::Forbidden,
                OpenSSL::SSL::SSLError, Errno::ECONNREFUSED, URI::InvalidURIError, Errno::ECONNRESET,
                Timeout::Error, OpenSSL::SSL::SSLError, Zlib::GzipFile::Error, RestClient::MultipleChoices,
                RestClient::Unauthorized, SocketError, RestClient::BadRequest, RestClient::ServerBrokeConnection,
                RestClient::MaxRedirectsReached]
FATAL_ERRORS = [Mechanize::ResponseCodeError, RestClient::ServiceUnavailable, OpenSSL::SSL::SSLError,
                RestClient::BadGateway]

这是我的使用方式:

begin
  # Do some cool stuff
rescue *FATAL_ERRORS => e
  puts e
end

-

begin
  # Do some more cool stuff
rescue *LOADING_ERRORS => e
  puts e
end

我在收到最高要求的错误的地方做错了吗？万一您需要它，这里是错误指定的整个需求文件:

# Built in libraries
require 'rubygems'
require 'bundler/setup'
require 'mechanize'
require 'nokogiri'
require 'rest-client'
require 'timeout'
require 'uri'
require 'fileutils'
require 'yaml'
require 'date'
require 'optparse'
require 'tempfile'
require 'socket'
require 'net/http'

# Created libraries
require_relative '../../lib/modules/format'
require_relative '../../lib/misc/credits'
require_relative '../../lib/misc/legal'
require_relative '../../lib/misc/spider'
require_relative '../../lib/modules/copy'
require_relative '../../lib/modules/site_info'
require_relative '../../lib/modules/expansion/string_expan'

# Modules that need to be included
include Format
include Credits
include Legal
include Whitewidow
include Copy
include SiteInfo

# Constants used throughout the program
=begin
USER_AGENTS = { # Temporary fix for user agents until I can refactor the YAML file
    1 => 'Mozilla/5.0 (compatible; 008/0.83; http://www.80legs.com/webcrawler.html) Gecko/2008032620',
    2 => 'Mozilla/5.0 (compatible; U; ABrowse 0.6; Syllable) AppleWebKit/420+ (KHTML, like Gecko)',
    3 => 'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.3pre) Gecko/20100403 Lorentz/3.6.3plugin2pre (.NET CLR 4.0.20506)',
    4 => 'Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)',
    5 => 'igdeSpyder (compatible; igde.ru; +http://igde.ru/doc/tech.html)',
    6 => 'larbin_2.6.3 (ltaa_web_crawler@groupes.epfl.ch)',
    7 => 'Mozilla/5.0 (Linux; Android 5.0.2; SAMSUNG SM-T550 Build/LRX22G) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/3.3 Chrome/38.0.2125.102 Safari/537.36',
    8 => 'Dalvik/2.1.0 (Linux; U; Android 6.0.1; Nexus Player Build/MMB29T)',
    9 => 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:15.0) Gecko/20100101 Firefox/15.0.1',
    10 => 'Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)',
}
=end
FORMAT = Format::StringFormat.new
PATH = Dir.pwd
VERSION = Whitewidow.version
SEARCH = File.readlines("#{PATH}/lib/lists/search_query.txt").sample
USER_AGENTS = YAML.load_file("#{PATH}/lib/lists/rand-age.yml")
OPTIONS = {}
USER_AGENT = USER_AGENTS[rand(1..10)]
SKIP = %w(/webcache.googleusercontent.com stackoverflow.com github.com)
LOADING_ERRORS = [RestClient::ResourceNotFound, RestClient::InternalServerError, RestClient::RequestTimeout,
                RestClient::Gone, RestClient::SSLCertificateNotVerified, RestClient::Forbidden,
                OpenSSL::SSL::SSLError, Errno::ECONNREFUSED, URI::InvalidURIError, Errno::ECONNRESET,
                Timeout::Error, OpenSSL::SSL::SSLError, Zlib::GzipFile::Error, RestClient::MultipleChoices,
                RestClient::Unauthorized, SocketError, RestClient::BadRequest, RestClient::ServerBrokeConnection,
                RestClient::MaxRedirectsReached]
FATAL_ERRORS = [Mechanize::ResponseCodeError, RestClient::ServiceUnavailable, OpenSSL::SSL::SSLError,
                RestClient::BadGateway]

Answer 1

我安装了mechanize和rest-clientgem install mechanizegem install rest-client
然后我开了一个IRB session
require mechanizerequire rest-client
然后测试您的FATAL_ERROR数组，并能够引发错误并使用您的代码进行处理。

因此，使用* splat运算符的方式没有问题。

问题出在您的LOADING_ERRORS数组中。

当我尝试对LOADING_ERRORS数组执行相同的操作时，收到的错误消息与您相同。

我克隆了rest-client git存储库，并在lib/restclient/exceptions.rb文件中进行了搜索，似乎没有定义RestClient::MaxRedirectsReached。

如果从数组中删除该异常，则代码将起作用。

在存储库中进行进一步研究之后，有一个history.md文件，它指出:

• Changes to redirection behavior: (#381, #484)
  • Remove RestClient::MaxRedirectsReached in favor of the normal ExceptionWithResponse subclasses. This makes the response accessible on the exception object as .response, making it possible for callers to tell what has actually happened when the redirect limit is reached.
  • When following HTTP redirection, store a list of each previous response on the response object as .history. This makes it possible to access the original response headers and body before the redirection was followed.
  • Follow redirection consistently, regardless of whether the HTTP method was passed as a symbol or string. Under the hood rest-client now normalizes the HTTP request method to a lowercase string.

因此，该异常似乎已从 rest-client库中删除。

您可能要用 RestClient::ExceptionWithResponse替换它