编写配置文件

java">username=root
password=123456
url=jdbc:mysql://localhost:3306/myDatabase
driverClassName=com.mysql.cj.jdbc.Driver

编写测试类

java">import java.io.FileInputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Properties;/*** properties配置文件的读取*/
public class FileProperties {public static void main(String[] args) {// 配置类对象Properties properties = new Properties();try (// 创建输入流FileInputStream fis = new FileInputStream(Thread.currentThread().getContextClassLoader().getResource("jdbc.properties").getPath())) {// 加载流文件properties.load(fis);// 获取配置文件的内容/* System.out.println("username: ==>" + properties.getProperty("username"));System.out.println("password: ==>" + properties.getProperty("password"));System.out.println("url: ==>" + properties.getProperty("url"));System.out.println("driverClassName: ==>" + properties.getProperty("driverClassName"));*/Enumeration<?> enumeration = properties.propertyNames();while (enumeration.hasMoreElements()) {String key = (String) enumeration.nextElement();String value = properties.getProperty(key);System.out.println(key + "==>" + value);}} catch (IOException e) {throw new RuntimeException(e);}}
}

结果

使用JDK提供的工具类ResourceBundle（资源绑定类）

java">import java.util.Enumeration;
import java.util.ResourceBundle;public class ResourceBundleTest {public static void main(String[] args) {// 相对路径是类的根目录src,例如：jdbc.properties 的完整路劲=》 src/com/java/study/jdbc.properties/*  使用：不需要.propertiesResourceBundle.getBundle("com.java.study.jdbc");ResourceBundle.getBundle("com/java/study/jdbc");*/// 获取资源绑定器对象，这里我的jdbc.properties 就在src下，所以直接写ResourceBundle bundle = ResourceBundle.getBundle("jdbc");// 通过key获取value/*System.out.println(bundle.getString("username"));System.out.println(bundle.getString("password"));System.out.println(bundle.getString("url"));System.out.println(bundle.getString("driverClassName"));*/Enumeration<String> keys = bundle.getKeys();while (keys.hasMoreElements()) {String key = keys.nextElement();String value = bundle.getString(key);System.out.println(key + "=" + value);}}
}