java - Is there a better way to persist a map with the value being a set? -

java - Is there a better way to persist a map with the value being a set? -

i'm looked lot beingness able utilize hibernate persist map map<string, set<entity>> little luck (especially since want on 1 table).

mapping multimaps hibernate thing seems referenced most, describes in detail how go implementing using usercollectiontype.

i wondering, since written on 4 years ago, there improve way of doing now?

so, example, have on entitya map map<string, set/list<entityb>>.

there 2 tables: entitya , entityb (with entityb having foreign key entitya).

i don't want intermediate tables.

the way how done on current project transforming beans/collections xml using xstream:

public static string toxml(object instance) { xstream xs = new xstream(); stringwriter author = new stringwriter(); xs.marshal(instance, new compactwriter(writer)); homecoming writer.tostring(); }

and using lob type in hibernate persisting :

@lob @column(nullable = false) private string data;

i found approach generic , implement flexible key/value storage it. you don't xml format xstream framework has inbuilt driver transforming objects json. give try, cool.

cheers

edit: response comment. yes, if want overcome limitations of classic approach sacrifice indexing and/or search. stil implement indexing/searching/foreign/child relationships thru collections/generic entity beans - maintain separate key/value table property name/property value(s) think search needed.

i've seen number of database designs products flexible , dynamic(i.e. creation new attributes domain objects without downtime) schema needed , many of them utilize key/value tables storing domain attributes , references owner objects kid one. products cost millions of dollars (banking/telco) guess design proven effective.

sorry, that's not reply original question since asked solution without intermediate tables.

java hibernate map