java - Cannot load data from DynamoDB due to an attribute of type List<Object> which is not able to get unconverted and was saved using @DynamoDBDocument -

i trying save list<customobject> using @dynamodbdocument gives me dynamodbmappingexception : not unconvert attribute.

here entity class looks -

@lombok.data @dynamodbtable(tablename = "cartable") public class car {    @dynamodbhashkey(attributename = "name")    private carname;     @dynamodbrangekey(attributename = "model")    private carmodel;     @dynamodbattribute(attributename = "manufacturers")    private list<manufacturer> manufacturers; } 

the manufacturer class looks -

@lombok.data @dynamodbdocument public class manufacturer {     @dynamodbattribute     private string manufacturername; } 

when using entity , saving values table saves json, when retrieving it, exception thrown -

com.amazonaws.services.dynamodbv2.datamodeling.dynamodbmappingexception: car[manufacturers]; not unconvert attribute @ com.amazonaws.services.dynamodbv2.datamodeling.dynamodbmappertablemodel.unconvert(dynamodbmappertablemodel.java:271) [junit]     @ com.amazonaws.services.dynamodbv2.datamodeling.dynamodbmapper.privatemarshallintoobject(dynamodbmapper.java:456) [junit]     @ com.amazonaws.services.dynamodbv2.datamodeling.dynamodbmapper.load(dynamodbmapper.java:422) [junit]     @ com.amazonaws.services.dynamodbv2.datamodeling.dynamodbmapper.load(dynamodbmapper.java:433) [junit]     @ com.amazonaws.services.dynamodbv2.datamodeling.abstractdynamodbmapper.load(abstractdynamodbmapper.java:85) 

what missing here, need add sort of typeconverter or marshaller here?

i don't think need custom converter here, looks dynamodb has issues converting dynamodb item java object.

check:

• data in dynamodb matches object fields. check if types matching well

• what if define setters explicitly? maybe lombok culprit here?

also odd not specify table name here:

@dynamodbtable(tablename) public class car { ... }