org.axonframework.eventhandling

Interface WrappedToken

All Superinterfaces:

TrackingToken

All Known Implementing Classes:

MergedTrackingToken, ReplayToken

public interface WrappedToken
extends TrackingToken

Interface marking a token that wraps another token. As certain implementations may depend on specific token types, Tokens that wrap another must provide a means to retrieve the original token.

Since:

3.2

Author:

Allard Buijze

Method Summary

Modifier and Type	Method and Description
static TrackingToken	advance(TrackingToken base, TrackingToken target) Advance the given base TrackingToken to the target.
TrackingToken	advancedTo(TrackingToken newToken) Advance this token to the given newToken.
TrackingToken	lowerBound() Returns the token representing the current position in the stream.
<R extends TrackingToken> Optional<R>	unwrap(Class<R> tokenType) Retrieve a token of given tokenType if it is wrapped by this token.
static <R extends TrackingToken> Optional<R>	unwrap(TrackingToken token, Class<R> tokenType) Unwrap the given token until a token of given tokenType is exposed.
static TrackingToken	unwrapLowerBound(TrackingToken token) Extracts a raw token describing the current processing position of the given token.
static TrackingToken	unwrapUpperBound(TrackingToken token) Extracts a raw token describing the current processing position of the given token.
TrackingToken	upperBound() Returns the token representing the furthest position in the stream described by this token.

Methods inherited from interface org.axonframework.eventhandling.TrackingToken

covers, lowerBound, position, upperBound

Method Detail

unwrapLowerBound

static TrackingToken unwrapLowerBound(TrackingToken token)

Extracts a raw token describing the current processing position of the given token. If the given token is a wrapped token, it will be unwrapped until the raw token (as received from the event stream) is reached.

The returned token represents the minimal position described by the given token (which may express a range)

Parameters:

token - The token to unwrap

Returns:

the raw lower bound token described by given token

unwrapUpperBound

static TrackingToken unwrapUpperBound(TrackingToken token)

Extracts a raw token describing the current processing position of the given token. If the given token is a wrapped token, it will be unwrapped until the raw token (as received from the event stream) is reached.

The returned token represents the furthest position described by the given token (which may express a range)

Parameters:

token - The token to unwrap

Returns:

the raw upper bound token described by given token

unwrap

static <R extends TrackingToken> Optional<R> unwrap(TrackingToken token,
                                                    Class<R> tokenType)

Unwrap the given token until a token of given tokenType is exposed. Returns an empty optional if the given token is not a WrappedToken instance, or if it does not wrap a token of expected tokenType.

Type Parameters:

R - The generic type of the token to reveal

Parameters:

token - The token to unwrap

tokenType - The type of token to reveal

Returns:

an optional with the unwrapped token, if found

advance

static TrackingToken advance(TrackingToken base,
                             TrackingToken target)

Advance the given base TrackingToken to the target. This method will return the target as is if the base is not an implementation of a WrappedToken. If it is a WrappedToken, it will invoke advancedTo(TrackingToken) on the base, using the target.

Parameters:

base - the TrackingToken to validate if it's a WrappedToken which can be advancedTo(TrackingToken)

target - the TrackingToken to advance the given base to

Returns:

the target if base does not implement WrappedToken, otherwise the result of invoking advancedTo(TrackingToken) on the base using the target

advancedTo

TrackingToken advancedTo(TrackingToken newToken)

Advance this token to the given newToken.

Parameters:

newToken - The token representing the position to advance to

Returns:

a token representing the new position

lowerBound

TrackingToken lowerBound()

Returns the token representing the current position in the stream.

Returns:

the token representing the current position in the stream

upperBound

TrackingToken upperBound()

Returns the token representing the furthest position in the stream described by this token. This is usually a position that has been (partially) processed before.

Returns:

the token representing the furthest position reached in the stream

unwrap

<R extends TrackingToken> Optional<R> unwrap(Class<R> tokenType)

Retrieve a token of given tokenType if it is wrapped by this token.

Type Parameters:

R - The generic type of the token to unwrap to

Parameters:

tokenType - The type of token to unwrap to

Returns:

an optional with the unwrapped token, if found