eclipse-vertx/vert.x · error

501 Not Implemented

Error message

501 Not Implemented

What it means

Constant defining the 501 Not Implemented response expectation: applying expecting(SC_NOT_IMPLEMENTED) makes a 501 response fail the request future. The server does not support the functionality required (often an unsupported method); the 'message' is the reason reported on the failure.

Source

Thrown at vertx-core/src/main/java/io/vertx/core/http/HttpResponseExpectation.java:295

  /**
   * 431 Request Header Fields Too Large (RFC6585)
   */
  HttpResponseExpectation SC_REQUEST_HEADER_FIELDS_TOO_LARGE = status(431);

  /**
   * Any 5XX server error
   */
  HttpResponseExpectation SC_SERVER_ERRORS = status(500, 600);

  /**
   * 500 Internal Server Error
   */
  HttpResponseExpectation SC_INTERNAL_SERVER_ERROR = status(500);

  /**
   * 501 Not Implemented
   */
  HttpResponseExpectation SC_NOT_IMPLEMENTED = status(501);

  /**
   * 502 Bad Gateway
   */
  HttpResponseExpectation SC_BAD_GATEWAY = status(502);

  /**
   * 503 Service Unavailable
   */
  HttpResponseExpectation SC_SERVICE_UNAVAILABLE = status(503);

  /**
   * 504 Gateway Timeout
   */
  HttpResponseExpectation SC_GATEWAY_TIMEOUT = status(504);

  /**
   * 505 HTTP Version Not Supported

View on GitHub (pinned to fb308bd8c3)

Solutions

  1. Avoid the unsupported method/feature against this server
  2. Handle the failed future and degrade gracefully
Defensive patterns

Strategy: try-catch

When it happens

Trigger: Thrown at vertx-core/src/main/java/io/vertx/core/http/HttpResponseExpectation.java:295 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of eclipse-vertx/vert.x@fb308bd8c3 (2026-09-06). Data as JSON: /api/errors/03e1575b0ce0f57d. Report an issue: GitHub.