JDBC基本连接步骤

public void findStudent() {
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    try {
        //注册 mysql 驱动
        Class.forName("com.mysql.jdbc.Driver");
        //连接数据的基本信息 url ，username，password
        String url = "jdbc:mysql://localhost:3306/springdb";
        String username = "root";
        String password = "123456";
        //创建连接对象
        conn = DriverManager.getConnection(url, username, password);
        //保存查询结果
        List<Student> stuList = new ArrayList<>();
        //创建 Statement, 用来执行 sql 语句
        stmt = conn.createStatement();
        //执行查询，创建记录集，
        rs = stmt.executeQuery("select * from student");
        while (rs.next()) {
            Student stu = new Student();
            stu.setId(rs.getInt("id"));
            stu.setName(rs.getString("name"));
            stu.setAge(rs.getInt("age"));
            //从数据库取出数据转为 Student 对象，封装到 List 集合
            stuList.add(stu);
        }
        
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            //关闭资源
            if (rs != null) ;
            {
                rs.close();
            }
            if (stmt != null) {
                stmt.close();
            }
            if (conn != null) {
                conn.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}