一、直接使用Driver类

public void testDriver(){
        //1.创建一个Driver 实现类的对象
        Driver driver=new com.mysql.jdbc.Driver();

        //2.准备连接数据库的基本信息：url,user，password
        String url="jdbc:mysql://localhost:3306/test";
        Properties info = new Properties();
        info.put("user", "root");
        info.put("password","1230");

        //3.调用Driver 接口的 connection(url,info)获取数据库连接
        Connection conn=driver.connect(url, info);
        System.out.println(conn);
    }

二、通过文件连接数据库

public Connection getConnection() throws Exception{
        String driverClass = null;
        String jdbcUrl = null;
        String user = null;
        String password = null;

        //读取类路径下的jdbc,properties文件
        InputStream in=
                getClass().getClassLoader().getResourceAsStream("jdbc.properties");
        Properties properties=new Properties();
        properties.load(in);
        driverClass = properties.getProperty("driver");
        jdbcUrl = properties.getProperty("jabcUrl");
        user = properties.getProperty("user");
        password = properties.getProperty("password");

        //通过反射常见 Driver对象
        Driver driver=
                (Driver)Class.forName(driverClass).newInstance();
        Properties info = new Properties();
        info.put("user", user);
        info.put("password", password);

        //通过Driverd 的 connect 方法获取数据库连接
        Connection conn = driver.connect(jdbcUrl, info);

        return conn;
    }

三、通过DriverManager连接数据库

public static void testDriverManager() throws Exception {
        //1，准备连接数据库的4个字符串：驱动全类名、JDBC URL、user、password
        String driverClass = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
        String jdbcUrl = "jdbc:sqlserver://localhost:1433;DatabaseName=Ywpw";
        String user="zyj";
        String password="zyj";

        //2.加载数据库驱动程序（注册驱动）
        Class.forName(driverClass);

        Connection conn=
                DriverManager.getConnection(jdbcUrl, user, password);
        System.out.println(conn);

    }

四、连接各数据库的JDBCUrl

Mysql：jdbc:mysql://localhost:3306/数据库名
SQLServer：jdbc:sqlserver://localhost:1433;DatabaseName=数据库名
Oracle：jdbc:oracle:thin:@localhost:1521:orcl