Hibernate查询打印出来不输数据库格式而是一堆数字，为什么，指定ID查询就正常

Question

public void demo2(){
Session session = HibernateUtils.openSession();
Transaction tx = session.beginTransaction();
Customer customer = session.get(Customer.class, 1l); // 发送SQL语句
System.out.println(customer); // System.out.println(customer.getCust_name()这个正常
tx.commit();
session.close();
}

Hibernate: 
select
    customer0_.cust_id as cust_id1_0_0_,
    customer0_.cust_name as cust_nam2_0_0_,
    customer0_.cust_source as cust_sou3_0_0_,
    customer0_.cust_industry as cust_ind4_0_0_,
    customer0_.cust_level as cust_lev5_0_0_,
    customer0_.cust_phone as cust_pho6_0_0_,
    customer0_.cust_mobile as cust_mob7_0_0_ 
from
    cst_customer customer0_ 
where
    customer0_.cust_id=?

com.itheima.hibernate.day01.Customer@12260d8d