DataTableRepository in Spring data Elasticsearch

spring-data-jpa-datatables does not implement support for ElasticsearchRepository, as you say and use the Specification API which is not implemented by Spring Data for Elasticsearch, so extending it would take some work.

What you need to do is create your own ElasticsearchRepositoryFactoryBean (ie. ElasticsearchDataTablesRepositoryFactoryBean) and your own implementation of AbstractElasticsearchRepository that implements the specifics of spring-data-jpa-datatables just like DataTablesRepositoryImpl. You should also define your own DataTablesRepository (ElasticsearchDataTablesRepository that extends ElasticsearchRepository) with the same methods.

The org.springframework.data.jpa.datatables.mapping classes can be reused, but you'll have to recreate the logic found in SpecificationFactory for elasticsearch using QueryBuilders, which will be the most time consuming part I imagine.

When you're done, you can use the @EnableElasticsearchRepositories just like described by spring-data-jpa-datatables ie.:

@EnableElasticsearchRepositories(repositoryFactoryBeanClass = ElasticsearchDataTablesRepositoryFactoryBean.class))

And extend your repositories with your ElasticsearchDataTablesRepository interface and you're good to go.

For reference you should look at SpecificationFactory and AbstractElasticsearchRepository (the search method) and get familiar with Elasticsearch QueryBuilders.