Store enum collection in database using ORMLite

Question

I'm trying to save enum collection in database with ORMLite. So while creating Dao I'm getting no-args constructor error

I have tried create default package contructor, but it doesn't helps - I think ORMLite requires public constructor, but enums cannot have it.

My enum looks like this (separated .java file)

enum RankPermission {
  @DatabaseField(dataType=DataType.ENUM_TO_STRING)
  ALL,
  //...
  ;

  RankPermission() {}
}

And collection in another class is

@DatabaseTable
class Rank {
  @ForeignCollectionField
  Collection<RankPermission> permissions;

  public Rank() {}
}

Dao creation and error which I have got

DaoManager.createDao(conn, Rank.class);

        [23:31:12 ERROR]: Can't find a no-arg constructor for class package.core.rank.RankPermission
        java.lang.IllegalArgumentException: Can't find a no-arg constructor for class package.core.rank.RankPermission
        at com.j256.ormlite.table.DatabaseTableConfig.findNoArgConstructor(DatabaseTableConfig.java:229) ~[?:?]
        at com.j256.ormlite.table.DatabaseTableConfig.getConstructor(DatabaseTableConfig.java:154) ~[?:?]
        at com.j256.ormlite.table.TableInfo.<init>(TableInfo.java:96) ~[?:?]
        at com.j256.ormlite.table.TableInfo.<init>(TableInfo.java:54) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.initialize(BaseDaoImpl.java:156) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.<init>(BaseDaoImpl.java:133) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.<init>(BaseDaoImpl.java:112) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl$5.<init>(BaseDaoImpl.java:1044) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.createDao(BaseDaoImpl.java:1044) ~[?:?]
        at com.j256.ormlite.dao.DaoManager.createDao(DaoManager.java:70) ~[?:?]
        at com.j256.ormlite.field.FieldType.configDaoInformation(FieldType.java:392) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.initialize(BaseDaoImpl.java:206) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.<init>(BaseDaoImpl.java:133) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.<init>(BaseDaoImpl.java:112) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl$5.<init>(BaseDaoImpl.java:1044) ~[?:?]
        at com.j256.ormlite.dao.BaseDaoImpl.createDao(BaseDaoImpl.java:1044) ~[?:?]
        at com.j256.ormlite.dao.DaoManager.createDao(DaoManager.java:70) ~[?:?]
        at package.storage.yaml.db.DatabaseConnector.initDaos(DatabaseConnector.java:152) ~[?:?]

I would like to save this collection in enum form, beacause it is more comfortable

Answer 1

To solve this problem I've just used any Collection from java.util package and set @DatabaseField(dataType=DataType.SERIALIZABLE) annotation instead of @ForeignCollectionField to save serialized data, so now code is

class Rank {
    @DatabaseField(dataType=DataType.SERIALIZABLE)
    private HashSet<RankPermission> permissions = new HashSet<>();
}

It's important to set HashSet type to field, because ORMLite will not detect serializable interface on Set .