Cascade – JPA & Hibernate annotation common mistake

Often times, developers are mix used the JPA and Hibernate annotation together, it will caused a very common mistake – JPA cascade type annotation is not working in Hibernate?

During the code review section, i find out many Java developers are not aware of this mistake and causing the program failed to execute the cascade operation to the related entities. I will take this one-to-many hibernate example for the demonstration.

Mistake

In the one-to-many example, many developers declared the JPA cascade options as following :

...
@Entity
@Table(name = "stock", catalog = "mkyong", uniqueConstraints = {
		@UniqueConstraint(columnNames = "STOCK_NAME"),
		@UniqueConstraint(columnNames = "STOCK_CODE") })
public class Stock implements java.io.Serializable {
    ...
    private Set<StockDailyRecord> stockDailyRecords = 
                                              new HashSet<StockDailyRecord>(0);
 
    @OneToMany(fetch = FetchType.LAZY, 
       cascade = {CascadeType.PERSIST,CascadeType.MERGE }, 
       mappedBy = "stock")
    public Set<StockDailyRecord> getStockDailyRecords() {
	return this.stockDailyRecords;
    }
 
    public void setStockDailyRecords(Set<StockDailyRecord> stockDailyRecords) {
	this.stockDailyRecords = stockDailyRecords;
    }
    ...

Save it with Hibernate session.

        stockDailyRecords.setStock(stock);        
        stock.getStockDailyRecords().add(stockDailyRecords);
 
        session.save(stock);
        session.getTransaction().commit();

What the code trying to do is when you save a “stock”, it will save the associated stockDailyRecords as well. Everything look fine, but THIS IS NOT WORKING, the cascade options will not execute and save the stockDailyRecords. Can you spot the mistake?

Explanation

Look in the code, @OneToMany is from JPA , it expected a JPA cascade – javax.persistence.CascadeType. However when you save it with Hibernate session, org.hibernate.engine.Cascade will do the following checking …

	if ( style.doCascade( action ) ) {
		cascadeProperty(
	          persister.getPropertyValue( parent, i, entityMode ),
		  types[i],
    	          style,
	          anything,
	          false
		);
	}

The Hibernate save process will causing a ACTION_SAVE_UPDATE action, but the JPA will pass a ACTION_PERSIST and ACTION_MERGE, it will not match and causing the cascade failed to execute.

@see source code

  • org.hibernate.engine.Cascade
  • org.hibernate.engine.CascadeStyle
  • org.hibernate.engine.CascadingAction

Solution

Delete the JPA cascade – javax.persistence.CascadeType, replace it with Hibernate cascade – org.hibernate.annotations.Cascade, with CascadeType.SAVE_UPDATE.

...
@Entity
@Table(name = "stock", catalog = "mkyong", uniqueConstraints = {
		@UniqueConstraint(columnNames = "STOCK_NAME"),
		@UniqueConstraint(columnNames = "STOCK_CODE") })
public class Stock implements java.io.Serializable {
    ...
    private Set<StockDailyRecord> stockDailyRecords = 
                                              new HashSet<StockDailyRecord>(0);
 
    @OneToMany(fetch = FetchType.LAZY, mappedBy = "stock")
    @Cascade({CascadeType.SAVE_UPDATE})
    public Set<StockDailyRecord> getStockDailyRecords() {
	return this.stockDailyRecords;
    }
 
    public void setStockDailyRecords(Set<StockDailyRecord> stockDailyRecords) {
	this.stockDailyRecords = stockDailyRecords;
    }
    ...

Now, it work as what you expected.

Conclusion

It look like an incompatible issue between JPA and Hibernate cascade annotation, if Hibernate is a JPA implementation, what may causing the misunderstand in between?

Tags :

About the Author

mkyong
Founder of Mkyong.com and HostingCompass.com, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.

Comments

  • Pingback: Hibernate and JPA Annotations | On Java Development()

  • http://[email protected] Anup Mehta

    This article is extremely confusing .
    I saw one of your example where you used JPA cascade option
    http://www.mkyong.com/hibernate/hibernate-one-to-one-relationship-example-annotation/
    (refer stock.java )
    And than later you used hibernate’s sesssion.save(stock)
    On net too I have observed that people use CascadeType.All and use session.save(object) and the code works fine .
    Does this mean that save() method exists in both Hibernate and JPA ? Please clear my doubt.

  • vijay

    Hi All,

    I am new to hibernate , fist Thanks for this post.
    I am doing the debug this code and i have requirement i would like to introduce the
    delete functionality with annotation i.e once we delete the parent its need to be delete child records ie i need to introduce the ondelete cascade feature.

    Could you please help how to introduce this feature.

    Thanks
    Vijay

  • http://www.jeeaps.pl Dawid Furman

    Yeah! Thank you very much for your great article!! Now all is clear!
    best regard from Poland

  • dan carter

    Hi,

    As this article is quite highly ranked in google still, it’s worth pointing out that hibernate does now support JPA cascade. No need to use the hibernate specific annotation.

    import javax.persistence.CascadeType;
    import javax.persistence.FetchType;
    import javax.persistence.OneToOne;

    @OneToOne(mappedBy = “device”, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private LoginService loginService;

    Using 4.2.3-Final here

    • dan carter

      Actually, i should point out i am using JPA API here to save (well actually using spring-data which in turn uses jpa entity-manager)

      And actually re-reading this article i see i have misunderstood it. Ii thought you were talking about how to use hibernate with JPA, but in fact you are explaining how to use the hibernate native API with no JPA at all.

  • Muhammad Bilal

    I have been working on this issue for a long time .. didnt got this clicked in ma mind. your blog help Alot. Thanks

  • Laxmikanth

    Even I was struggling why Hibernate is not saving child objects. Your blog helped me dude..
    Thanks alot..!!

  • Abhay

    Any recommended book for JPA & JPQL.
    thanks in advance…

  • srinu

    its good..

  • Shivang Gupta

    Thanks a lot!! I was facing this exact issue. Saved me some time in identifying the problem, and a lot of time in finding the solution. This post, as well as others (especially those on Spring) have been a big help. Keep blogging and enlightening us… :)

  • nelson

    It would be greate if there was a searchBox in the site.

  • Pingback: Hibernate or JPA annotations to use | BlogoSfera()

  • http://ayata.com Arup

    helps a lot.

  • dli7mar

    Hi mkyong,

    In a JPA/Hibernate project, can I define a generic method in dao class like this:

    public void save(T entity) {
    em.persist(entity);
    }

    and then call this method in managed beans, pass in different entities?
    I would like to avoid having multiple save methods in dao, one for each entity class.

    Many Thanks.

  • Sina

    I have a ManyToMany relation (Role – Activity – RoleActivity).
    In Role Entity I have added @Cascade({CascadeType.DELETE_ORPHAN })
    But while deleting a role I have this error:
    java.sql.SQLIntegrityConstraintViolationException: ORA-02292: integrity constraint (USR_SPS.FG_RL_ID) violated – child record found
    It seems hibernate annotation doesnt work fine

  • Pingback: Hibernate – Cascade example (save, update, delete and delete-orphan)()

  • Alex

    I am using JPA2 and hibernate 3.6. Until now I was able to implement everything I wanted using only JPA-annotations.
    I exclusively use JPA-Annotations and EntityManager. And there’s absolutely nothing wrong (except for and probably atomikos related issue, which is likely to be a configuration fault).

    I think the main mistake is mixing up hibernate and JPA. At design time you should make a decision which one you are going to use and then you have to stick to it. If you don’t you’re using bad design.

    In my opinion it would be less confusion for beginners, if you point this out. This topic suggests Hibernate has a generel problem with CascadeType or maybe other JPA-annotations.

  • Pingback: Confusion between JPA and Hibernate cascading - Question Lounge()

  • http://marybelarcher.blogspot.com/ marcher

    I cannot thank you enough! You saved me from spending many more hours digging around and “experimenting” to solve foreign key constraint issues. :’) I have a comment though: for the Hibernate CascadeType to “kick in” I still needed to specify the JPA one in my entity. Per Hibernate’s documentation on cascading ( http://docs.jboss.org/hibernate/stable/annotations/reference/en/html/entity.html#entity-hibspec-cascade ) this is recommended, but in my case it seems to be actually required :|

    Anyway, thanks a lot, again :)

    • http://www.mkyong.com mkyong

      You’re welcome, thanks for sharing your experience as well. :)

      • vijay

        Hi Yong,

        I am new to hibernate , fist Thanks for this post.
        I am doing the debug this code and i have requirement i would like to introduce the
        delete functionality with annotation ie once we delete the parent its need to be delete child records ie i need to introduce the ondelete cascade feature.
        Could you please help how to introduce this feature.

      • vijay

        Hi Yong,

        I am new to hibernate , fist Thanks for this post.
        I am doing the debug this code and i have requirement i would like to introduce the
        delete functionality with annotation i.e once we delete the parent its need to be delete child records ie i need to introduce the ondelete cascade feature.

        Could you please help how to introduce this feature.

    • Dhiraj

      Thanks for this post. I had to debug all the way down to figure this insconsistency.

    • [email protected]

      You both are godsends. Adding the “optional” JPA annotation from the docs fixed my cascade. I wasted time “experimenting” with the foreign keys and annotations for my objects and tables.

  • Neal

    Yep ran into this issue headfirst…and helped me solve. Thanks a bunch.
    But now my code is tied to Hibernate – which goes against JPA principles:)
    So is there a newer version of JPA that fixes this issue?
    I couldn’t find this problem mentioned anywhere else.
    Does Oracle/Sun know about this issue to fix in their next version?
    would you know?

    • http://www.mkyong.com mkyong

      I just found this conflict few months ago, may be you can ask this question in Hibernate forum

  • Pingback: Hibernate Tutorials | Tutorials()

  • Edmund Leng

    I thought you should be using EntityManager which is created to solve problems of such nature.

    • http://www.mkyong.com mkyong

      yes for this info, but some projects may not want to couple the JPA engine.

  • Maarten

    CascadeType.PERSIST will work when using session.persist() instead of session.save()

    • roshi

      Thanks for that tip saved the mixing up of hibernate annotations with jpa