@RestResource(urlMapping='/AccSlaExpireDate/*')
global class AccountSLAExpirationDateUpdate {
    @HttpPost 
    global static List<ResponseWrapper> updateAccSLAExpDate(){
        RestRequest accSlaDateRequest = RestContext.request;
        String jsonResponse = '';
        RestResponse res = RestContext.response;
        
        String requestBody = accSlaDateRequest.requestBody.toString();
        system.debug('requestBodyVal'+requestBody);
        List<accountSLAExpDate> accDateReceived = (List<accountSLAExpDate>) JSON.deserialize(requestBody, List<accountSLAExpDate>.class);
        System.debug('listSizeVal'+accDateReceived.size());
        List<Account> accListToUpdate = new List<Account>();
		
		//////////////// wraper list ///////////////////////
        List<ResponseWrapper> wrperlist = new List<ResponseWrapper>();
		/////////////////////////////////////////////////
        for(accountSLAExpDate accDate : accDateReceived){
            Account acc = new Account();
            acc.Id = Id.valueOf(accDate.ACCOUNT_SOURCE_REF);
            If(accDate.SLAEXPDATE != ''){
                acc.SLAExpirationDate__c = Date.valueOf(accDate.SLAEXPDATE);
            }else{
                acc.SLAExpirationDate__c = NULL;
            } 
            accListToUpdate.add(acc);
        }
        
        Database.SaveResult[] srList = database.update(accListToUpdate,false);
        
        for (Database.SaveResult sr : srList){
            if (sr.isSuccess()){
				
			    
                jsonResponse = '{"response": {"status": "Successfully updated"}}';
                res.responseBody = blob.valueOf(jsonResponse);
				wrperlist.add(new ResponseWrapper(res.responseBody.Id,status)); /// you need to parse and check it
				
                //return;
            }else {
			   res.responseBody = Blob.valueOf(err.getMessage());
			   wrperlist.add(new ResponseWrapper(res.responseBody.Id,res.statusCode)); /// you need to parse and check it
               //res.statusCode = 500;
			   //return;
                // Operation failed, so get all errors                
                /*for(Database.Error err : sr.getErrors()) {
                    System.debug('The following error has occurred.'+sr.getId());                    
                    System.debug(err.getStatusCode() + ': ' + err.getMessage());
                    System.debug('Account fields that affected this error: ' + err.getFields());
                }*/
            }
        }
		
		return wrperlist;
    }
    global class accountSLAExpDate{
        public String ACCOUNT_SOURCE_REF;  //Account Id
        public String SLAEXPDATE;  //yyyy-mm-dd format
    }
}


///////////////////////////////////////////  wrapper class ///////////////////////////////////

public class ResponseWrapper{
    public String Id ;
    public string errorStatus;
    public integer errorCode;
       public ResponseWrapper(String Id, String statusCode){
        this.Id  = Id;
        this.errorStatus = statusCode;
    }

}