Is it possible to write rest APIin java without username and password?

[Ramesh Lakshmanasamy]

I want create rest API in java.but when i write rest that time show 400 request.i already in (same URL) jira.Then why  need to give username and password.

[Mirek]

That is because REST API respect user permission. You cannot get data via REST API that you are not allowed to see using standard UI session. If you have anonymous JIRA access maybe that would be possible. Then all can see data without application access.