[OPENJPA-286] Can't merge detached One-To-Many child instance. The entities were implement by an internal Hash container.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.7, 1.0.0, 1.1.0
• Fix Version/s: 1.2.0
• Component/s: jdbc
• Environment: java version "1.5.0_10"; Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_10-b03); Java HotSpot(TM) Client VM (build 1.5.0_10-b03, mixed mode, sharing)
• Assignee: Pinaki Poddar
• Reporter: Gene Wu
• Created: 19/Jul/07 10:11
• Updated: 09/Mar/10 18:32
• Resolved: 16/Jul/08 04:50

Description

Maybe you know, one of the entity implementation is composite of a hash set, which stores key-value pairs.

It's a common design of Entity Bean in EJB2.x ages. Does any one use it in OpenJPA? I am using it right now, and encounter an issue in entity cascade manipulate. Here is the issue description.

Base.java : the super class of entities.
protected final Object getAttributeValue(String attributeName)

{ return _values.get(attributeName); }

protected final void setAttributeValue(String attributeName, Object value)

{ _values.put(attributeName, value); }

// To hold the

{attributeName, value}

pair of the value object.
private HashMap<String, Object> _values = new HashMap<String, Object>();

C.java extends Base.java : Entity C has a set of Entity D.
public void setDs(Set<D> ds)

{ setCollection("Ds", ds); }

@OneToMany(mappedBy = "c", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
public Set<D> getDs()

{ return (Set<D>)getAttributeValue("Ds"); }

D.java extends Base.java as well.

The relationship between C and D is one-to-many. I use following code to reproduce the issue.

C c = em.find(C.class, 1);
logger.debug(c.getDs().size());
D d = new D();
d.setC(c);
c.getDs().add(d);
em.merge(c);

After commit the transaction, you will find the new D instance was not inserted into the database(there is no insert sql log as well). After you add, em.persist(c). That new instance will be added!

Meanwhile, I wrote a couple of classes, which do not use a HashSet. I got the expected result after merge is done.