RegExp使用大括号格式化json字符串

我有一个json对象，如下所示，首先基于属性user_id和acct_id的值搜索用户和帐户，然后将desc格式化为完整的句子，例如“Mary创建储蓄帐户”或“Peter转账到John借记帐户” 我完成了搜索部分，并正在处理字符串格式。 因为我对ES不是很熟悉，所以我想确保我走上了正确的道路。我应该使用regexp来执行此操作吗？或者ES有一些我可以使用的功能

{  
   "transactions":[  
      {  
         "created_at":"2017-06-24T16:30:40+10:00",
         "desc":"{ user:4321 } creates { acct:1357 }",
         "act":"create",
         "acct_id":1357,
         "user_ids":[  
            4321
         ]
      },
      {  
         "created_at":"2017-06-24T16:30:40+10:00",
         "desc":"{ user:2456 } transfers to { user:7890 }{ acct:0987 }",
         "act":"transfer",
         "acct_id":9870,
         "user_ids":[  
            2456,
            7890
         ]
      }
   ],
   "users":[  
      {  
         "id":4321,
         "name":"Mary"
      },
      {  
         "id":2456,
         "name":"Peter"
      },
      {  
         "id":7890,
         "name":"John"
      }
   ],
   "accounts":[  
      {  
         "id":1357,
         "usder_id":4321,
         "type":"Saving Account"
      },
      {  
         "id":9870,
         "usder_id":7890,
         "type":"Debit Account"
      },
      {  
         "id":4234,
         "usder_id":7890,
         "type":"Credit Account"
      }
   ]
}