@RestResource(urlMapping='/*')
global with sharing class RestResource {
    @HttpGet
    webservice static void showContact() {
        Boolean isValid;
        String phone;
        List<Contact> resultCon= new List<Contact>();
        RestRequest request = RestContext.request;
        RestResponse response = RestContext.response;

        try {
            phone = (request.requestURI.substring(request.requestURI.lastIndexOf('/')+1)).replaceAll('[^0-9]','');
            isValid = Regex_Validator.isValidPhone(phone);
            resultCon = [SELECT id, phone , lastname FROM Contact WHERE phone = :phone];
            response.addHeader('Content-Type', 'application/json');
            response.responseBody = Blob.valueOf(JSON.serialize(resultCon[0].id));
        } catch(exception e) {
            response.addHeader('Content-Type', 'text/plain');
            if(resultCon.IsEmpty()) {
                response.responseBody = Blob.valueOf('Sorry no match');
            }
            if(!isValid) {
                response.responseBody = Blob.valueOf('Check format phonenumber :+00 0000000000');
            }else{
               response.responseBody = Blob.valueOf('exception '+e);
            }
        }
    }
}