* This exception is typically thrown during authentication or user lookup operations
 * when the specified user does not exist in the system.
 */
public class FessUserNotFoundException extends FessSystemException {

    /** Serial version UID for serialization compatibility */
    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new FessUserNotFoundException with the specified username.
     *

 * This exception is typically used for issues during dictionary file
 * reading, writing, parsing, or other dictionary-related operations.
 */
public class DictionaryException extends FessSystemException {

    /** Serial version UID for serialization. */
    private static final long serialVersionUID = 1L;

    /**
     * Creates a new DictionaryException with the specified message and cause.
     *

 * including configuration errors, authentication token validation failures,
 * communication issues with SSO providers, and other SSO-related problems.
 */
public class SsoLoginException extends FessSystemException {

    /** Serial version UID for serialization compatibility. */
    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new SsoLoginException with the specified detail message.
     *

 * query is malformed, contains invalid syntax, or violates query constraints.
 */
public class InvalidQueryException extends FessSystemException {

    /** Serial version UID for serialization */
    private static final long serialVersionUID = 1L;

    /** Message code for localized error messages */
    private final transient VaMessenger<FessMessages> messageCode;

    /**

Hay algunas diferencias:

* `table=True` le dice a SQLModel que este es un *modelo de tabla*, que debe representar una **tabla** en la base de datos SQL, no es solo un *modelo de datos* (como lo sería cualquier otra clase regular de Pydantic).

* `Field(primary_key=True)` le dice a SQLModel que `id` es la **clave primaria** en la base de datos SQL (puedes aprender más sobre claves primarias de SQL en la documentación de SQLModel).

    * De ce fait, en utilisant FastAPI...

Imaginemos que tienes una *path operation* con un path `/files/{file_path}`.

Pero necesitas que `file_path` en sí mismo contenga un *path*, como `home/johndoe/myfile.txt`.

Entonces, la URL para ese archivo sería algo como: `/files/home/johndoe/myfile.txt`.

### Soporte de OpenAPI

///

## Adicione headers customizados

Há certas situações em que é bastante útil poder adicionar headers customizados no HTTP error. Exemplo disso seria adicionar headers customizados para tipos de segurança.

Você provavelmente não precisará utilizar esses headers diretamente no seu código.

 * such as configuration errors, initialization failures, or critical runtime issues.
 */
public class FessSystemException extends RuntimeException {

    /** Serial version UID for serialization compatibility */
    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new FessSystemException with the specified detail message and cause.
     *

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  // We deliberately avoid caching the asList and hashCode here, to ensure that with