I found that CommentRequest has author property but even if set value not seem to save database. Please tell me how to set comment author when use rest api. Also AttachmentRequest how to set value of ACT_HI_ATTACHMENT 's user id field when use rest api.
That seems indeed to be the case, the data is simply ignored. This would need changing in the TaskCommentCollectionResource. Would you be able to create a pull request for this that fixes it?