hibernate - JPA and "anonymous" classes in scala -


i'm bit stuck , don't understand what's going on. 1 doesn't work

@entity @dynamicinsert @dynamicupdate @selectbeforeupdate @table class entity {   @column(nullable = false)   var owner: string = _ }       val myentity = new entity() {             owner = "some owner 1"           }       session.persist(myentity)

hibernate throws exception:

java.lang.illegalargumentexception: unknown entity:persistence.dao.entitydaotest$$anonfun$13$$anonfun$14$$anon$5     @ org.hibernate.internal.sessionimpl.firepersist(sessionimpl.java:777)

this 1 works:

val myentity = new entity() entity.owner = "some owner 1" session.persist(myentity)

why? why hibernate don't recognize entity instance?

upd: @sheinbergon, thanks, it's clear. forgot annotations lost. there possibility set entity fields shortcut? writing

val myentity = new myentity() myentity.owner = "some owner" myentity.someotherproperty = "value"

is super boring

one more question 1 works:

val parent = new parent     parent.owner = "our parent"     parent.addchild(new child() {       name = "first parent's child"       addgrandchild(new grandchild() {         name = "grand child name"         addgrandgrandchild(new grandgrandchild() {           name = "grand grand child name"           address = new address() {             id = 1l           }         })       })     })

why? child, grandchild, grandgrandchild created anonymously. addchild, addgrandchild, addgrandgrandchild list mutators.

def addchild(child: child): unit = {     if (children == null) {       children = new util.arraylist[child]()     }     if (option(child.parent).isempty) {       child.parent =     }     children.add(child)   }

what doing here instantiating class anonymously in scala , , well... creates anonymous implementation of class entity ( instantiating interface anonymously in java).

you can see printing class name - println(myentity.getclass) in both cases

annotations applied original class not apply anonymous 1 (reflection can still find them in super class, that's code scanning them) , guess that's why you're getting various jpa exceptions

in response added sub-questions

  • regarding shortcut - why don't use companion objects factories or turn class case class (with defaults), allowing nicer, more flexible initialization.
  • regarding second object graph(and assuming eachof classes annotated) - again depends on how reflective code treats objects scans. it's possible ( , more likely, given won't scan each member of collection annotations ) takes annotation definitions erased type ( possible it's fqdn class name parameterizedtype in java's reflection api) of collection , not actual members of collection , that's why works. i'm not sure field definitions though (they present in "super" class), there's no "magic" here, plain old reflection scans.

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