Issue with RestUrl Salesforce

Point Regarding Rest Api Salesforce :


When sending rest request to the resturl , Make sure added the name space in Url.
if Name space not provided will throw the error :
[
    {
        "errorCode": "NOT_FOUND",
        "message": "Could not find a match for URL /Account/0019000001InXHd"
    }
]

So the request Url should be like :when Class is exposed as restresource:
     https://Instance.salesforce.com/services/apexrest/icoder/Account/AccountId
     https://Instance.salesforce.com/services/apexrest/namespace/Account/AccountId