HttpAPI.java

 @PostMapping("/HttpTriggerWithOutputs")
public InvokeResponse HttpTriggerWithOutputs(){
  InvokeResponse resp = new InvokeResponse();
  resp.ReturnValue = "return val data here";

  Map<String, Object> headers = new HashMap<String, Object>();
  headers.put("header1", "header1Val");
  headers.put("header2", "header2Val");

  Map<String, Object> httpRes = new HashMap<String,Object>(); 
  httpRes.put("statusCode", "201");
  httpRes.put("body", "my world");
  httpRes.put("headers", headers);

  resp.Outputs.put("res", httpRes);
  return resp;
}