# Exceptions - `HTTPException` and `WebSocketException`

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

        } catch (ComponentLookupException e) {
            Throwable cause = e.getCause();
            while (cause != null && !(cause instanceof LinkageError) && !(cause instanceof ClassNotFoundException)) {
                cause = cause.getCause();
            }

            if ((cause instanceof NoClassDefFoundError) || (cause instanceof ClassNotFoundException)) {

        try:
            data = b64decode(param).decode("ascii")
        except (ValueError, UnicodeDecodeError, binascii.Error):
            raise invalid_user_credentials_exc  # noqa: B904
        username, separator, password = data.partition(":")
        if not separator:
            raise invalid_user_credentials_exc
        return HTTPBasicCredentials(username=username, password=password)


class HTTPBearer(HTTPBase):
    """

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise
        dep -->> handler: Raise HTTPException
        handler -->> client: HTTP error response
        dep -->> dep: Raise other exception
    end

    raw_body = await request.body()
    try:
        data = yaml.safe_load(raw_body)
    except yaml.YAMLError:
        raise HTTPException(status_code=422, detail="Invalid YAML")
    try:
        item = Item.model_validate(data)
    except ValidationError as e:
        raise HTTPException(status_code=422, detail=e.errors(include_url=False))

    try {
      dns.lookup("google.com")
      fail<Any>()
    } catch (ioe: IOException) {
      assertThat(ioe.message).isEqualTo("google.com")
      val cause = ioe.cause!!
      assertThat(cause).isInstanceOf<IOException>()
      assertThat(cause).hasMessage("response size exceeds limit (65536 bytes): 65537 bytes")
    }
  }

  @Test
  fun failOnBadResponse() {
    server.enqueue(dnsResponse("00"))

    }

    /**
     * Creates a new exception with specified cause
     *
     * @param cause
     * @param groupId
     * @param artifactId
     * @param version
     */
    public ModelResolverException(Throwable cause, String groupId, String artifactId, String version) {
        super(cause);
        this.groupId = groupId;
        this.artifactId = artifactId;
        this.version = version;

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise
        dep -->> handler: Raise HTTPException
        handler -->> client: HTTP error response
        dep -->> dep: Raise other exception
    end

}

// Close closer interface to close the underlying closer
func (w *DeadlineWriter) Close() error {
	err := w.WriteCloser.Close()
	w.err = err
	if err == nil {
		w.err = errors.New("we are closed") // Avoids any reuse on the Write() side.
	}
	return err
}

// LimitWriter implements io.WriteCloser.
//
// This is implemented such that we want to restrict
// an enscapsulated writer upto a certain length

        } catch (Exception e) {
            Throwable cause = e.getCause();
            if (cause instanceof ModelBuildingException) {
                String message = "In: " + pom + "\n\n";
                for (ModelProblem problem : ((ModelBuildingException) cause).getProblems()) {
                    message += problem + "\n";
                }