DynamoDB XSPEC SDK for Java SDK 2.0

[iamrohitbanga]

Describe the feature

AWS Java SDK v1 supports DynamoDB xspec API.
Blog here: https://aws.amazon.com/blogs/developer/dynamodb-xspec-api/

Can't find the equivalent in aws-sdk-java-v2 code base.

Is your Feature Request related to a problem?

The XSPEC API offers a convenient layer on top of DynamoDB. Nice to have.

Proposed Solution

Add relevant code from here and here to SDK 2.0 or provide another package that may wrap on top of the low level SDK.

Describe alternatives you've considered

No response

Acknowledge

• I may be able to implement this feature request

AWS Java SDK version used

2.0

JDK version used

Java 11

Operating System and version

All

[debora-ito]

Hi @iamrohitbanga ,

Did you take a look at the DynamoDB Enhanced Client? It would be its equivalent in Java SDK v2.

Just like the XSpec API, the DynamoDB Enhanced Client is a high-level library built on top of the DynamoDB API operations, and it also provides easy to use query Expressions.

Some references:

• https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/dynamodb-enhanced-client.html
• https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/examples-dynamodb-enhanced.html

Blog posts:

• https://aws.amazon.com/blogs/developer/introducing-enhanced-dynamodb-client-in-the-aws-sdk-for-java-v2/

Let us know what you think.

[iamrohitbanga]

Hi Debora,

Thanks for your reply. The closest example for building expressions that I can find in the docs is:

            AttributeValue att = AttributeValue.builder()
                    .s("sblue@noserver.com")
                    .build();

            Map<String, AttributeValue> expressionValues = new HashMap<>();
            expressionValues.put(":value", att);

            Expression expression = Expression.builder()
                    .expression("email = :value")
                    .expressionValues(expressionValues)
                    .build();


            // Create a QueryConditional object that is used in the query operation.
            QueryConditional queryConditional = QueryConditional
                    .keyEqualTo(Key.builder().partitionValue("id103")
                            .build());

The XSPEC API would let me do the same with much less code and was more convenient - specifically I did not have to worry about creating placeholders for expressionValues or expression attribute names. Example for the same below:

        Condition keyCondition = ExpressionSpecBuilder.S("partitionKey").eq("id103");
        Condition condition = ExpressionSpecBuilder.S("email").eq("sblue@noserver.com");

        var builder = new ExpressionSpecBuilder();
        QueryExpressionSpec queryExSpec = builder.withCondition(condition).withKeyCondition(keyCondition).buildForQuery();
        QuerySpec spec = new QuerySpec().withExpressionSpec(queryExSpec);

Note that I do not have to create NameMap or expressionValues map explicitly with XSPEC which seems like a useful feature for me - esp because then we don't have to worry about using DynamoDB reserved words. Additionally it the expression builders with their static seems more programmer friendly than string queries. I don't see the equivalent in the 2.0 API. May be I am missing something?

[amoscatelli]

It seems a proper query/expression builder is missing from the v2 sdk.
This is no good.

[amoscatelli]

https://aws.amazon.com/it/blogs/developer/dynamodb-xspec-api/

This is what I expected to be able to do.

[debora-ito]

Quick update: we've added this to our backlog.

For anyone tracking this issue, please add a 👍 in the original description to show your support, it helps us with prioritization.