java - annotation mapping bidirectional OneToMany/ManyToOne not fetching? -

i'm struggling understand appreciated...

i have following mapping:

@entity @table(name = "parent") public class parententity { ...     @id     @column(name = "parent_id")     private long id; ...     @onetomany(mappedby = "parent", fetch = fetchtype.eager)     private list<childentity> children; ... }  @entity @table(name = "child") public class childentity { ...     @id     @column(name = "child_id")     private long id; ...     @manytoone(fetch = fetchtype.eager)     @notfound(action = notfoundaction.ignore)     @joincolumn(name = "parent_id")     private parententity parent; ... } 

in db have:

parent ------ parent_id: 1  child ------ child_id: 1, parent_id: 1 

however

((parent) session.get(parent.class, 1)).getchildren() 

returns null.

can see have missing?

thanks, p.

edit

it seems more-so session state in collection not populated in context of same session, collection populated in next session...

consider following:

void setuprender() {     debug("existing not added", (parententity) session.get(parententity.class, 13l));      parententity parent = new parententity();     session.save(parent);      childentity child = new childentity();     child.setparent(parent);     session.save(child);      debug("new 1 before commit", parent);      sessionmanager.commit();      debug("new 1 after commit", parent);      debug("new 1 after re-fetch", (parententity) session.load(parententity.class, parent.getid())); }  private void debug(string prefix, parententity parent) {     log.debug(prefix + ": parent id: " + parent.getid() + ", children "             + (parent.getchildren() == null ? "null" : "size:" + parent.getchildren().size())); } 

results in following output:

debug - existing not added: parent id: 13, children size:1 debug - new 1 before commit: parent id: 23, children null debug - new 1 after commit: parent id: 23, children null debug - new 1 after re-fetch: parent id: 23, children null 

so if it's due session state, , commit isn't enough trigger re-fetch, have mapping fetch collection?

thanks again!

yes, commit doesn't trigger refresh of session cache.

the typical approach here use session-per-request pattern, close session after commit, , open session following transactions (though it's not option if use open session in view pattern).

another practice may solve problem modify both sides of bidirectional relationship simultaneously:

public class parententity {     ...     public void addchild(childentity c) {         children.add(c);         c.setparent(this);     } } 

this way can keep objects in session cache in consistent state.

finally, if need refresh object inside session can call session.refresh() on it.