package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;


public class DbUtil {
	/**
	 * 取得Connection
	 * @return 
	 */
	public static Connection getConnection(){
		Connection conn=null;
		try {
			JdbcConfig jdbcConfig = XmlConfigReader.getInstance().getJdbcConfig();
			//获取oracle驱动的路径
			Class.forName(jdbcConfig.getDriverName());
			// String url = "jdbc:oracle:thin:@MyDbComputerNameOrIP:1521:ORCL";
			// 数据库连接，oracle代表连接的是oracle数据库；thin:@MyDbComputerNameOrIP代表的是数据库所在的IP地址（可以保留thin:）；
			//1521代表连接数据库的端口号；ORCL代表的是数据库名称
			conn = DriverManager.getConnection(jdbcConfig.getUrl(), jdbcConfig.getUserName(), jdbcConfig.getPassword());
						
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return conn;
		
	}
	
}

<?xml version="1.0" encoding="UTF-8"?>
<config>
	<db-info>
		<driver-name>oracle.jdbc.driver.OracleDriver</driver-name>
		<url>jdbc:oracle:thin:@localhost:1521:oracle</url>
		<user-name>drp1</user-name>
		<password>drp1</password>
	</db-info>
</config>

package util;
/**
 * jdbc配置信息
 * @author liang
 *
 */
public class JdbcConfig {

	

	private String driverName;
	
	private String url;
	
	private String userName;
	
	private String password;
	
	public String getDriverName() {
		return driverName;
	}

	public void setDriverName(String driverName) {
		this.driverName = driverName;
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	public String getUserName() {
		return userName;
	}

	public void setUserName(String userName) {
		this.userName = userName;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	
}

package util;

import java.io.InputStream;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
/**
 * 采用单例解析sys-config.xml文件
 * @author liang
 *
 */
public class XmlConfigReader {

	//单例懒汉式（延迟加载lazy）
	//设置为空，使用在new，不用不new
	private static XmlConfigReader instance = null;
	
	//定义JdbcConfig成员变量，保存jdbc相关配置信息
	private JdbcConfig jdbcConfig = new JdbcConfig();;
	
	private XmlConfigReader(){
		//创建saxReader对象
		SAXReader reader = new SAXReader();
		//通过当前线程的类加载器，获得文件的相对路径，将xml文件读入到输入流
		InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream("sys-config.xml");
		try {
			 // 通过read方法读取xml文件， 转换成Document对象  
			Document doc = reader.read(in);
			
			//获得节点对象，取得jdbc相关的配置信息
			Element driverNameElt = (Element)doc.selectObject("/config/db-info/driver-name");	
			Element urlElt = (Element)doc.selectObject("/config/db-info/url");
			Element userNameElt = (Element)doc.selectObject("/config/db-info/user-name");
			Element passwordElt = (Element)doc.selectObject("/config/db-info/password");
			
			//设置jdbc相关的配置
			jdbcConfig.setDriverName(driverNameElt.getStringValue());
			jdbcConfig.setUrl(urlElt.getStringValue());
			jdbcConfig.setUserName(userNameElt.getStringValue());
			jdbcConfig.setPassword(passwordElt.getStringValue());
		} catch (DocumentException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 加锁，实现多线程的同步机制，防止多线程的访问冲突
	 * @return
	 */
	public static synchronized XmlConfigReader getInstance(){
		if(instance == null){			
			instance = new XmlConfigReader();
		}
		return instance;
	}
	/**
	 * 返回jdbc的相关配置
	 * @return
	 */
	public JdbcConfig getJdbcConfig(){
		return jdbcConfig;
	}
}