如何使用DOM

Question

刪除XML文檔的根節點我想使用DOM API

<hs:PageWrapper> 
    <div id="botton1"/> 
    <div id="botton2"/> 
</hs:PageWrapper> 

所以請從下面的XML文檔的包裝，我只會有這些作爲最終輸出：

<div id="botton1"/> 
<div id="botton2"/> 

我該如何在Java中做到這一點？

Answer 1

你想要做的事不會導致格式良好的XML，因爲在文檔根目錄下會有2個元素。但是，執行你想要的代碼在下面。它獲取包裝器元素的子節點，爲每個節點創建一個新文檔，將節點導入文檔並將文檔寫入String。

public String peel(String xmlString) { 
    StringWriter writer = new StringWriter(); 
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 
    try { 
     DocumentBuilder builder = factory.newDocumentBuilder(); 
     Document document = builder.parse(new InputSource(new StringReader(
       xmlString))); 
     NodeList nodes = document.getDocumentElement().getChildNodes(); 
     for (int i = 0; i < nodes.getLength(); i++) { 
      Node n = nodes.item(i); 
      Document d = builder.newDocument(); 
      Node newNode = d.importNode(n, true); 
      d.insertBefore(newNode, null); 
      writeOutDOM(d, writer); 
     } 
    } catch (ParserConfigurationException e) { 
     e.printStackTrace(); 
    } catch (SAXException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } catch (TransformerFactoryConfigurationError e) { 
     e.printStackTrace(); 
    } catch (TransformerException e) { 
     e.printStackTrace(); 
    } 
    return writer.toString(); 
} 

protected void writeOutDOM(Document doc, Writer writer) 
    throws TransformerFactoryConfigurationError, TransformerException { 
    Result result = new StreamResult(writer); 
    DOMSource domSource = new DOMSource(doc); 
    Transformer transformer = TransformerFactory.newInstance() 
      .newTransformer(); 
    transformer.setOutputProperty("omit-xml-declaration", "yes"); 
    transformer.transform(domSource, result); 
}