Hello Team,
 I have json data of account and contact and want to insert the same into the salesforce, So I have made Restapi using wrapper class method.I am pasting JSON data, apex class.Please let me know what more things i need to change in my code.

Json data:-
{
  "accountList": [
    {
      "Name": "testPlC",
      "ActivationDate": "2011-10-04T16:58:54.858Z",
      "ContactItems": [
        {
          "FirstName": "PLCTest",
          "LastName": "plsignore",
          "Birthdate": "2011-10-04"
        },
        {
          "FirstName": "PLCTestv2",
          "LastName": "plsignorev2",
          "Birthdate": "2011-10-04"
        }
      ],
      "AccountNumber": "001"
    },
    {
      "Name": "testPlCV2",
      "ActivationDate": "2011-10-05T16:58:54.858Z",
      "ContactItems": [
        {
          "FirstName": "PLCTestv3",
          "LastName": "plsignore",
          "Birthdate": "2011-10-04"
        },
        {
          "FirstName": "PLCTestv4",
          "LastName": "plsignorev2",
          "Birthdate": "2011-10-04"
        }
      ],
      "AccountNumber": "002"
    }
  ]
}
Json class:-

public class JSON2Apex {
    public class AccountList{
        public String Name;
        public Date ActivationDate;
        public String AccountNumber;
        public List<ContactItems> ContactItems;   
    }
    public class ContactItems{
        public String FirstName;
        public String LastName;
        public String Birthdate;    
    }
    public List<AccountList> accountList;
    public static JSON2Apex parse(String json){
        return (JSON2Apex) System.JSON.deserialize(json, JSON2Apex.class);
    }
}
RestApi class:-
@RestResource(urlMapping='/Account/*')
public class AcctContactInsert {
    public static void listAcctContactInsert(){
        HttpResponse httpResponse;
        try{
            String endpoint ='';
            Http http = new Http();
            HttpRequest httpRequest = new HttpRequest();
            httpRequest.setMethod('GET');
            httpRequest.setEndpoint(endpoint);
            httpResponse = http.send(httpRequest);
            if(httpResponse.getStatusCode() == 200){
                String strResponse = httpResponse.getBody();
                JSON2Apex jsonApex = JSON2Apex.parse(strResponse);
                for(JSON2Apex.AccountList acctList : jsonApex.accountList){
                    System.debug('AccountList:'+acctList.Name+':'+acctList.ContactItems);  
                }
            }
        }
        catch(Exception ex){
            System.debug('Status Code: ' + httpResponse.getStatusCode());
            System.debug('Status Response: ' + httpResponse.getStatus()); 
        }
    }  
}