org.axonframework.eventhandling.tokenstore

Class AbstractTokenEntry<T>

java.lang.Object

org.axonframework.eventhandling.tokenstore.AbstractTokenEntry<T>

Type Parameters:

T - The serialized data type of the token

Direct Known Subclasses:

GenericTokenEntry, TokenEntry

@MappedSuperclass
public abstract class AbstractTokenEntry<T>
extends Object

Abstract base class of a JPA entry containing a serialized tracking token belonging to a given process.

Author:

Rene de Waele

Field Summary

Fields

Modifier and Type	Field and Description
static Clock	clock The clock used to persist timestamps in this entry.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractTokenEntry() Default constructor required for JPA
protected	AbstractTokenEntry(TrackingToken token, Serializer serializer, Class<T> contentType) Initializes a new token entry for given token, process and segment.
protected	AbstractTokenEntry(T token, String tokenType, String timestamp, String owner) Initializes a token entry from existing data.

Method Summary

Modifier and Type	Method and Description
boolean	claim(String owner, TemporalAmount claimTimeout) Attempt to claim ownership of this token.
String	getOwner() Returns the identifier of the process (JVM) having a claim on this token, or null if the token isn't claimed.
abstract String	getProcessorName() Returns the name of the process to which this token belongs.
abstract int	getSegment() Returns the segment index of the process to which this token belongs.
SerializedObject<T>	getSerializedToken() Returns the serialized token.
TrackingToken	getToken(Serializer serializer) Returns the token, deserializing it with given serializer
protected SerializedType	getTokenType() Returns the SerializedType of the serialized token.
boolean	mayClaim(String owner, TemporalAmount claimTimeout) Check if given owner may claim this token.
boolean	releaseClaim(String owner) Release any claim of ownership currently active on this Token, if owned by the given owner.
Instant	timestamp() Returns the storage timestamp of this token entry.
String	timestampAsString() Returns the storage timestamp of this token entry as a String.
abstract void	updateToken(TrackingToken token, Serializer serializer) Update this entry with the given token, serializing it using given serializer.
protected void	updateToken(TrackingToken token, Serializer serializer, Class<T> contentType) Update the token data to the given token, using given serializer to serialize it to the given contentType.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

clock

public static Clock clock

The clock used to persist timestamps in this entry. Defaults to UTC system time.

Constructor Detail

AbstractTokenEntry

protected AbstractTokenEntry(TrackingToken token,
                             Serializer serializer,
                             Class<T> contentType)

Initializes a new token entry for given token, process and segment. The given serializer can be used to serialize the token before it is stored.

Parameters:

token - The tracking token to store

serializer - The serializer to use when storing a serialized token

contentType - The content type after serialization

AbstractTokenEntry

protected AbstractTokenEntry(T token,
                             String tokenType,
                             String timestamp,
                             String owner)

Initializes a token entry from existing data.

Parameters:

token - the serialized token

tokenType - the serialized type of the token

timestamp - the timestamp of the token

owner - the owner of the token

AbstractTokenEntry

protected AbstractTokenEntry()

Default constructor required for JPA

Method Detail

getSerializedToken

public SerializedObject<T> getSerializedToken()

Returns the serialized token.

Returns:

the serialized token stored in this entry

getToken

public TrackingToken getToken(Serializer serializer)

Returns the token, deserializing it with given serializer

Parameters:

serializer - The serialize to deserialize the token with

Returns:

the deserialized token stored in this entry

getTokenType

protected SerializedType getTokenType()

Returns the SerializedType of the serialized token.

Returns:

the serialized type of the token

timestamp

public Instant timestamp()

Returns the storage timestamp of this token entry.

Returns:

The storage timestamp

timestampAsString

public String timestampAsString()

Returns the storage timestamp of this token entry as a String.

Returns:

The storage timestamp as string

updateToken

public abstract void updateToken(TrackingToken token,
                                 Serializer serializer)

Update this entry with the given token, serializing it using given serializer.

Parameters:

token - The token to update the entry with

serializer - The serializer to serialize data with

getProcessorName

public abstract String getProcessorName()

Returns the name of the process to which this token belongs.

Returns:

the process name

getSegment

public abstract int getSegment()

Returns the segment index of the process to which this token belongs.

Returns:

the segment index

claim

public boolean claim(String owner,
                     TemporalAmount claimTimeout)

Attempt to claim ownership of this token. When successful, this method returns true, otherwise false. When a claim fails, this token should not be used, as it is already being used in another process.

If a claim exists, but it is older than given claimTimeout, the claim may be 'stolen'.

Parameters:

owner - The name of the current node, to register as owner. This name must be unique for multiple instances of the same logical processor

claimTimeout - The time after which a claim may be 'stolen' from its current owner

Returns:

true if the claim succeeded, otherwise false

mayClaim

public boolean mayClaim(String owner,
                        TemporalAmount claimTimeout)

Check if given owner may claim this token.

Parameters:

owner - The name of the current node, to register as owner. This name must be unique for multiple instances of the same logical processor

claimTimeout - The time after which a claim may be 'stolen' from its current owner

Returns:

true if the claim may be made, false otherwise

releaseClaim

public boolean releaseClaim(String owner)

Release any claim of ownership currently active on this Token, if owned by the given owner.

Parameters:

owner - The name of the current node, which was registered as the owner

Returns:

true of the claim was successfully released, or false if the token has been claimed by another owner.

getOwner

public String getOwner()

Returns the identifier of the process (JVM) having a claim on this token, or null if the token isn't claimed.

Returns:

the process (JVM) that claimed this token

updateToken

protected final void updateToken(TrackingToken token,
                                 Serializer serializer,
                                 Class<T> contentType)

Update the token data to the given token, using given serializer to serialize it to the given contentType.

Parameters:

token - The token representing the state to update to

serializer - The serializer to update token to

contentType - The type of data to represent the serialized data in