Chang the project issue status

I want to developer a plugin to copy an project issue to anther projet in jira ,now I can copy some fields but not the status.It doesn’t work by Issue.setStatus(status) and I have no idea to get the actionid through Issue Object .I konw that we can change the status through the rest api,But can we change the project issue’s status without rest api in a plugin? Thank you very much for anyone can help me,thank you!