Status

In the scenario that error happens on the server, a Status object is designed to encapsulate standard http response 4xx and 5xx as well as application specific error code ERRXXXXX (prefixed with ERR with another 5 digits) and error message. Additionally, an description of the error will be available for more info about the error.

Data Elements

Here are the four fields in the Status object.

    int statusCode;
    String code;
    String message;
    String description;

Construct the object from status.json

status.json is a configuration file that contains all the status error defined for the application and it has the structure like this.

{
  "ERR10000": {
    "statusCode": 401,
    "code": "ERR10000",
    "message": "INVALID_AUTH_TOKEN",
    "description": "Incorrect signature or malformed token in authorization header"
  },
  "ERR10001": {
    "statusCode": 401,
    "code": "ERR10001",
    "message": "AUTH_TOKEN_EXPIRED",
    "description": "Jwt token in authorization header expired"
  },
  .
  .
  .
}

To construct the object from this config

    static final String STATUS_METHOD_NOT_ALLOWED = "ERR10008";
    .
    .
    .
    Status status = new Status(STATUS_METHOD_NOT_ALLOWED);

To construct the object with arguments to have a description with context information.

   return new Status("ERR11000", queryParameter.getName(), swaggerOperation.getPathString().original());

Convert to JSON response.

There are several way to serialize the object to JSON in response. And string concat is almost 10 times faster than Jackson ObjectMapper. For one million objects:

Jackson Perf 503
ToString Perf 65

Error code range allocation

The error code prefixed with ERR with another 5 digits so that it can be easily scanned in log files. Also, certain error code can be used to trigger an alert such as email or pager notification on system wide issues.

In order to make sure there is no conflict for error code allocation between teams, here is the rule

10000-19999 reserved for the framework/system.

• 10000-10100 security

• 11000-11999 validation

• 12000-12999 undertow-oauth2

20000-29999 common error codes within your business domain. 90000-99999 customize error code that cannot be found in common range.

Send the JSON as response

    Status status = new Status(STATUS_METHOD_NOT_ALLOWED);
    exchange.setStatusCode(status.getStatusCode());
    exchange.getResponseSender().send(status.toString());