dom4j如何读取xml

心已赠人 2022-09-28 01:23 186阅读 0赞

**dom4j如何读取xml**

drp项目中用MyEclipse编码来连接Oracle，首先将ojdbc14.jar拷到对应的目录中，

**DbUtil：与数据库建立相关连接**

/* * 封装数据常用操作 * */ public class DbUtil { public static Connection getConnection(){ Connection conn = null; try{ JdbcConfig jdbcConfig = XmlConfigReader.getInstance().getJdbcConfig(); //初始化驱动程序，打开与数据库连接的通道 Class.forName(jdbcConfig.getDriverName()); conn = DriverManager.getConnection(jdbcConfig.getUrl(),jdbcConfig.getUserName(),jdbcConfig.getPassword()); }catch(ClassNotFoundException e){ e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } public static void main(String[] args){ System.out.println(DbUtil.getConnection()); } }

**sys.config.xml:保存数据库连接字符串**

<?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>drp1</user-name> <password>drp1</password> </db-info> </config>

**XmlConfigReader:读取xml文件中的字符串**

添加对应的jar包 [dom4j-1.6.1.jar][]  和 jaxen-1.1-beta-6.jar

/* * 采用单例模式解析sys.config.xml文件 * */ public class XmlConfigReader { /* * 饿汉式(预先加载) private static XmlConfigReader instance = new XmlConfigReader(); private XmlConfigReader(){ } public static XmlConfigReader getInstance(){ if(instance == null){ instance = new XmlConfigReader(); } return instance; } */ //懒汉式（延迟加载lazy） private static XmlConfigReader instance = null; //保存jdbc相关配置信息 private JdbcConfig jdbcConfig = new JdbcConfig(); private XmlConfigReader(){ SAXReader reader = new SAXReader(); InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream("sys.config.xml"); try{ Document doc = reader.read(in); //取得jdbc相关配置信息 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(); } } //单例模式对外提供的访问入口，synchronized保证线程安全   public static synchronized XmlConfigReader getInstance(){ if(instance == null){ instance = new XmlConfigReader(); } return instance; } /* * 返回jdbc相关配置 * */ public JdbcConfig getJdbcConfig(){ return jdbcConfig; } public static void main(String[] args) { JdbcConfig jdbcConfig = XmlConfigReader.getInstance().getJdbcConfig(); System.out.println(jdbcConfig);//要求写jdbcConfig的toString()方法，否则报错 }

右键-->Run as-->Java Application，

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结果如下 ，表示连接成功：

com.orcl.drp.util.JdbcConfig\{driverName:oracle.jdbc.driver.OracleDriver,url:jdbc:oracle:thin:@localhost:1521:orcl,userName:drp1\}

**总结：**

运行时，这段报了个路径错误，看了好几遍，竟然没看出来xml文件名“.”写成了"-"，还好心态好，不然直接晕倒。哈哈。。

**感谢您的阅读！**

[dom4j-1.6.1.jar]: http://download.csdn.net/detail/u010928364/9068341
[Center]: /images/20220708/03043110abb5487aa8f5442598e200c0.png