java - JPA Collection of objects with Lazy loaded field -

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what way force initialization of lazy loaded field in each object of collection?

at moment thing comes mind use for each loop iterate trough collection , call getter of field it's not effiecient. collection can have 1k objects , in case every iteration fire db.

i can't change way fetch objects db.

example of code.

public class transactiondata{  @manytoone(fetch = fetchtype.lazy) private customerdata customer; ... }  list<transactiondata> transactions = gettransactions();

you may define entity graphs overrule default fetch types, defined in mapping.

see example below

@entity @namedentitygraph(     name = "person.addresses",      attributenodes = @namedattributenode("addresses") ) public class person {     ...     @onetomany(fetch = fetchtype.lazy) // default fetch type     private list<address> addresses;     ... }

in following query adresses loaded eagerly.

entitygraph entitygraph = entitymanager.getentitygraph("person.addresses"); typedquery<person> query = entitymanager.createnamedquery("person.findall", person.class); query.sethint("javax.persistence.loadgraph", entitygraph); list<person> persons = query.getresultlist();

in way able define specific fetch behaviour each differet use-case.

see also:

by way: afaik jpa provider perform eager loading of @xxxtoone relations, if define mapping lazy. jpa spec allow behaviour, lazy loading hint data may or may not loaded immediately. eager loading on other other hand has performed immediately.


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