Dom4j解析带有命名空间的XML文件

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
	<name>长安大学渭水校区</name>
	<Style id="s_ylw-pushpin_hl">
		<IconStyle>
			<scale>1.3</scale>
			<Icon>
				<href>http://maps.google.com/mapfiles/kml/pushpin/grn-pushpin.png</href>
			</Icon>
			<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
		</IconStyle>
		<ListStyle>
		</ListStyle>
	</Style>
	<Style id="s_ylw-pushpin">
		<IconStyle>
			<scale>1.1</scale>
			<Icon>
				<href>http://maps.google.com/mapfiles/kml/pushpin/grn-pushpin.png</href>
			</Icon>
			<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
		</IconStyle>
		<ListStyle>
		</ListStyle>
	</Style>
	<StyleMap id="m_ylw-pushpin">
		<Pair>
			<key>normal</key>
			<styleUrl>#s_ylw-pushpin</styleUrl>
		</Pair>
		<Pair>
			<key>highlight</key>
			<styleUrl>#s_ylw-pushpin_hl</styleUrl>
		</Pair>
	</StyleMap>
	<Placemark>
		<name>长安大学渭水校区</name>
		<LookAt>
			<longitude>108.9032130001538</longitude>
			<latitude>34.36892100035922</latitude>
			<altitude>0</altitude>
			<heading>8.682278169459107e-011</heading>
			<tilt>0</tilt>
			<range>999.7995012938454</range>
			<gx:altitudeMode>relativeToSeaFloor</gx:altitudeMode>
		</LookAt>
		<styleUrl>#m_ylw-pushpin</styleUrl>
		<Point>
			<gx:drawOrder>1</gx:drawOrder>
			<coordinates>108.9032130001538,34.36892100035922,0</coordinates>
		</Point>
	</Placemark>
</Document>
</kml>

public class XMLReader {
	public static void main(String[] args) throws DocumentException {
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("长安大学渭水校区.kml"));
		
		Node name = document.selectSingleNode("//name");
		if (name == null) {
			System.out.println("name节点为null!");
		} else {
			System.out.println(name.getText());
		}
	}
}

public class KMLReader1 {

	public static void main(String[] args) throws DocumentException {
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("长安大学渭水校区.kml"));
		
		//方法一：设置你的xpath的命名空间setNamespaceURIs
		Map<String, String> xmlMap = new HashMap<>();
		xmlMap.put("default", "http://www.opengis.net/kml/2.2");
		XPath xPath = document.createXPath("//default:name");
		xPath.setNamespaceURIs(xmlMap);
		Node name = xPath.selectSingleNode(document);
		System.out.println(name.getText());
		
	}
}

public class KMLReader2 {

	public static void main(String[] args) throws DocumentException {
		//方法二：设置你的DocumentFactory()的命名空间 setXPathNamespaceURIs
		Map<String, String> xmlMap = new HashMap<>();
		xmlMap.put("default", "http://www.opengis.net/kml/2.2");
		xmlMap.put("gx", "http://www.google.com/kml/ext/2.2");
		
		SAXReader reader = new SAXReader();
		reader.getDocumentFactory().setXPathNamespaceURIs(xmlMap);
		Document document = reader.read(new File("长安大学渭水校区.kml"));
		
		Node name = document.selectSingleNode("//default:name");
		System.out.println(name.getText());
		
		Node altitudeMode = document.selectSingleNode("//gx:altitudeMode");
		System.out.println(altitudeMode.getText());
	}
}

public class KMLReader3 {

	public static void main(String[] args) throws DocumentException {
		// 不使用开发环境给你提供的一系列对象，而是用XPath语法中自带的local-name() 和 namespace-uri()
		// 指定你要使用的节点名和命名空间
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("长安大学渭水校区.kml"));

		Node name = document
				.selectSingleNode("//*[local-name()='name' and namespace-uri()='http://www.opengis.net/kml/2.2']");
		System.out.println(name.getText());
	}
}

public class KMLReader4 {

	public static void main(String[] args) throws DocumentException {
		//不使用XPath，直接用element的element方法取一个子元素或elementIterator方法取多个元素
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("长安大学渭水校区.kml"));
		
		Element root = document.getRootElement();
		Element name = root.element("Document").element("name");
		System.out.println(name.getText());
	}
}