dom4j读取xml总结

　　dom4j是一个非常非常优秀的Java XML API，具有性能优异、功能强大和极端易用使用的特点，同时它也是一个开放源代码的软件。

　　操作xml的方式有四种，dom、sax、jdom、dom4j。dom4j性能最好，连Sun的JAXM也在用dom4j.目前许多开源项目中大量采用dom4j，例如Hibernate也用dom4j来读取XML配置文件。

下面是读取xml示例：

xml文件：

<span style="font-family:SimSun;font-size:18px;"><?xml version="1.0" encoding="UTF-8"?>
<config>
	<db-info>
		<driver-name>oracle.jdbc.driver.OracleDriver</driver-name>
		<url>jdbc:oracle:thin:@localhost:1521:orcl</url>
		<user-name>drp</user-name>
		<password>drp</password>
	</db-info>
</config></span>

java读取方法：

<span style="font-family:SimSun;font-size:18px;">public class XmlConfigReader {
<span style="white-space:pre">	</span>//单例
<span style="white-space:pre">	</span>private static XmlConfigReader1 instance = null;
<span style="white-space:pre">	</span>private XmlConfigReader1(){


<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>public static synchronized XmlConfigReader1 getInstance() throws DocumentException {
<span style="white-space:pre">		</span>if (instance == null) {
<span style="white-space:pre">			</span>instance = new XmlConfigReader1();
<span style="white-space:pre">		</span>}
<span style="white-space:pre">		</span>return instance;
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>//读取xml的方法
<span style="white-space:pre">	</span>public String getDriverName() throws DocumentException{
<span style="white-space:pre">		</span>//读取xml
<span style="white-space:pre">		</span>SAXReader reader = new SAXReader();
<span style="white-space:pre">		</span>InputStream in = Thread.currentThread().getContextClassLoader()
<span style="white-space:pre">				</span>.getResourceAsStream("sys-config.xml");
<span style="white-space:pre">		</span>Document document = reader.read(in);
<span style="white-space:pre">		</span>
<span style="white-space:pre">		</span>//读取xml的driver-name节点
<span style="white-space:pre">		</span>Element driverNameElt = (Element) document.selectObject("/config/db-info/driver-name");
<span style="white-space:pre">		</span>return driverNameElt.getStringValue();
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>
}</span>

调用XmlConfigReader的方法，读取xml的节点

<span style="font-family:SimSun;font-size:18px;">	public static void main(String[] args){
		try {
			System.out.println(XmlConfigReader1.getInstance().getDriverName());
		} catch (DocumentException e) {
			e.printStackTrace();
		}
	}</span>

读取结果如下：

和xml一致，成功读取！