Doma external embeddable

Era.java

@Entity
public class Era {

  @Id
  public Integer id;

  public String name;
  
  public Interval interval;
}

era.sql

create table era {
  id integer primary key,
  name varchar(100),
  start bigint,
  end bigint,
}

IntervalAdapter.java

@Embeddable
public class IntervalAdapter {

  private final long start;
  private final long end;

  public IntervalAdapter(long start, long end) {
    this.start = start;
    this.end = end;
  }
  
  // getter, setter
}

IntervalConverter.java

@ExternalEmbeddable
public class IntervalConverter implements EmbeddableConverter<Interval, IntervalAdapter> {

  public IntervalAdapter fromEmbeddableToAdapter(Interval interval) {
    return new IntervalAdapter(interval.getStartMillis(), interval.getEndMillis());
  }

  public Interval fromAdapterToEmbeddable(IntervalAdapter adapter) {
    return new Interval(adapter.getStart(), adapter.getEnd());
  }
}