我们可以使用JDBC查询来执行select语句。

    try(Connection conn = DriverManager.getConnection(JDBC_URL, JDBC_USER, JDBC_PASSWORD)){
        try(Statement stmt = conn.getStatement()){
            try(ResultSet rs = stmt.executeQuery("select * from students where gender=\'M\';")){
                while(rs.next()){
                    long id = rs.getLong(1); //注意：索引从1开始
                    long classId = rs.getLong(2);
                    String name = rs.getString(3);
                    String gender = rs.getString(4);
                }
            }
        } 
    }