Interface UserProvider

All Known Implementing Classes:
AbstractUserProvider, DelegatingUserProvider, NoOpUserProvider
public interface UserProvider
Service interface for managing User identities in Fluxzero.

A UserProvider is responsible for extracting, resolving, and injecting user identity information into messages. It enables user-aware processing by:

  • Resolving the current authenticated User
  • Looking up users by ID or from message metadata
  • Storing user metadata into messages for downstream correlation

Implementations of this interface can be registered via Java’s ServiceLoader. When multiple implementations are found, they are combined using andThen(UserProvider).

See Also:

  • Field Details

    • defaultUserProvider

      static final UserProvider defaultUserProvider
      Default UserProvider discovered via ServiceLoader. If multiple providers are found, they are chained using andThen(UserProvider). May be null if no provider is registered.

  • Method Details

    • getActiveUser

      default User getActiveUser()
      Returns the currently active user, typically injected by the current context.
      Returns:
      the active User, or User.getCurrent() if not explicitly provided

    • getUserById

      User getUserById(Object userId)
      Retrieves a User by their unique identifier.

      This method is primarily used in TestFixture-based access control tests, such as when using whenCommandByUser(...), to simulate requests by a specific user.

      Implementations may return null if the user cannot be found, or alternatively return a new, unprivileged User instance. The latter approach allows tests to verify authorization behavior for unknown or default users without requiring explicit user creation.

      Parameters:
      userId - the unique identifier of the user (typically a String or number)
      Returns:
      the matching User, a default unprivileged User, or null if not found

    • getSystemUser

      User getSystemUser()
      Returns the User representing the system (non-human) identity. Typically used for scheduled messages, internal services, etc.

    • fromMessage

      User fromMessage(HasMessage message)
      Extracts the User from a given HasMessage instance. Implementations may inspect message metadata or payload to resolve the user identity.
      Parameters:
      message - the message containing potential user-related metadata
      Returns:
      the resolved User, or null if no user info was found

    • containsUser

      boolean containsUser(Metadata metadata)
      Checks if the given metadata contains user information that can be resolved by this provider.
      Parameters:
      metadata - the metadata to inspect
      Returns:
      true if the metadata contains recognizable user information

    • removeFromMetadata

      Metadata removeFromMetadata(Metadata metadata)
      Removes any user-related metadata entries from the given Metadata.
      Parameters:
      metadata - the metadata to clean
      Returns:
      a new Metadata instance without any user-specific keys

    • addToMetadata

      default Metadata addToMetadata(Metadata metadata, User user)
      Adds user-related metadata to a message, overwriting existing values if present.
      Parameters:
      metadata - the original metadata
      user - the user whose info should be added
      Returns:
      new metadata including the user identity

    • addToMetadata

      Metadata addToMetadata(Metadata metadata, User user, boolean ifAbsent)
      Adds user-related metadata to a message.
      Parameters:
      metadata - the original metadata
      user - the user to include
      ifAbsent - if true, metadata is only added if not already present
      Returns:
      updated Metadata with user info conditionally added

    • andThen

      default UserProvider andThen(UserProvider other)
      Combines this provider with another.

      The returned provider will try this provider first, falling back to other if a user cannot be resolved. This is useful for composing multiple resolution strategies.

      Parameters:
      other - another user provider to chain after this one
      Returns:
      a new UserProvider that delegates to both providers