Java基础进阶Map-Properties集合

public class PropertiesTest {
    public static void main(String[] args) {
        //创建Properties集合
        Properties pro = new Properties();
        //向集合中添加元素
        pro.setProperty("url","jdbc:mysql://localhost:3306/newstudy");
        pro.setProperty("driver","com.mysql.jdbc.Driver");
        pro.setProperty("username","root");
        pro.setProperty("password","123");
        //通过key获取Value
        String url = pro.getProperty("url");
        String driver = pro.getProperty("driver");
        String username = pro.getProperty("username", "root");
        String password = pro.getProperty("password");
        System.out.println(url);
        System.out.println(driver);
        System.out.println(username);
        System.out.println(password);
    }
}