[#BSHD-8] OutOfMemoryError on findFiltered( ) with bi-directional one-to-many relationship - OpenmindLAB JIRA

Base spring/hibernate DAO

OutOfMemoryError on findFiltered( ) with bi-directional one-to-many relationship

Created: 28/Jul/10 22:48 Updated: 25/Aug/10 08:13 Resolved: 25/Aug/10 08:08

Component/s:

None

Affects Version/s:

2.0.5

Fix Version/s:

2.1.0

File Attachments:	1. StackTrace.txt (3 kB) 28/Jul/10 22:48 - Scott Rainaldo
Environment:	Windows XP, Eclipse 3.5, Java 6 JRE

Description

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I am getting an OutOfMemoryError upon executing a findFiltered( ) query with a bi-directional one-to-many Hibernate relationship. The stack trace is attached. It seems the code is in an infinite loop due to the circular references.

Here is an example of the relationship:

class Parent { private Long id; private Set<Child> children; ... other fields and code }

class Child { private Long id; private Parent parent; // needed for foreign key relationship ... other fields and code }

Test code:

public Parent findByChildren(Set<Child> children)

{ Parent parent = new Parent(); parent.setChildren(children); bshd5DAO.findFiltered(parent); // OutOfMemoryError here }

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Gabriele Catania added a comment - 24/Aug/10 22:24 - edited

This is a known issue in the current EnhancedExample implementation. What happens in your case is:

when the parent object is processed, each of its writeable properties (identified by the presence of setter methods) are examined
each property whose type is non-trivial (i.e. not one of string, simple type) and value is non-null (or not empty in case of collections) is processed recursively. In your case, the children property of type Set<Child> is found with a non-empty value and processed
each property of the child object is examined: a parent property of nontrivial type is found and processed, so we're back to step one.

I am afraid with the current implementation, you need to adopt one of the following workarounds:

rename the setter method of the parent property of Child to a nonstandard name (e.g. updateParent()) so that it is not recognized as a writeable property by the recursive method
remove the setter method on the parent property of Child altogheter

This is one of the limitations of the current implementation and will be resolved on the next release.