dom4j是一个java 的XML API，用来读写XML文件。

使用dom4j解析XML文件，首先需要在官网下载dom4j-1.6.1.zip。

URL：http://sourceforge.net/projects/dom4j/files/latest/download?source=files。

创建的Java 工程目录结构：

我们以解析数据库连接和配置文件c3p0.xml为例。

c3p0.xml

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config><init><name>Oracle</name><driver>oracle.jdbc.driver.OracleDriver</driver><url>jdbc:oracle:thin:@192.168.1.29:1521:orcl</url><user>orcl</user><password>orcl</password><initPoolSize>5</initPoolSize><minPoolSize>2</minPoolSize><maxPoolSize>20</maxPoolSize><maxStatements>20</maxStatements><maxIdleTime>60</maxIdleTime><acquireIncrement>5</acquireIncrement><checkoutTimeout>3000</checkoutTimeout></init>
</c3p0-config>

C3p0.java

package com.xml.parse.file;public class C3p0 {private String name;private String driver;private String url;private String user;private String password;private String initPoolSize;private String minPoolSize;private String maxPoolSize;private String maxStatements;private String maxIdleTime;private String acquireIncrement;private String checkoutTimeout;public C3p0() {}public C3p0(String name, String driver, String url, String user,String password, String initPoolSize, String minPoolSize,String maxPoolSize, String maxStatements, String maxIdleTime,String acquireIncrement, String checkoutTimeout) {this.name = name;this.driver = driver;this.url = url;this.user = user;this.password = password;this.initPoolSize = initPoolSize;this.minPoolSize = minPoolSize;this.maxPoolSize = maxPoolSize;this.maxStatements = maxStatements;this.maxIdleTime = maxIdleTime;this.acquireIncrement = acquireIncrement;this.checkoutTimeout = checkoutTimeout;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDriver() {return driver;}public void setDriver(String driver) {this.driver = driver;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}public String getUser() {return user;}public void setUser(String user) {this.user = user;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getInitPoolSize() {return initPoolSize;}public void setInitPoolSize(String initPoolSize) {this.initPoolSize = initPoolSize;}public String getMinPoolSize() {return minPoolSize;}public void setMinPoolSize(String minPoolSize) {this.minPoolSize = minPoolSize;}public String getMaxPoolSize() {return maxPoolSize;}public void setMaxPoolSize(String maxPoolSize) {this.maxPoolSize = maxPoolSize;}public String getMaxStatements() {return maxStatements;}public void setMaxStatements(String maxStatements) {this.maxStatements = maxStatements;}public String getMaxIdleTime() {return maxIdleTime;}public void setMaxIdleTime(String maxIdleTime) {this.maxIdleTime = maxIdleTime;}public String getAcquireIncrement() {return acquireIncrement;}public void setAcquireIncrement(String acquireIncrement) {this.acquireIncrement = acquireIncrement;}public String getCheckoutTimeout() {return checkoutTimeout;}public void setCheckoutTimeout(String checkoutTimeout) {this.checkoutTimeout = checkoutTimeout;}}

ParseXML.java：

package com.xml.parse.file;import java.io.InputStream;import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;public class ParseXML {private static ParseXML instance = null;private C3p0 c3p0 = new C3p0();public ParseXML(){SAXReader  reader = new SAXReader();InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream("config/c3p0.xml");try {Document document = reader.read(in);Element root = document.getRootElement();Element e = root.element("init");Element name = (Element)e.element("name");Element driver = (Element)e.element("driver");Element url = (Element)e.element("url");Element user = (Element)e.element("user");Element password = (Element)e.element("password");Element initPoolSize = (Element)e.element("initPoolSize");Element minPoolSize = (Element)e.element("minPoolSize");Element maxPoolSize = (Element)e.element("maxPoolSize");Element maxStatements = (Element)e.element("maxStatements");Element maxIdleTime = (Element)e.element("maxIdleTime");Element acquireIncrement = (Element)e.element("acquireIncrement");Element checkoutTimeout = (Element)e.element("checkoutTimeout");c3p0.setName(name.getStringValue());c3p0.setDriver(driver.getStringValue());c3p0.setUrl(url.getStringValue());c3p0.setUser(user.getStringValue());c3p0.setPassword(password.getStringValue());c3p0.setInitPoolSize(initPoolSize.getStringValue());c3p0.setMinPoolSize(minPoolSize.getStringValue());c3p0.setMaxPoolSize(maxPoolSize.getStringValue());c3p0.setMaxStatements(maxStatements.getStringValue());c3p0.setMaxIdleTime(maxIdleTime.getStringValue());c3p0.setAcquireIncrement(acquireIncrement.getStringValue());c3p0.setCheckoutTimeout(checkoutTimeout.getStringValue());} catch (DocumentException e) {e.printStackTrace();}}public static synchronized ParseXML getInstance() {if(instance == null){instance = new ParseXML();}return instance;}public C3p0 getC3p0() {return c3p0;}}

XMLTest.java:

package com.xml.parse.file;public class XMLTest {public static void main(String args[]){ParseXML xml = ParseXML.getInstance();System.out.println("---name---");System.out.println(xml.getC3p0().getName());System.out.println("---driver---");System.out.println(xml.getC3p0().getDriver());System.out.println("---url---");System.out.println(xml.getC3p0().getUrl());System.out.println("---user---");System.out.println(xml.getC3p0().getUser());System.out.println("---password---");System.out.println(xml.getC3p0().getPassword());System.out.println("---initPoolSize---");System.out.println(xml.getC3p0().getInitPoolSize());System.out.println("---minPoolSize---");System.out.println(xml.getC3p0().getMinPoolSize());System.out.println("---maxPoolSize---");System.out.println(xml.getC3p0().getMaxPoolSize());System.out.println("---maxStatements---");System.out.println(xml.getC3p0().getMaxStatements());System.out.println("---maxIdleTime---");System.out.println(xml.getC3p0().getMaxIdleTime());System.out.println("---acquireIncrement---");System.out.println(xml.getC3p0().getAcquireIncrement());System.out.println("---checkoutTimeout---");System.out.println(xml.getC3p0().getCheckoutTimeout());}
}

运行XMLTest.java中的main方法。结果如下：

好，到此使用dom4j解析XML文件完毕，请大家指正！