关于#jpa#的问题，如何解决？

Customer customer = entityManager.find(Customer.class,1);
    customer.setLastName("xisss");
    System.out.println("sssssssssssssssssssssssss");
    //
    entityManager.clear();
    entityManager.flush();
    Customer customer2 = entityManager.find(Customer.class,1);
    System.out.println(customer);
    System.out.println(customer2);

按理说两个值都是新的才对，但我打印出来 customer是新值，customer2还是老值

我解决了