Hibernate中的CRUD与一对多映射

Question

I have three entities and three tables in database with their relation:

 Class person {

 int id;

 @OneToMany(mappedBy = "person", fetch = FetchType.LAZY)
 List<Comment> comments;

 @OneToMany(mappedBy = "person", fetch = FetchType.LAZY)
 List<CellPhone> cellPhones;

 }

 Class Comment {

 String content;    

 @ManyToOne
 @JoinColumn(name = "id")
 Person person;

 }

 Class CellPhone {

 String mark;    

 @ManyToOne
 @JoinColumn(name = "id")
 Person person;

 }

Does Hibernate support me to do something like that ?

• Insert a new person, it automatically inserts into CellPhone and Comment, not insert by every entity.
• Delete a person with given id, then automatic delete CellPhone and Comment with their relation by id of person ?
• Let's give a person id, it gets person with all Comments and CellPhones ?
• Update something in Comment and CellPhone of a person, and save a person, it will save CellPhone and Comment automatically ?

In general, I just want to set/get CellPhone and Comment for person object, and then call getPerson(person), save(person), or delete(person) ect without get(comment), save(comment) or delete(cellPhone)..

Please help me to clarify it. Thanks.

Answer 1

The answer is yes to all of your questions.

Specifically, for questions 1, 2, and 4 take a look at Hibernate cascading:

1. Hibernate Documentation on cascading
2. Mkyong Article on cascading

For question 3, Hibernate will automatically fetch the other entities once you request them (by calling their get method).

Answer 2

Have you look into CascadeType? Here is a tutorial on this subject. HTH