Ant build with JDK-8 only

[CCI_SINGHNI]

I want use bit-bucket pipelines for build an Ant Project along with JDK-8 only. How will the yml file look like?

I have 2 cases -

1) First workspace, I will do entire build of the master with is easy.

2) In second workspace, based on last commit; I need to find the package and build only those packages which should be part of 2nd build. How to I pass this logic dynamically for build.xml as argument here automatically?

If it seems to be difficult, I can migrate  from Ant to Gradle, if its simple to write and maintain.

Can you guys please help or suggest?