What elasticsearch version does Spring boot 1.5.9 support?

java elasticsearch spring-boot versioning spring-data-elasticsearch

answering your questions:

Unfortunately the spring data elasticseach 3.X requires the Spring Boot 2.X (see also this answer: Elasticsearch 5.x Repository Java Spring Boot)
With Spring Boot 1.X you could use latest 2.X spring data elasticsearch and with that you could use Elasticsearch 2.X.X version in this case.

I assume that you are aware that there is no 3.X and 4.X version of Elasticsearch - from versioning reasons they moved from 2.X to 5.X.

CodeHunter