Error: DynamoDB Mapper Could Not Instantiate Class
Answered by Rafal Wilinski
What's Causing This Error
When working with DynamoDB Mapper, if the program is trying to map an object to a DynamoDB table but cannot instantiate the class that represents the object, then this error can arise. Alternatively, it may be because the class you're trying to map to the DynamoDB table has a constructor with parameters.
Solution: Here's How To Resolve It
To resolve this error, check and verify that the class has a default constructor and is on the classpath. In addition, if the class you are trying to map to the DynamoDB table has a constructor with parameters, you have to use DynamoDBMapperConfig.Builder.withSaveBehavior(DynamoDBMapperConfig.SaveBehavior.UPDATE_SKIP_NULL_ATTRIBUTES).
Ensure that the class is available on the classpath along with all its dependencies, and ensure the class has correct annotations and they are in the right package.
Other Common DynamoDB Errors (with Solutions)
- DynamoDB GetItem no item
- dynamodb-admin command not found
- DynamoDB Update Not Working
- AWS DynamoDB errors ResourceNotFoundException
- dynamodb list_append returns true but does not work
- ProvisionedThroughputExceededException DynamoDB
- One or more parameter values were invalid: some AttributeDefinitions are not used
- is not authorized to perform dynamodb:* on resource
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- dynamodb cannot convert undefined to object
- accessdeniedexception dynamodb
- DynamoDB ConditionalCheckFailedException
- DynamoDB Duplicate Key Error
- DynamoDB scan does not return all items
- DynamoDB batch write is not working