java - ManyToMany mapping to include some extra records -

let's have following model:

@entity public class user {      ...      @manytomany     private set<permission> allowedpermissions;      ...  }    @entity public class permission {      ...      private boolean isdefault;      ...  } 

is possible map user.allowedpermissions contains both permissions connected user , these isdefault = true not explicitly connected?

i use hibernate jpa provider.

well not possible because don't have enough information permissions in user.

if think @ many-to-many relationship, on database it's relation table between 2 other tables.

now, in user entity you're correctly using set see relations stored in cross table (let's user_permission). @ level you're not able know default permissions, can retrieved via permissiondao (i assume you're using dao/service design, if not adjust needs).

if want superset (allowedpermissions + defaultpermissions), can maybe write utility method @ service layer if like:

getallpermissions(user user) {    return userdao.getallowedpermissions(user).addall(permissiondao.getdefaultpermissions());  } 

why @ service layer? because need 2 daos @ same time, , don't want inject dao another. let me know if useful.