Java从XML文件读取JDBC连接

Java从XML文件读取JDBC连接

编写

XML

的方法如下：

<?xml version="1.0" encoding="UTF-8"?><config>    <jdbc>        <url>jdbc:mysql://localhost:3306/javabase</url>        <driver>com.mysql.jdbc.Driver</driver>        <username>java</username>        <password>dhF_r!9Y</password>    </jdbc></config>

假设

config.xml

已调用它并将其放置在类路径的根目录中，下面是一个示例，说明如何在

JAXP

和

Xpath

的帮助下加载它：

InputStream input = Thread.currentThread().getContextClassLoader().getResourceAsStream("config.xml");document document = documentBuilderFactory.newInstance().newdocumentBuilder().parse(new InputSource(input));XPath xpath = XPathFactory.newInstance().newXPath();String url = (String) xpath.compile("//config//jdbc//url").evaluate(document, XPathConstants.STRING);String driver = (String) xpath.compile("//config//jdbc//driver").evaluate(document, XPathConstants.STRING);String username = (String) xpath.compile("//config//jdbc//username").evaluate(document, XPathConstants.STRING);String password = (String) xpath.compile("//config//jdbc//password").evaluate(document, XPathConstants.STRING);// ...

与属性文件相比，它只是非常冗长。这是此类属性文件的示例：

jdbc.url = jdbc：mysql：// localhost：3306 / javabasejdbc.driver = com.mysql.jdbc.Driverjdbc.username = Javajdbc.password = d $ 7hF_r！9Y

假设它

config.properties

已被命名并放置在类路径的根目录中（或它的根路径已添加到类路径中），这是从类路径中加载它的方法：

Properties properties = new Properties();properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("config.properties"));String url = properties.getProperty("jdbc.url");String driver = properties.getProperty("jdbc.driver");String username = properties.getProperty("jdbc.username");String password = properties.getProperty("jdbc.password");// ...