問題描述

我知道這被問了很多次，但我仍然無法讓它工作.我將 xml 字符串轉換為 Document 對象，然后解析它.代碼如下:

I know this was asked many times but I still cannot get it to work. I convert xml string to Document object and then parse it. Here is the code:

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.*;

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try
{
  builder = factory.newDocumentBuilder();  
  Document document = builder.parse( new InputSource( new StringReader( result ) ) );
  Node head = document.getFirstChild();
  if(head != null)
  {                  
    NodeList airportList = head.getChildNodes();      
    for(int i=0; i<airportList.getLength(); i++) {
    Node n = airportList.item(i);                        
    Element airportElem = (Element)n;
  }
}
catch (Exception e) {
  e.printStackTrace();
} 

當我將 Node 對象 n 轉換為 Element 時，我得到一個異常 java.lang.ClassCastException: org.apache.harmony.xml.dom.TextImpl cannot be cast to org.w3c.dom.Element.當我檢查 Node 對象的節點類型時，它顯示 Node.TEXT_NODE.我相信它應該是 Node.ELEMENT_NODE.我對嗎?

When I cast the Node object n to Element I get an exception java.lang.ClassCastException: org.apache.harmony.xml.dom.TextImpl cannot be cast to org.w3c.dom.Element. When I check the node type of the Node object it says Node.TEXT_NODE. I believe it should be Node.ELEMENT_NODE. Am I right?

那么如何將 Node 轉換為 Element，這樣我就可以執行 element.getAttribute("attrName") 之類的操作.

So how do I convert Node to Element, so I can do something like element.getAttribute("attrName").

這是我的 XML:

<?xml version="1.0" encoding="utf-8" ?> 
<ArrayOfCity xmlns:xsd="http://www.w3.org/2001/XMLSchema"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
<City>
  <strName>Abu Dhabi</strName> 
  <strCode>AUH</strCode> 
</City>
<City>
  <strName>Amsterdam</strName> 
  <strCode>AMS</strCode> 
</City>
<City>
  <strName>Antalya</strName> 
  <strCode>AYT</strCode> 
</City>
<City>
  <strName>Bangkok</strName> 
  <strCode>BKK</strCode> 
</City>
</ArrayOfCity>

提前致謝！

推薦答案

當我將 Node 對象 n 轉換為 Element 時，我得到一個異常 java.lang.ClassCastException: org.apache.harmony.xml.dom.TextImpl cannot be cast to org.w3c.dom.Element.當我檢查 Node 對象的節點類型時，它顯示 Node.TEXT_NODE.我相信它應該是 Node.ELEMENT_NODE.我說的對嗎?

When I cast the Node object n to Element I get an exception java.lang.ClassCastException: org.apache.harmony.xml.dom.TextImpl cannot be cast to org.w3c.dom.Element. When I check the node type of the Node object it says Node.TEXT_NODE. I believe it should be Node.ELEMENT_NODE. Am I right?

可能不是，解析器可能是正確的.這意味著您正在解析的某些節點是 文本節點.例如:

Probably not, the parser is probably right. It means that some of the nodes in what you're parsing are text nodes. For example:

<foo>bar</foo>

在上面，我們有一個包含文本節點的 foo 元素.(文本節點包含文本 "bar".)

In the above, we have a foo element containing a text node. (The text node contains the text "bar".)

同樣，考慮:

<foo>
    <bar>baz</bar>
</foo>

如果您的 XML 文檔 literally 與上面類似，則它包含一個根元素 foo 和這些子節點(按順序):

If your XML document literally looks like the above, it contains a root element foo with these child nodes (in order):

• 一個帶有空格的文本節點
• 一個 bar 元素
• 一個包含更多空格的文本節點

請注意，bar 元素不是 foo 的第一個子元素.如果它看起來像這樣:

Note that the bar element is not the first child of foo. If it looked like this:

<foo><bar>baz</bar></foo>

那么 bar 元素將是 foo 的第一個子元素.

then the bar element would be the first child of foo.

這篇關于java xml將節點轉換為元素的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！