jpa - How do I lazy load a nested collection? -

i have entity parent , relation @onetomany entity child. collection children set lazy loading.

@entity class parent{     @id     string parentid;     @onetomany(mappedby="parent",fetch=fetchtype.lazy)     list<child> children; }  @entity class child{     @id     string childid;     @manytoone     @joincolumn(name="parentid")     parent parent; }  list<parent> loadparents() {     qparent qparent = qparent.parent;     list<parent> parentlist = query.select(qparent).from(qparent).fetch();     return parentlist; }  @transactional void test(){     list<parent> parentlist = loadparents();     for(child child:parentlist.getchildren()){         child.getchildid();     } } 

i famous

org.hibernate.lazyinitializationexception: failed lazily initialize collection of role ... not initialize proxy - no session

exception in test() method on line access children list.

i don't want change fetch type annotation in entity.

how access child entities?

i found culprit. transaction management disabled.

the @transactional annotation missing test method.

to enable transaction management, put in application-context.xml:

<tx:annotation-driven /> 

there nothing wrong code, configuration incomplete. eagerly load nested collections need embracing transaction.

turning on debug logging org.springframework.orm , org.hibernate helped me identify source of issue.

similar question , answer: lazyinitializationexception in jpa , hibernate