Package org.axonframework.eventsourcing.eventstore.jdbc

Class JdbcEventStorageEngine

java.lang.Object

org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine

org.axonframework.eventsourcing.eventstore.BatchingEventStorageEngine

org.axonframework.eventsourcing.eventstore.jdbc.JdbcEventStorageEngine

All Implemented Interfaces:

EventStorageEngine

public class JdbcEventStorageEngine
extends BatchingEventStorageEngine

An EventStorageEngine implementation that uses JDBC to store and fetch events.

By default, it stores the payload of events as a serialized blob of bytes. It uses other columns to store meta-data that allows quick finding of DomainEvents for a specific aggregate in the correct order.

Before using this store make sure the database contains a table named EventSchema.domainEventTable() and EventSchema.snapshotTable() in which to store events and snapshots in respectively. For convenience, these tables can be constructed through the createSchema(EventTableFactory) operation.

Since:

3.0

Author:

Rene de Waele

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	JdbcEventStorageEngine.Builder	Builder class to instantiate a JdbcEventStorageEngine.

Field Summary

Fields inherited from class org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine

upcasterChain

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	JdbcEventStorageEngine(JdbcEventStorageEngine.Builder builder)	Instantiate a JdbcEventStorageEngine based on the fields contained in the JdbcEventStorageEngine.Builder.

Method Summary

Modifier and Type	Method	Description
protected PreparedStatement	appendEvents(Connection connection, List<? extends EventMessage<?>> events, Serializer serializer)	Creates a statement to be used at appendEvents(List, Serializer).
protected void	appendEvents(List<? extends EventMessage<?>> events, Serializer serializer)	Append given events to the backing database.
protected PreparedStatement	appendSnapshot(Connection connection, DomainEventMessage<?> snapshot, Serializer serializer)	Creates a statement to be used at AbstractEventStorageEngine.storeSnapshot(DomainEventMessage).
static JdbcEventStorageEngine.Builder	builder()	Instantiate a Builder to be able to create a JdbcEventStorageEngine.
protected PreparedStatement	cleanGaps(Connection connection, SortedSet<Long> gaps)	Creates a statement to be used at cleanGaps(TrackingToken).
TrackingToken	createHeadToken()	Creates a token that is at the head of an event stream - that tracks all new events.
protected PreparedStatement	createHeadToken(Connection connection)	Creates a statement to be used at createHeadToken().
void	createSchema(EventTableFactory schemaFactory)	Performs the DDL queries to create the schema necessary for this storage engine implementation.
TrackingToken	createTailToken()	Creates a token that is at the tail of an event stream - that tracks events from the beginning of time.
protected PreparedStatement	createTailToken(Connection connection)	Creates a statement to be used at createTailToken().
protected PreparedStatement	createTokenAt(Connection connection, Instant dateTime)	Creates a statement to be used at createTokenAt(Instant).
TrackingToken	createTokenAt(Instant dateTime)	Creates a token that tracks all events after given dateTime.
protected PreparedStatement	deleteSnapshots(Connection connection, String aggregateIdentifier, long sequenceNumber)	Creates a statement to be used at AbstractEventStorageEngine.storeSnapshot(DomainEventMessage).
protected String	domainEventFields()	Deprecated. in favor of EventSchema.domainEventFields()
protected List<? extends DomainEventData<?>>	fetchDomainEvents(String aggregateIdentifier, long firstSequenceNumber, int batchSize)	Returns a batch of events published by an aggregate with given aggregateIdentifier.
protected boolean	fetchForAggregateUntilEmpty()	Specifies whether the BatchingEventStorageEngine.readEventData(String, long) should proceed fetching events for an aggregate until an empty batch is returned.
protected PreparedStatement	fetchTrackedEvents(Connection connection, long index)	Creates a statement to be used at fetchTrackedEvents(TrackingToken, int).
protected List<? extends TrackedEventData<?>>	fetchTrackedEvents(TrackingToken lastToken, int batchSize)	Returns a batch of serialized event data entries in the event storage that have a TrackingToken greater than the given lastToken.
protected Connection	getConnection()	Returns a Connection to the database.
protected DomainEventData<?>	getDomainEventData(ResultSet resultSet)	Extracts the next domain event entry from the given resultSet.
protected DomainEventData<?>	getSnapshotData(ResultSet resultSet)	Extracts the next snapshot entry from the given resultSet.
protected TrackedEventData<?>	getTrackedEventData(ResultSet resultSet, GapAwareTrackingToken previousToken)	Extracts the next tracked event entry from the given resultSet.
Optional<Long>	lastSequenceNumberFor(String aggregateIdentifier)	Returns the last known sequence number for the given aggregateIdentifier.
protected PreparedStatement	lastSequenceNumberFor(Connection connection, String aggregateIdentifier)	Creates a statement to be used at lastSequenceNumberFor(String).
protected PreparedStatement	readEventData(Connection connection, String identifier, long firstSequenceNumber, int batchSize)	Creates a statement to be used at fetchDomainEvents(String, long, int)
protected PreparedStatement	readEventData(Connection connection, TrackingToken lastToken, int batchSize)	Creates a statement to read tracked event entries stored since given tracking token.
protected PreparedStatement	readEventDataWithGaps(Connection connection, long globalIndex, int batchSize, List<Long> gaps)	Creates a statement to be used at fetchTrackedEvents(TrackingToken, int)
protected PreparedStatement	readEventDataWithoutGaps(Connection connection, long globalIndex, int batchSize)	Creates a statement to be used at fetchTrackedEvents(TrackingToken, int)
protected <T> T	readPayload(ResultSet resultSet, String columnName)	Reads a serialized object from the given resultSet at given columnIndex.
protected Stream<? extends DomainEventData<?>>	readSnapshotData(String aggregateIdentifier)	Returns a stream of serialized event entries for given aggregateIdentifier if the backing database contains a snapshot of the aggregate.
protected PreparedStatement	readSnapshotData(Connection connection, String identifier)	Creates a statement to be used at readSnapshotData(String).
protected Object	readTimeStamp(ResultSet resultSet, String columnName)	Reads a timestamp from the given resultSet at given columnIndex.
protected EventSchema	schema()	Returns the EventSchema that defines the table and column names of event tables in the database.
void	setGapCleaningThreshold(int gapCleaningThreshold)	Deprecated. Use the gapCleaningThreshold(int) in the builder() instead
void	setGapTimeout(int gapTimeout)	Deprecated. Use the gapTimeout(int) in the builder() instead
protected void	storeSnapshot(DomainEventMessage<?> snapshot, Serializer serializer)	Store the given snapshot of an Aggregate.
protected String	trackedEventFields()	Deprecated. in favor of EventSchema.trackedEventFields()
protected void	writeTimestamp(PreparedStatement preparedStatement, int position, Instant timestamp)	Write a timestamp from a Instant to a data value suitable for the database scheme.

Methods inherited from class org.axonframework.eventsourcing.eventstore.BatchingEventStorageEngine

batchSize, readEventData, readEventData

Methods inherited from class org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine

appendEvents, getEventSerializer, getSnapshotSerializer, handlePersistenceException, readEvents, readEvents, readSnapshot, storeSnapshot

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.eventsourcing.eventstore.EventStorageEngine

appendEvents, readEvents

Constructor Details

JdbcEventStorageEngine

protected JdbcEventStorageEngine(JdbcEventStorageEngine.Builder builder)

Instantiate a JdbcEventStorageEngine based on the fields contained in the JdbcEventStorageEngine.Builder.

Will assert that the event and snapshot Serializer, the ConnectionProvider and TransactionManager are not null, and will throw an AxonConfigurationException if any of them is null.

Parameters:

builder - the JdbcEventStorageEngine.Builder used to instantiate a JdbcEventStorageEngine instance

Method Details

builder

public static JdbcEventStorageEngine.Builder builder()

Instantiate a Builder to be able to create a JdbcEventStorageEngine.

The following configurable fields have defaults:

• The EventUpcaster defaults to an NoOpEventUpcaster.
• The PersistenceExceptionResolver is defaulted to a JdbcSQLErrorCodesResolver
• The snapshotFilter defaults to a SnapshotFilter.allowAll() instance.
• The batchSize defaults to an integer of size 100.
• The dataType is defaulted to the byte[] type.
• The EventSchema defaults to an EventSchema() call.
• The maxGapOffset defaults to an integer of size 10000.
• The lowestGlobalSequence defaults to a long of size 1.
• The gapTimeout defaults to an integer of size 60000 (1 minute).
• The gapCleaningThreshold defaults to an integer of size 250.
• The extendedGapCheckEnabled defaults to true.
• The createTokenAt defaults to JdbcEventStorageEngineStatements.createTokenAt(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.time.Instant).
• The appendEvents defaults to JdbcEventStorageEngineStatements.appendEvents(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.Class<?>, java.util.List<? extends org.axonframework.eventhandling.EventMessage<?>>, org.axonframework.serialization.Serializer, org.axonframework.eventsourcing.eventstore.jdbc.statements.TimestampWriter).
• The lastSequenceNumberFor defaults to JdbcEventStorageEngineStatements.lastSequenceNumberFor(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String).
• The createTailToken defaults to JdbcEventStorageEngineStatements.createTailToken(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema).
• The createHeadToken defaults to JdbcEventStorageEngineStatements.createHeadToken(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema).
• The appendSnapshot defaults to JdbcEventStorageEngineStatements.appendSnapshot(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.Class<?>, org.axonframework.eventhandling.DomainEventMessage<?>, org.axonframework.serialization.Serializer, org.axonframework.eventsourcing.eventstore.jdbc.statements.TimestampWriter).
• The deleteSnapshots defaults to JdbcEventStorageEngineStatements.deleteSnapshots(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String, long).
• The fetchTrackedEvents defaults to JdbcEventStorageEngineStatements.fetchTrackedEvents(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, long).
• The cleanGaps defaults to JdbcEventStorageEngineStatements.cleanGaps(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.util.SortedSet<java.lang.Long>).
• The readEventDataForAggregate defaults to JdbcEventStorageEngineStatements.readEventDataForAggregate(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String, long, int).
• The readSnapshotData defaults to JdbcEventStorageEngineStatements.readSnapshotData(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String).
• The readEventDataWithoutGaps defaults to JdbcEventStorageEngineStatements.readEventDataWithoutGaps(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, long, int).
• The readEventDataWithGaps defaults to JdbcEventStorageEngineStatements.readEventDataWithGaps(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, long, int, java.util.List<java.lang.Long>).

The event and snapshot Serializer, ConnectionProvider and TransactionManager are hard requirements and as such should be provided.

Returns:

a Builder to be able to create a JdbcEventStorageEngine

createTokenAt

protected PreparedStatement createTokenAt(Connection connection,
 Instant dateTime)
                                   throws SQLException

Creates a statement to be used at createTokenAt(Instant).

Parameters:

connection - The connection to the database.

dateTime - The dateTime where the token will be created.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

appendEvents

protected PreparedStatement appendEvents(Connection connection,
 List<? extends EventMessage<?>> events,
 Serializer serializer)
                                  throws SQLException

Creates a statement to be used at appendEvents(List, Serializer).

Parameters:

connection - The connection to the database.

events - The events to be added.

serializer - The serializer for the payload and metadata.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

lastSequenceNumberFor

protected PreparedStatement lastSequenceNumberFor(Connection connection,
 String aggregateIdentifier)
                                           throws SQLException

Creates a statement to be used at lastSequenceNumberFor(String).

Parameters:

connection - The connection to the database.

aggregateIdentifier - The identifier of the aggregate.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

createTailToken

protected PreparedStatement createTailToken(Connection connection)
                                     throws SQLException

Creates a statement to be used at createTailToken().

Parameters:

connection - The connection to the database.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

createHeadToken

protected PreparedStatement createHeadToken(Connection connection)
                                     throws SQLException

Creates a statement to be used at createHeadToken().

Parameters:

connection - The connection to the database.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

appendSnapshot

protected PreparedStatement appendSnapshot(Connection connection,
 DomainEventMessage<?> snapshot,
 Serializer serializer)
                                    throws SQLException

Creates a statement to be used at AbstractEventStorageEngine.storeSnapshot(DomainEventMessage).

Parameters:

connection - The connection to the database.

snapshot - The snapshot to be appended.

serializer - The serializer for the payload and metadata.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

deleteSnapshots

protected PreparedStatement deleteSnapshots(Connection connection,
 String aggregateIdentifier,
 long sequenceNumber)
                                     throws SQLException

Creates a statement to be used at AbstractEventStorageEngine.storeSnapshot(DomainEventMessage).

Parameters:

connection - The connection to the database.

aggregateIdentifier - The identifier of the aggregate taken from the snapshot.

sequenceNumber - The sequence number taken from the snapshot.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

fetchTrackedEvents

protected PreparedStatement fetchTrackedEvents(Connection connection,
 long index)
                                        throws SQLException

Creates a statement to be used at fetchTrackedEvents(TrackingToken, int).

Parameters:

connection - The connection to the database.

index - The index taken from the tracking token.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

cleanGaps

protected PreparedStatement cleanGaps(Connection connection,
 SortedSet<Long> gaps)
                               throws SQLException

Creates a statement to be used at cleanGaps(TrackingToken).

Parameters:

connection - The connection to the database.

gaps - The Set of gaps taken from the tracking token.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

readEventData

protected PreparedStatement readEventData(Connection connection,
 String identifier,
 long firstSequenceNumber,
 int batchSize)
                                   throws SQLException

Creates a statement to be used at fetchDomainEvents(String, long, int)

Parameters:

connection - The connection to the database.

identifier - The identifier of the aggregate.

firstSequenceNumber - The expected sequence number of the first returned entry.

batchSize - The number of items to include in the batch.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

readSnapshotData

protected PreparedStatement readSnapshotData(Connection connection,
 String identifier)
                                      throws SQLException

Creates a statement to be used at readSnapshotData(String).

Parameters:

connection - The connection to the database.

identifier - The identifier of the aggregate.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

readEventDataWithoutGaps

protected PreparedStatement readEventDataWithoutGaps(Connection connection,
 long globalIndex,
 int batchSize)
                                              throws SQLException

Creates a statement to be used at fetchTrackedEvents(TrackingToken, int)

Parameters:

connection - The connection to the database.

globalIndex - The index taken from the tracking token.

batchSize - The number of items to include in the batch

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

readEventDataWithGaps

protected PreparedStatement readEventDataWithGaps(Connection connection,
 long globalIndex,
 int batchSize,
 List<Long> gaps)
                                           throws SQLException

Creates a statement to be used at fetchTrackedEvents(TrackingToken, int)

Parameters:

connection - The connection to the database.

globalIndex - The index taken from the tracking token.

batchSize - The number of items to include in the batch

gaps - The Set of gaps taken from the tracking token.

Returns:

The newly created PreparedStatement.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

createSchema

public void createSchema(EventTableFactory schemaFactory)

Performs the DDL queries to create the schema necessary for this storage engine implementation.

Parameters:

schemaFactory - Factory of the event schema.

Throws:

EventStoreException - when an error occurs executing SQL statements.

appendEvents

protected void appendEvents(List<? extends EventMessage<?>> events,
 Serializer serializer)

Description copied from class: AbstractEventStorageEngine

Append given events to the backing database. Use the given serializer to serialize the event's payload and metadata.

Specified by:

appendEvents in class AbstractEventStorageEngine

Parameters:

events - Events to append to the database

serializer - Serializer used to convert the events to a suitable format for storage

storeSnapshot

protected void storeSnapshot(DomainEventMessage<?> snapshot,
 Serializer serializer)

Description copied from class: AbstractEventStorageEngine

Store the given snapshot of an Aggregate. Implementations may override any existing snapshot of the Aggregate with the given snapshot.

Specified by:

storeSnapshot in class AbstractEventStorageEngine

Parameters:

snapshot - Snapshot Event of the aggregate

serializer - Serializer used to convert the snapshot event to a suitable format for storage

lastSequenceNumberFor

public Optional<Long> lastSequenceNumberFor(@Nonnull
 String aggregateIdentifier)

Description copied from interface: EventStorageEngine

Returns the last known sequence number for the given aggregateIdentifier.

While it's recommended to use the sequence numbers from the DomainEventStream, there are cases where knowing the sequence number is required, without having read the actual events. In such case, this method is a viable alternative.

Parameters:

aggregateIdentifier - The identifier to find the last sequence number for

Returns:

an optional with the highest sequence number, or an empty optional if the aggregate identifier wasn't found

createTailToken

public TrackingToken createTailToken()

Description copied from interface: EventStorageEngine

Creates a token that is at the tail of an event stream - that tracks events from the beginning of time.

Returns:

a tracking token at the tail of an event stream, if event stream is empty null is returned

createHeadToken

public TrackingToken createHeadToken()

Description copied from interface: EventStorageEngine

Creates a token that is at the head of an event stream - that tracks all new events.

Returns:

a tracking token at the head of an event stream, if event stream is empty null is returned

createTokenAt

public TrackingToken createTokenAt(@Nonnull
 Instant dateTime)

Description copied from interface: EventStorageEngine

Creates a token that tracks all events after given dateTime. If there is an event exactly at the given dateTime, it will be tracked too.

Parameters:

dateTime - The date and time for determining criteria how the tracking token should be created. A tracking token should point to very first event before this date and time.

Returns:

a tracking token at the given dateTime, if there aren't events matching this criteria null is returned

fetchDomainEvents

protected List<? extends DomainEventData<?>> fetchDomainEvents(String aggregateIdentifier,
 long firstSequenceNumber,
 int batchSize)

Description copied from class: BatchingEventStorageEngine

Returns a batch of events published by an aggregate with given aggregateIdentifier.

The sequence numbers in the returned batch should be ordered by sequence number. The first event in the batch should have a sequence number equal to or larger than given firstSequenceNumber. Implementations should make sure the returned batch does not contain gaps between events due to uncommitted storage transactions.

If the returned number of entries is smaller than the given batchSize it is assumed that the storage holds no further applicable entries. Implementations for which this is not always the case should override BatchingEventStorageEngine.fetchForAggregateUntilEmpty() to return true and preferably configure a better BatchingEventStorageEngine.Builder.finalAggregateBatchPredicate(Predicate) to provide a better heuristic for detecting the last batch in a stream.

Specified by:

fetchDomainEvents in class BatchingEventStorageEngine

Parameters:

aggregateIdentifier - The identifier of the aggregate to open a stream for

firstSequenceNumber - The sequence number of the first excepted event entry

batchSize - The maximum number of events that should be returned

Returns:

a batch of serialized event entries for the given aggregate

fetchForAggregateUntilEmpty

protected boolean fetchForAggregateUntilEmpty()

Description copied from class: BatchingEventStorageEngine

Specifies whether the BatchingEventStorageEngine.readEventData(String, long) should proceed fetching events for an aggregate until an empty batch is returned. Defaults to false, as Aggregate event batches typically do not have gaps in them.

Overrides:

fetchForAggregateUntilEmpty in class BatchingEventStorageEngine

Returns:

a boolean specifying whether BatchingEventStorageEngine.readEventData(String, long) should proceed fetching events for an aggregate until an empty batch is returned

fetchTrackedEvents

protected List<? extends TrackedEventData<?>> fetchTrackedEvents(TrackingToken lastToken,
 int batchSize)

Description copied from class: BatchingEventStorageEngine

Returns a batch of serialized event data entries in the event storage that have a TrackingToken greater than the given lastToken. Event entries in the stream should be ordered by tracking token. If the lastToken is null a stream containing all events should be returned.

Only if the returned List is empty the event storage assumes that the backing database holds no further applicable entries.

Specified by:

fetchTrackedEvents in class BatchingEventStorageEngine

Parameters:

lastToken - Object describing the global index of the last processed event or null to create a stream of all events in the store

batchSize - The maximum number of events that should be returned

Returns:

A batch of tracked event messages stored since the given tracking token

readSnapshotData

protected Stream<? extends DomainEventData<?>> readSnapshotData(String aggregateIdentifier)

Description copied from class: AbstractEventStorageEngine

Returns a stream of serialized event entries for given aggregateIdentifier if the backing database contains a snapshot of the aggregate.

It is required that specific event storage engines return snapshots in descending order of their sequence number.

Specified by:

readSnapshotData in class AbstractEventStorageEngine

Parameters:

aggregateIdentifier - The aggregate identifier to fetch a snapshot for

Returns:

A stream of serialized snapshots of the aggregate

readEventData

protected PreparedStatement readEventData(Connection connection,
 TrackingToken lastToken,
 int batchSize)
                                   throws SQLException

Creates a statement to read tracked event entries stored since given tracking token. Pass a trackingToken of null to create a statement for all entries in the storage.

Parameters:

connection - The connection to the database.

lastToken - Object describing the global index of the last processed event or null to return all entries in the store.

batchSize - The number of items to include in the batch

Returns:

A PreparedStatement that returns event entries for the given query when executed.

Throws:

SQLException - when an exception occurs while creating the prepared statement.

getTrackedEventData

protected TrackedEventData<?> getTrackedEventData(ResultSet resultSet,
 GapAwareTrackingToken previousToken)
                                           throws SQLException

Extracts the next tracked event entry from the given resultSet.

Parameters:

resultSet - The results of a query for tracked events.

previousToken - The last known token of the tracker before obtaining this result set.

Returns:

The next tracked event.

Throws:

SQLException - when an exception occurs while creating the event data.

getDomainEventData

protected DomainEventData<?> getDomainEventData(ResultSet resultSet)
                                         throws SQLException

Extracts the next domain event entry from the given resultSet.

Parameters:

resultSet - The results of a query for domain events of an aggregate.

Returns:

The next domain event.

Throws:

SQLException - when an exception occurs while creating the event data.

getSnapshotData

protected DomainEventData<?> getSnapshotData(ResultSet resultSet)
                                      throws SQLException

Extracts the next snapshot entry from the given resultSet.

Parameters:

resultSet - The results of a query for a snapshot of an aggregate.

Returns:

The next snapshot data.

Throws:

SQLException - when an exception occurs while creating the event data.

readTimeStamp

protected Object readTimeStamp(ResultSet resultSet,
 String columnName)
                        throws SQLException

Reads a timestamp from the given resultSet at given columnIndex. The resultSet is positioned in the row that contains the data. This method must not change the row in the result set.

Parameters:

resultSet - The resultSet containing the stored data.

columnName - The name of the column containing the timestamp.

Returns:

an object describing the timestamp.

Throws:

SQLException - when an exception occurs reading from the resultSet.

writeTimestamp

protected void writeTimestamp(PreparedStatement preparedStatement,
 int position,
 Instant timestamp)
                       throws SQLException

Write a timestamp from a Instant to a data value suitable for the database scheme.

Parameters:

preparedStatement - the statement to update.

position - the position of the timestamp parameter in the statement.

timestamp - Instant to convert.

Throws:

SQLException - if modification of the statement fails.

readPayload

protected <T> T readPayload(ResultSet resultSet,
 String columnName)
                     throws SQLException

Reads a serialized object from the given resultSet at given columnIndex. The resultSet is positioned in the row that contains the data. This method must not change the row in the result set.

Parameters:

resultSet - The resultSet containing the stored data.

columnName - The name of the column containing the payload.

Returns:

an object describing the serialized data.

Throws:

SQLException - when an exception occurs reading from the resultSet.

domainEventFields

@Deprecated
protected String domainEventFields()

Deprecated.

in favor of EventSchema.domainEventFields()

Returns a comma separated list of domain event column names to select from an event or snapshot entry.

Returns:

comma separated domain event column names.

trackedEventFields

@Deprecated
protected String trackedEventFields()

Deprecated.

in favor of EventSchema.trackedEventFields()

Returns a comma separated list of tracked domain event column names to select from an event entry.

Returns:

comma separated tracked domain event column names.

schema

protected EventSchema schema()

Returns the EventSchema that defines the table and column names of event tables in the database.

Returns:

the event schema.

getConnection

protected Connection getConnection()

Returns a Connection to the database.

Returns:

a database Connection.

setGapTimeout

@Deprecated
public void setGapTimeout(int gapTimeout)

Deprecated.

Use the gapTimeout(int) in the builder() instead

Sets the amount of time until a 'gap' in a TrackingToken may be considered timed out. This setting will affect the cleaning process of gaps. Gaps that have timed out will be removed from Tracking Tokens to improve performance of reading events. Defaults to 60000 (1 minute).

Parameters:

gapTimeout - The amount of time, in milliseconds until a gap may be considered timed out.

setGapCleaningThreshold

@Deprecated
public void setGapCleaningThreshold(int gapCleaningThreshold)

Deprecated.

Use the gapCleaningThreshold(int) in the builder() instead

Sets the threshold of number of gaps in a token before an attempt to clean gaps up is taken. Defaults to 250.

Parameters:

gapCleaningThreshold - The number of gaps before triggering a cleanup.