Nokogiri Gem 不会使用 SAX 处理程序解析文件

Question

我有带有标题的xml文件

<?xml version="1.0" encoding="utf-16"?>

它还包含

<transmission xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

当使用 SAX 解析器时，它不会解析。但是当手动去掉编码部分和传输后的属性时；XML解析成功。由于文件很大，我只能使用SAX。有没有其他方法可以在不手动删除编码和传输属性的情况下解析这个xml文件。

示例代码是

      require 'nokogiri'
        include Nokogiri



class P < Nokogiri::XML::SAX::Document

      def initialize
      end

      def start_element(element, attributes = [])
        puts element
      end

      def cdata_block(string)
      end

      def characters(string)
      end

      def end_element(element)
        puts element
      end
 end

    parser = Nokogiri::XML::SAX::Parser.new(P.new())
    parser.parse_file('file_dummy.xml')

Answer 1

尝试实现 SAX 方法套件，看看会得到什么：

require 'nokogiri'

class MyDoc < Nokogiri::XML::SAX::Document
  def cdata_block(str)
    puts "cdata_block: #{str}"
  end

  def characters(str)
    puts "characters: #{str}"
  end

  def comment(str)
    puts "comment: #{str}"
  end

  def end_element(str)
    puts "end_element: #{str}"
  end

  def end_document
    puts "end_document"
  end

  def end_element_namespace(name, prefix = nil, uri = nil)
    puts "end_element_namespace: name: #{name} prefix: #{prefix} uri: #{uri}"
  end

  def error(str)
    puts "error:#{str}"
  end

  def processing_instruction(name, content)
    puts "processing_instruction: name: #{name} content: #{content}"
  end

  def start_document
    puts "start_document"
  end

  def start_element(str, attrs = [])
    puts "start_element: #{str} attrs: #{attrs}"
  end

  def start_element_namespace(name, attrs=[], prefix=nil, uri=nil, ns=[])
    puts "start_element_namespace: name: #{name} attrs: #{attrs} prefix: #{prefix} uri: #{uri} ns: #{ns}"
  end

  def warning(str)
    puts "warning: #{str}"
  end

  def xmldecl(version, encoding, standalone)
    puts "xmldecl: version: #{version} encoding: #{encoding} standalone: #{standalone}"
  end
end

parser = Nokogiri::XML::SAX::Parser.new(MyDoc.new)
parser.parse(File.open(ARGV[0]))

将其保存到脚本并使用以下命令运行它：

ruby path/to/script.rb path/to/file.xml

您应该会看到输出。例如，将以下内容用作简单的 XML 文件：

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications 
      with XML.</description>
   </book>
</catalog>

我得到以下输出：

xmldecl: version: 1.0 encoding:  standalone:
start_document
start_element_namespace: name: catalog attrs: [] prefix:  uri:  ns: []
characters:

start_element_namespace: name: book attrs: [#<struct Nokogiri::XML::SAX::Parser::Attribute localname="id", prefix=nil, uri=nil, value="bk101">] prefix:  uri:  ns: []
characters:

start_element_namespace: name: author attrs: [] prefix:  uri:  ns: []
characters: Gambardella, Matthew
end_element_namespace: name: author prefix:  uri:
characters:

start_element_namespace: name: title attrs: [] prefix:  uri:  ns: []
characters: XML Developer's Guide
end_element_namespace: name: title prefix:  uri:
characters:

start_element_namespace: name: genre attrs: [] prefix:  uri:  ns: []
characters: Computer
end_element_namespace: name: genre prefix:  uri:
characters:

start_element_namespace: name: price attrs: [] prefix:  uri:  ns: []
characters: 44.95
end_element_namespace: name: price prefix:  uri:
characters:

start_element_namespace: name: publish_date attrs: [] prefix:  uri:  ns: []
characters: 2000-10-01
end_element_namespace: name: publish_date prefix:  uri:
characters:

start_element_namespace: name: description attrs: [] prefix:  uri:  ns: []
characters: An in-depth look at creating applications
      with XML.
end_element_namespace: name: description prefix:  uri:
characters:

end_element_namespace: name: book prefix:  uri:
characters:
end_element_namespace: name: catalog prefix:  uri:
end_document

Answer 2

经过多次推荐。我得到了答案。这是@thetinman 的答案。但没有完全吸收。使用 sed 命令将 utf-16 替换为 utf-8 并解析文件。为什么我需要 sed 操作是 nokogiri 导致这个 utf-16 出现问题