DefaultErrorMapper

Default mapping.

A cancellation - mapped while the current thread is interrupted, or caused by an InterruptedException or ClosedByInterruptException (see CancelledError.isCancellation) - becomes a CancelledError. Mapping classifies only and never sets the interrupt flag: it may run on a thread other than the interrupted one, such as a Future callback's pool thread.

An exception whose message names HTTP status 401 becomes an AuthenticationError (code 401, carrying the redacted message), and one naming 429 a RateLimitError; 401 wins when a message names both. A message names a status only in an HTTP context, at a word boundary: after HTTP, status, status code, http status, error code or response code, optionally quoted as a JSON key (HTTP 401, Status Code: 429, "status": 401, http_status=429), before its reason phrase (401 Unauthorized, 429 Too Many Requests), or leading the message as openai-java and anthropic-java write it (401: <body>, also behind up to eight wrapping exceptions' ClassName:). A message that merely contains the digits - an index, an id, a port or a count - is an UnknownError carrying the exception as its cause, as is anything else not matched above.

Known false positive: that last, SDK shape carries no other HTTP marker, so any message that starts with 401: or 429: (optionally behind SomeException: prefixes) is classified, even when the number means something else, such as a line number in 429: unexpected token.

Only the first 4 KiB and the last 1 KiB of a message are scanned (see ScanHead), and every pattern runs in linear time, so mapping an exception that carries a large response body is cheap.

The message of every error built here is redacted and capped (Redaction.safeBody), since an exception's message often echoes a provider's response body and with it a request header or a key. The cause is not: an UnknownError keeps the original exception, whose own getMessage and stack trace are unredacted. A logger or handler that prints the cause (logger.error(msg, err.cause), printStackTrace) writes that text in the clear.