Java的JDBC链接

import java.sql.*;  // 导入数据库操作的包，这种方式是将sql下面的所有的实体类都进行导入

public class JDBCConnect {
    static Connection connection = null;
　　// characterEncoding=utf8 设置编码格式为utf8，serverTimezone=GMT+8设置时区，在mysql 8.0+ 的url需要添加时区，该设置为东八区时间
    static String url ="jdbc:mysql://localhost:3306/studentdb?characterEncoding=utf8&serverTimezone=GMT+8";
    public static Connection getConnection() throws ClassNotFoundException, SQLException {
        Class.forName("com.mysql.jdbc.Driver");　　// 通过反射，获取到mysql的驱动
        return DriverManager.getConnection("url","root","root");　　// 通过驱动管理获取到和数据库的链接
    }

    public static void main(String[] args) throws SQLException, ClassNotFoundException {
//       connection = getConnection();　　
        String url ="jdbc:mysql://localhost:3306/studentdb?characterEncoding=utf8";
        Class.forName("com.mysql.jdbc.Driver");
        connection = DriverManager.getConnection(url,"root","123456");
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery("select * from studentdb");
        while (resultSet.next()){
            resultSet.getInt("ID");
            resultSet.getString("name");
        }
        System.out.println(connection);
    }
}