Unable to add checklist via Java API

Looking at your JSON, the only things you are missing are the " " around the reviewId and your second parameter should be "checklistId".

Here's an exmaple of the code snippet I ran on my local server to add checklist #2 to my review #449:

[{"command" : "SessionService.authenticate",
   "args" : {
      "login" : "xxxxxxx",
      "ticket" : "xxxxxxxxxxxxxxxxx"
      }
},
{"command" : "ReviewService.addChecklist",
   "args" : {
      "reviewId" : "449",
      "checklistId" : "2"
      }

}]

My review before executing this command shows checklistId #1 (Development Checklist) available on the review.

Executing the JSON detailed above adds the second checklist (#2 - Cross Team Communication) to that same review:

Please note that the checklists you want to add through the JSON API must be available to the template in use on that particular review.

Cheers,

Mel