【问题标题】:Scala and HTML parsingScala 和 HTML 解析
【发布时间】:2010-12-14 07:58:28
【问题描述】:

如何将 HTML DOM 文档加载到 Scala 中? XML 单例在尝试加载 xmlns 标记时出错。

import java.net._
import java.io._
import scala.xml._

object NetParse {

   import java.net.{URLConnection, URL}
   import scala.xml._

   def netParse(sUrl: String): Elem = {
       var url = new URL(sUrl)
       var connect = url.openConnection

       XML.load(connect.getInputStream)
   }
}

终于找到了解决办法! - 需要 scala 2.7.7 或更高版本才能工作(2.7.0 有一个致命错误): How-to-use-TagSoup-with-Scala-XML

【问题讨论】:

    标签: html xhtml scala


    【解决方案1】:

    【讨论】:

    【解决方案2】:

    尝试改用scala.xml.parsing.XhtmlParser

    【讨论】:

    • 值得注意的是,该解决方案不适用于“标签汤”——只有格式良好的 XHTML 才能成功解析。因此,与 scala.xml.XML.load* 相比,它基本上只是添加了标准 HTML 实体并显然保留了 CDATA 块。 (就我而言,这就是我所需要的,所以是的!)
    【解决方案3】:

    我刚刚尝试将此答案与 scala 2.8.1 一起使用,并最终使用了以下工作:

    http://www.hars.de/2009/01/html-as-xml-in-scala.html

    我需要的有趣的一点是:

    val parserFactory = new org.ccil.cowan.tagsoup.jaxp.SAXFactoryImpl
    val parser = parserFactory.newSAXParser()
    val source = new org.xml.sax.InputSource("http://www.scala-lang.org")
    val adapter = new scala.xml.parsing.NoBindingFactoryAdapter
    adapter.loadXML(source, parser)
    

    【讨论】:

    • 这也适用于我。但是,我希望能够将原始 HTML 转换为输入源,因此可以在 val source= 行或 adapter.loadXML 部分中。我试过adapter.loadString("<html>..."),但它在格式错误的内容上失败了。有什么想法吗?
    【解决方案4】:

    Scala 刮刀

    我推荐Scala Scraper,它可以让你像这样优雅地解析 HTML:

    // Parse elements from files, URLs or plain strings
    val browser = JsoupBrowser()
    val doc = browser.parseFile("core/src/test/resources/example.html")
    val doc2 = browser.get("http://example.com")
    val doc3 = browser.parseString("<html><h1>parse me</h1></html>")
    
    // Extract the text inside the element with id "header"
    doc >> text("#header")
    
    // Extract the <span> elements inside #menu
    val items = doc >> elementList("#menu span")
    
    // From each item, extract all the text inside their <a> elements
    items.map(_ >> allText("a"))
    

    示例取自 Scala Scraper 的 readme

    【讨论】:

      【解决方案5】:
      /* 
      Copyright (c) 2008 Florian Hars, BIK Aschpurwis+Behrens GmbH, Hamburg 
      Copyright (c) 2002-2008 EPFL, Lausanne, unless otherwise specified. 
      All rights reserved. 
      
      This software was developed by the Programming Methods Laboratory of the 
      Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. 
      
      Permission to use, copy, modify, and distribute this software in source 
      or binary form for any purpose with or without fee is hereby granted, 
      provided that the following conditions are met: 
      
      1. Redistributions of source code must retain the above copyright 
        notice, this list of conditions and the following disclaimer. 
      
      2. Redistributions in binary form must reproduce the above copyright 
        notice, this list of conditions and the following disclaimer in the 
        documentation and/or other materials provided with the distribution. 
      
      3. Neither the name of the EPFL nor the names of its contributors 
        may be used to endorse or promote products derived from this 
        software without specific prior written permission. 
      
      
       THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 
       ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
       IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
       ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 
       FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
       DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
       SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
       CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
       LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
       OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
       SUCH DAMAGE. 
      */ 
      
      package tagsoup 
      
      import org.xml.sax.InputSource 
      import javax.xml.parsers.SAXParser 
      import org.ccil.cowan.tagsoup.jaxp.SAXFactoryImpl 
      import scala.xml.parsing.FactoryAdapter 
      import scala.xml._ 
      
      class TagSoupFactoryAdapter extends FactoryAdapter { 
      
        val parserFactory = new SAXFactoryImpl 
        parserFactory.setNamespaceAware(false) 
      
        val emptyElements = Set("area", "base", "br", "col", "hr", "img", 
                            "input", "link", "meta", "param") 
      
        /** Tests if an XML element contains text. 
         * @return true if element named <code>localName</code> contains text. 
         */ 
        def nodeContainsText(localName: String) = !(emptyElements contains localName) 
      
        /** creates a node. 
        */ 
        def createNode(pre:String, label: String, attrs: MetaData, 
                   scpe: NamespaceBinding, children: List[Node] ): Elem = { 
          Elem( pre, label, attrs, scpe, children:_* ); 
        } 
      
        /** creates a text node 
        */ 
        def createText( text:String ) = 
          Text( text ); 
      
        /** Ignore Processing Instructions 
        */ 
        def createProcInstr(target: String, data: String) = Nil 
      
        /** load XML document 
         * @param source 
         * @return a new XML document object 
         */ 
        override def loadXML(source: InputSource) = { 
          val parser: SAXParser = parserFactory.newSAXParser() 
      
          scopeStack.push(TopScope) 
          parser.parse(source, this) 
          scopeStack.pop 
          rootElem 
        } 
      
      }
      

      How-to-use-TagSoup-with-Scala-XML

      【讨论】:

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