dom4j中使用xpath解析带命名空间的xml文件,取不到节点的解决办法

panmezihuan0 2011-08-02

使用 DOM4J 的xpath 非常方便,但是,直接使用xpath 取带命名空间的xm文件,会出现取不到节点的问题.具体问题如下

<message id="oNVls-26"
 to="[email protected]"
 from="[email protected]/Smack"
 type="chat">
<subject>zscasvgsadg</subject>
<body>sdvgsdvsaddzsfbnzsdfbvdas</body>
<thread>0pMmg6</thread>
<ext xmlns="infoair:obcs:msg:ext">
<identify>1306663476453admin38</identify>
<sendType>NOR</sendType>
<awokeTime>60</awokeTime>
<x xmlns="infoair:obcs:msg:source" var="130666347645334345"/></ext>
</message>
 

如果想取

identify的值:使用xpathexpression:“/message/ext/identify”将不能取到值

取x的属性值:使用xpathexpression:“/message/ext/identify/x/@var“;也不能取到xvar的属性值

  那么该怎么做了,直接上代码:
public static MessageNode getNode1(String msg)
 throws DocumentException
  {
		SAXReader reader = new SAXReader();
		Document document = reader.read(new StringReader(msg));
		XPath xPath = document.createXPath("/message/a:ext/a:identify");
		Map<String, String> names = new HashMap<String, String>();
		names.put("a", "infoair:obcs:msg:ext");
                MessageNode messageNode = new MessageNode();
		xPath.setNamespaceURIs(names);
		Node node = xPath.selectSingleNode(document);
		messageNode.setIdentify(node.getText());
		xPath = document.createXPath("/message/a:ext/b:x/@var");
		names.put("b", "infoair:obcs:msg:source");
		xPath.setNamespaceURIs(names);
		node = xPath.selectSingleNode(document);
		messageNode.setParentId(node.getText());
		return messageNode;
	}
names.put("a", "infoair:obcs:msg:ext");

   只要 xpath 选择时,加上命名空间就行了

"a"表示前缀,"infoair:obcs:msg:ext"表示命名空间。

具体原因,请见:

  XML 命名空间以及它们如何影响 XPath 和 XSLT (Extreme XML)

相关推荐

hilary0 / 0评论 2020-01-25