Persisting a Map<String,String> in ORMLite without resorting to DataType.SERIALIZABLE?

Question

I've got a relatively simple class that is primarily backed by a Map<String,String>. I'd like to persist this class and be able search within the keys within the map. Based on this Stack Overflow question I get the feeling that Maps can only be persisted as a serialized blob.

I also see on the ORMLite website the following:

public class Account {
    …
    @ForeignCollectionField(eager = false)
    ForeignCollection<Order> orders;
    …
}

In the above example, the @ForeignCollectionField annotation marks that the orders field is a collection of the orders that match the account. The field type of orders must be either ForeignCollection or Collection<T> - no other collections are supported. The @ForeignCollectionField annotation supports the following fields:

Based on the above I get the impression that what I want isn't possible, but I thought I'd check here to be sure. I have it persisted in Hibernate, but I'd rather use something lighter like ORMLite!

Answer 1

One pretty easy solution is to have the getters and setters work with a JSONObject behind the scenes, and putting that object as a String in the database.

But then again, JSON isn't part of java-out-of-the-box so this may feel unneccesary if you're not using it anyway.

Answer 2

Yeah, there is no way in ORMLite to persist a Map. Keeping with the KISS principle, only the simple Collection class is supported. Set and Map have a lot more interface weight to them and will probably never be supported.

I don't have any super great work arounds for you. You could obviously use ForeignCollection and then have a local Map field that you create when you need to access the collection that way. Maybe an addOrder() method that would add it to the ForeignCollection and the Map.