I need to Customize the serializer in ember.js Adapter

My server needs json in the below format when sending a PUT request. My server is a rest api designed using struts2 rest plugin.

{
id: "5",
empId: "5",
firstName: "oki", 
lastName: "iko", 
edQual: "phd"
}
but the RESTAdapter serializes it to
[
employees:
 {
  id: "5", 
  empId: "5", 
  firstName: "oki", 
  lastName: "iko",
  edQual: "phd"
 }
]

I tried ignoring properties in backend but that just ignored the whole json and submitted null values to the sql-server. I need to override or customize the Serialization of ember.js but I dont know how.