org.axonframework.eventhandling.tokenstore.jpa

Class TokenEntry

java.lang.Object

org.axonframework.eventhandling.tokenstore.jpa.TokenEntry

@Entity
 @Entity
public class TokenEntry
extends Object

Implementation of a token entry compatible with JPA that stores its serialized token as a byte array.

Author:

Rene de Waele, Allard Buijze

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TokenEntry.PK Primary key for token entries used by JPA

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	TokenEntry() Default constructor for JPA
	TokenEntry(String processorName, int segment, TrackingToken token, Serializer serializer) Initializes a new token entry for given token, processorName and segment.

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.
String	getProcessorName()
int	getSegment()
SerializedObject<byte[]>	getSerializedToken() Returns the serialized token.
TrackingToken	getToken(Serializer serializer) Returns the token, deserializing it with given serializer
SerializedType	getTokenType() Returns the SerializedType of the serialized token, or null if no token is stored by this entry.
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.
void	updateToken(TrackingToken token, Serializer serializer) Updates a token, using the provided token and serializer to update the serialized token and token type.

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

TokenEntry

public TokenEntry(String processorName,
                  int segment,
                  TrackingToken token,
                  Serializer serializer)

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

Parameters:

token - The tracking token to store

processorName - The name of the processor to store this token for

segment - The segment index of the processor

serializer - The serializer to use when storing a serialized token

TokenEntry

protected TokenEntry()

Default constructor for JPA

Method Detail

getSerializedToken

public SerializedObject<byte[]> 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

public SerializedType getTokenType()

Returns the SerializedType of the serialized token, or null if no token is stored by this entry.

Returns:

the serialized type of the token, or null if no token is stored by this entry

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.

timestampAsString

public String timestampAsString()

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

Returns:

The storage timestamp as string

timestamp

public Instant timestamp()

Returns the storage timestamp of this token entry.

Returns:

The storage timestamp

updateToken

public void updateToken(TrackingToken token,
                        Serializer serializer)

Updates a token, using the provided token and serializer to update the serialized token and token type. It will also update the timestamp to the current time, using the inhirited static Clock.

Parameters:

token - The new token that needs to be persisted

serializer - The serializer that will be used to serialize the token

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

getProcessorName

public String getProcessorName()

getSegment

public int getSegment()