in my workspace i created multiple repositories how can create jar files from each and every reposit

[Nallamothu Kiran Raj]

In each and every repository have java project, previoulsy i did manually and created Jar, now how can i get jar dynamically with setup a pipeline?

[Aron Gombas _Midori_]

For your other question, I suggested using Maven. That is my recommendation (and pretty much the defacto standard) here as well.

Atlassian has a nice guide here to help get you started: https://support.atlassian.com/bitbucket-cloud/docs/java-with-bitbucket-pipelines