Error codes

Every language throws one error type that carries a code. The message is in English and may change, so always branch on the code.

Language	Error type	Where to read the code
Java	`SejongAuthException`	`getErrorCode()` (`SejongAuthErrorCode`)
Python	`SejongAuthError`	`error.code` (`ErrorCode`)
Node.js	`SejongAuthError`	`error.code` (`ErrorCode`)

Code table

Code	Meaning	Typical cause
`INVALID_INPUT`	Student ID or password is blank	Rejected before any network call. Also a malformed year or month for business periods
`AUTHENTICATION_FAILED`	Wrong student ID or password	Portal verdict `erridpwd`/`Error`. As a fallback, DHC 401 or the SIS logout error
`ACCOUNT_LOCKED`	The portal locked the account after repeated wrong passwords	Portal verdict `pwdNeedChg`
`ACCOUNT_UNAVAILABLE`	The portal account cannot sign in	Use period ended (`invalidDt`) or blocked by the administrator (`invalid`)
`CONNECTION_FAILED`	Cannot reach the portal	Network error, or login retries exhausted
`CONNECTION_TIMEOUT`	Portal timed out	The last login attempt timed out
`SESSION_ERROR`	Portal session handling error	An SSO step answered non-2xx, or an unknown login verdict value
`DATA_FETCH_FAILED`	Failed to fetch student info	A data page answered non-200 or empty
`PARSE_ERROR`	Response structure not as expected	The portal changed a page or JSON structure
`SSL_CONFIGURATION_ERROR`	TLS setup failed	A TLS configuration error while creating the client

Java keeps INVALID_CREDENTIALS, marked @Deprecated. It is never thrown any more and exists only so old code still compiles; Python and Node.js do not have it.

Account lock

The Sejong portal locks an account after repeated wrong passwords.

A lock is released only by resetting the password at the portal password page. Waiting does not release it and the library cannot release it for you.
The library never retries a rejected login: it stops at the first failure without further requests.
If anyone can type a student ID into your service, limit the failure count per student ID. Otherwise someone can repeat failures on purpose with another student’s ID and lock that student’s portal account.

How the verdict is read is in Login verdict and account lock protection.

Handling examples

try {
    SejongAuthResult result = sejongAuthEngine.authenticate(studentId, password);
} catch (SejongAuthException exception) {
    switch (exception.getErrorCode()) {
        case AUTHENTICATION_FAILED -> { /* wrong ID or password: raise the per-ID failure count */ }
        case ACCOUNT_LOCKED -> { /* point to the portal password reset */ }
        case ACCOUNT_UNAVAILABLE -> { /* use period ended or blocked */ }
        case CONNECTION_FAILED, CONNECTION_TIMEOUT -> { /* portal outage: ask to retry later */ }
        default -> { /* parse or session error: log the code only */ }
    }
}

from sejongpeia import authenticate, SejongAuthError, ErrorCode

try:
    result = authenticate(student_id, password)
except SejongAuthError as error:
    if error.code == ErrorCode.AUTHENTICATION_FAILED:
        ...  # wrong ID or password: raise the per-ID failure count
    elif error.code == ErrorCode.ACCOUNT_LOCKED:
        ...  # point to the portal password reset
    elif error.code in (ErrorCode.CONNECTION_FAILED, ErrorCode.CONNECTION_TIMEOUT):
        ...  # portal outage: ask to retry later
    else:
        ...  # parse or session error: log the code only

import { authenticate, SejongAuthError, ErrorCode } from 'pro-sejongpeia';

try {
  const result = await authenticate(studentId, password);
} catch (error) {
  if (!(error instanceof SejongAuthError)) throw error;
  if (error.code === ErrorCode.AUTHENTICATION_FAILED) {
    // wrong ID or password: raise the per-ID failure count
  } else if (error.code === ErrorCode.ACCOUNT_LOCKED) {
    // point to the portal password reset
  } else if (error.code === ErrorCode.CONNECTION_FAILED || error.code === ErrorCode.CONNECTION_TIMEOUT) {
    // portal outage: ask to retry later
  } else {
    // parse or session error: log the code only
  }
}