How to add Comment or Likes on activity

 Hi all,

 I need to add comment or likes on activity in webcenter spaces using REST API.

 I execute a post method to the following url. But it failed. Please refer to my attachment. Can anyone tell me how to realize this function with REST API.

http://cdcjp77vm3.cn.oracle.com:8888/rest/api/activities/services/oracle.webcenter.community/objectTypes/groupSpace/objects/(s2907f474_02c3_4c7b_963e_84ccbf907348)/likes?startIndex=0&itemsPerPage=10&utoken=FDNA-Z7ekZuPnVSNoPWOqTJ2IzAE_w**

Thanks

Qian