DynamoDB Storing/ Mapping Complex Objects in Maps

Question

We are trying to get started with dynamo db and I'm breaking my head over a mapping problem.

I have a model Match and matchPlayer.

Match has a map property which contains matchPlayer objects.

I can't get dynamodb to correctly map this property. I tried the json Marshaller but that just results into an error

Expected S in value {M: {player2={M:(More json)

Are there any good examples or tutorials for mapping/ marshalling a map with complex objects to work with dynamodb? I found tutorials for working with simple complex objects but not with a map of objects.

I'm glad for any help!

@DynamoDBTable(tableName="Matches")
public class Match {

    private String matchId;
    private Boolean active;
    private int currentRound;
    private Boolean finished;

    private Map<String, MatchPlayers> players;

    @DynamoDBHashKey(attributeName = "matchId")
    public String getMatchId() {
        return matchId;
    }

    public void setMatchId(String matchId) {
        this.matchId = matchId;
    }
    @DynamoDBIndexRangeKey(attributeName = "active")
    public Boolean getActive() {
        return active;
    }

    public void setActive(Boolean active) {
        this.active = active;
    }


    @DynamoDBIndexRangeKey(attributeName = "currentRound")
    public int getCurrentRound() {
        return currentRound;
    }

    public void setCurrentRound(int currentRound) {
        this.currentRound = currentRound;
    }

    @DynamoDBIndexRangeKey(attributeName = "finished")
    public Boolean getFinished() {
        return finished;
    }

    public void setFinished(Boolean finished) {
        this.finished = finished;
    }

    @DynamoDBMarshalling(marshallerClass = MatchPlayersMarshaller.class)
    @DynamoDBIndexRangeKey(attributeName = "players")
    public Map<String, MatchPlayers> getPlayers() {
        return players;
    }

    public void setPlayers(Map<String, MatchPlayers> players) {
        this.players = players;
    }
}

Answer 1

The DynamoDB Object Mapper for Android currently does not support complex data type mapping for the array and map. You need to manually map a dictionary to a custom object for yourself.