Hibernate @ManyToMany problem

[Alexandr.Kormiltsyn]

Hello.
I have 3 tables in DB. 2 for entities and one for the relations between them. I have 2 java classes:

	private static final long serialVersionUID = 1L;

	@Id
	@SequenceGenerator(name = "treatment_code_id_seq", sequenceName = "treatment_code_id_seq", allocationSize = 1)
	private long id;

	@Column(name = "code")
	private String code;

	@Column(name = "description")
	private String description;


	@ManyToMany(cascade = CascadeType.ALL)
	@JoinTable(name = "category_code_relation", joinColumns = @JoinColumn(name = "code_id"), inverseJoinColumns = @JoinColumn(name = "category_id"))
	private List<CPTCodeCategory> categories;
...

WHen I try to call a controller method:

treatmentCode.getCategories()

I receive the hibernate exception:

ERROR: org.hibernate.LazyInitializationException - failed to lazily initialize a collection of role: org.mbs.billing.model.cpt.TreatmentCode.types, no session or session was closed
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.mbs.billing.model.cpt.TreatmentCode.types, no session or session was closed
	at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:358)
	at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:350)
	at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:343)
	at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:86)
	at org.hibernate.collection.PersistentBag.toString(PersistentBag.java:483)
	at java.lang.String.valueOf(String.java:2826)
	at java.io.PrintStream.println(PrintStream.java:771)
	at org.apache.tomcat.util.log.SystemLogHandler.println(SystemLogHandler.java:269)
	at org.mbs.billing.controller.roadmap.impl.PhaseCompositionHelperImpl.getCategoryList(PhaseCompositionHelperImpl.java:307)
	...

As I understand the problem with initialization the list. What may be wrong here?

Thank you in advance.

[zakhrim]

I have exactly the same problem.
Hibernate session is closed when accessing the collection. The workaround is to set

@ManyToMany(cascade = CascadeType.ALL, fetch=FetchType.EAGER)

but this is not a solution.
I encountered the same problem when managing Hibernate by myself, I thought SpringRoo managed these issues by himself.

Is there a solution?

PS: I'm using Roo 1.1.5, STS 2.8.1

Thanks,
Stefano