由於Encoding :: UndefinedConversionError導致方法失敗：U + 03B1從UTF-8到ISO-8859-1

Question

我正在運行DelayedJob和Mechanize on我的Rails 3.2.13應用程序 - 雖然這兩件事可能不是這個問題的一部分。我的應用程序工作正常，直到一週前。現在，當我運行我的Rails在生產環境中3.2.13應用與我的延遲方法scrape，將會報告：

Jul 03 13:57:19 myapp app/worker 

.1:  (30.7ms) SELECT COUNT(*) AS count_all, priority AS priority FROM "delayed_jobs" WHERE (run_at < '2013-07-03 20:57:19.344207' and failed_at is NULL) GROUP BY priority` 

`Jul 03 13:58:01 myapp app/worker.1: [Worker(host:1d2342a-b234f-4342-bcd7-0afsji3e60dab pid:2)] Person#scrape failed with Encoding::UndefinedConversionError: U+03B1 from UTF-8 to ISO-8859-1 - 0 failed attempts` 

`Jul 03 13:58:01 myapp app/worker.1: 2013-07-03T20:58:01+0000: [Worker(host:1d30481a-cf4f-4344-bad7-0e5e0ae60cab pid:2)] Person#scrape failed with Encoding::UndefinedConversionError: U+03B1 from UTF-8 to ISO-8859-1 - 0 failed attempts` 

`Jul 03 13:58:01 myapp app/worker.1:  (3.1ms) BEGIN 
Jul 03 13:58:01 myapp app/worker.1:  (18.3ms) UPDATE "delayed_jobs" SET "last_error" = 'U+03B1 from UTF-8 to ISO-8859-1 
Jul 03 13:58:01 myapp app/worker.1: /app/vendor/bundle/ruby/1.9.1/gems/mechanize-2.7.1/lib/mechanize/util.rb:57:in `encode'' 
Jul 03 13:58:01 myapp app/worker.1: /app/vendor/bundle/ruby/1.9.1/gems/mechanize-2.7.1/lib/mechanize/util.rb:57:in `encode_to'' 
Jul 03 13:58:01 myapp app/worker.1: /app/vendor/bundle/ruby/1.9.1/gems/mechanize-2.7.1/lib/mechanize/util.rb:43:in `from_native_charset'' 
Jul 03 13:58:01 myapp app/worker.1: /app/vendor/bundle/ruby/1.9.1/gems/mechanize-2.7.1/lib/mechanize/form.rb:243:in `from_native_charset'' 

的U+03B1該代碼對應於字母α（α）。但是，我從來不會在我的代碼中寫入一個alpha，因爲我沒有用它。我認爲這可能與我的Twitter Bootstrap安裝有關，但我只是卸載它，問題並沒有消失。

這是它正在處理的對象。我注意到，在我嘗試過的所有條目中，在mylist屬性之前總是有一個感嘆號。我不知道爲什麼。

19:51:06 web.1 | SQL (0.8ms) INSERT INTO "delayed_jobs" ("attempts", "created_at", "failed_at", "handler", "last_error", "locked_at", "locked_by", "priority", "queue", "run_at", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) [["attempts", 0], ["created_at", Wed, 03 Jul 2013 23:51:06 UTC +00:00], ["failed_at", nil], ["handler", "--- !ruby/object:Delayed::PerformableMethod\nobject: !ruby/ActiveRecord:Doilist\n attributes:\n id: 188\n mylist: ! \"VWQ.U9JF.45.4595.pdf\\r\\nVWQ.U9JF.45.4595.xml\\r\\n \\r\\nVWQ.U9JF.46.1558.pdf\\r\\nVWQ.U9JF.46.1558.xml\\r\\n\n \\r\\nVWQ.U9JF.421234.pdf\\r\\nVWQ.U9JF.461764.xml\\r\\n \\r\\nVWQ.U9JF.434147.pdf\"\n created_at: 2013-07-03 23:51:06.694626000 Z\n updated_at: 2013-07-03 23:51:06.694626000 Z\n myuserid: myemail@email.com\n mypass: mypassword\n mymonth: '7'\n mydate: '1'\n myyear: '1'\nmethod_name: :scrape\nargs: []\n"], ["last_error", nil], ["locked_at", nil], ["locked_by", nil], ["priority", 0], ["queue", nil], ["run_at", Wed, 03 Jul 2013 23:51:06 UTC +00:00], ["updated_at", Wed, 03 Jul 2013 23:51:06 UTC +00:00]]

我很高興應要求發佈任何文件，我猜這是一個複雜的問題。非常感謝您的意見。

Answer 1

我修正了這一點得益於Domon的建議。 Mechanize與之交互的網頁採用ISO-8859-1格式（詳細瞭解如何檢測here），而我的系統試圖以UTF-8格式讀取頁面。爲了解決這個問題，我輸入agent.page.encoding = 'utf-8'到我的scrape方法的腳本中，如Niels Kristian的回答here所示。 （另請參閱denis.peplin的答案，以便進一步說明在哪裏編寫它。）這允許將網頁強制轉換爲我的系統讀取它所需的正確格式（UTF-8）。