JAVA JDBC 连接数据库

方式一

Driver driver = new com.mysql.jdbc.Driver();
String url = "jdbc:mysql://localhost:3306/test";
Properties info = new Properties();
info.setProperty("user","root");
info.setProperty("password","1234");
Connection connection = driver.connect(url,info);
System.out.println(connection);

 方式二 使用反射

Class cl = Class.forName("com.mysql.jdbc.Driver");

Driver driver = (Driver) cl.newInstance();
String url = "jdbc:mysql://localhost:3306/test";
Properties info = new Properties();
info.setProperty("user","root");
info.setProperty("password","1234");
Connection connection = driver.connect(url,info);
System.out.println(connection);

 方式三 使用Drivermanager

//利用反射
        Class cl = Class.forName("com.mysql.jdbc.Driver");

        Driver driver = (Driver) cl.newInstance();
        String url = "jdbc:mysql://localhost:3306/test";
        String user = "root";
        String password="1234";
        DriverManager.registerDriver(driver);
        Connection connection = DriverManager.getConnection(url,user,password);
        System.out.println(connection);

 方式4 可以省略显示的驱动加载

String url = "jdbc:mysql://localhost:3306/test";
        String user = "root";
        String password="1234";
        //利用反射
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(url,user,password);
        System.out.println(connection);

方式5 通过配置文件加载配置信息

InputStream is = connectTest.class.getClassLoader().getResourceAsStream("jdbcInfo.properties");
        Properties pro = new Properties();
        pro.load(is);

        String user = pro.getProperty("user");
        String password = pro.getProperty("password");
        String url = pro.getProperty("url");
        String driverClass = pro.getProperty("driverClass");
        //利用反射
        Class.forName(driverClass);
        Connection connection = DriverManager.getConnection(url,user,password);
        System.out.println(connection);