尝试从 Word 文档中获取内容时出现“Ole::Storage::FormatError：OLE2 签名无效”

Question

我正在使用 Rails 5。我想从 Word 文档 (.doc) 中获取文本，所以我正在使用此代码

  text = nil
  MSWordDoc::Extractor.load(file_location) do |ctl00_MainContent_List1_grdData|
    text = contents.whole_contents
  end

但我收到以下错误。我的 Gemfile 中有这颗宝石

gem 'msworddoc-extractor'

我还需要做什么才能从 Word 文档中获取内容？如果我可以对.docx 文件应用与.doc 文件相同的代码，那就太好了。

/Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/support.rb:201: warning: constant ::Fixnum is deprecated
Ole::Storage::FormatError: OLE2 signature is invalid
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:378:in `validate!'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:370:in `initialize'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:112:in `new'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:112:in `load'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:79:in `initialize'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:85:in `new'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/ruby-ole-1.2.12/lib/ole/storage/base.rb:85:in `open'
    from /Users/davea/.rvm/gems/ruby-2.4.0/gems/msworddoc-extractor-0.2.0/lib/msworddoc/extractor.rb:11:in `load'
    from /Users/davea/Documents/workspace/myproject/app/services/msword_processor_service.rb:12:in `pre_process_data'
    from /Users/davea/Documents/workspace/myproject/app/services/abstract_import_service.rb:88:in `process_race_data'
    from (irb):2
    from /Users/davea/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.1/lib/rails/commands/console.rb:65:in `start'
    from /Users/davea/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.1/lib/rails/commands/console_helper.rb:9:in `start'
    from /Users/davea/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:78:in `console'
    from /Users/davea/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
    from /Users/davea/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.1/lib/rails/commands.rb:18:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

Answer 1

您正在使用的 gem 具有 gem ruby-ole 作为依赖项。可以看in the code:

ole = Ole::Storage.open(file)

当您导入 Word 文档时，它实际上是由 ruby-ole gem 打开的。如果 gem 无法验证文件的格式是否正确，它将 raise an exception：

raise FormatError, "OLE2 signature is invalid" unless magic == MAGIC

MAGIC 指的是.doc 文件的标头，应该看起来像like this：

# i have seen it pointed out that the first 4 bytes of hex,
# 0xd0cf11e0, is supposed to spell out docfile. hmmm :)
MAGIC = "\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1"  # expected value of Header#magic

这是指CFBF header format 用于 Word 文档：

BYTE _abSig[8];             // [00H,08] {0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1,
                            // 0x1a, 0xe1} for current version

您的 .doc 文件不是有效的 Word 文档，或者它是由 ruby-ole gem 不支持的较新版本的 Word 创建的。

我建议使用多个不同的 Word 文档重试该操作以找到兼容的类型，然后以该格式重新保存原始文档以重试。