Package com.opencqrs.esdb.client

Class EsdbClient

java.lang.Object

com.opencqrs.esdb.client.EsdbClient

All Implemented Interfaces:

AutoCloseable

public final class EsdbClient
extends Object
implements AutoCloseable

Client SDK for the EventSourcingDB.

Constructor Summary

Constructors

Constructor	Description
EsdbClient(URI serverUri, String accessToken, Marshaller marshaller, HttpClient.Builder httpClientBuilder)

Method Summary

Modifier and Type	Method	Description
void	authenticate()	Authenticates against the configured event store, ensuring the correct api token has been configured.
void	close()
Health	health()	Checks the healthiness of the configured event store.
void	observe(String subject, Set<Option> options, Consumer<Event> eventConsumer)	Streams existing Events from the underlying event store, waiting for any new events to be published.
void	ping()	Pings the configured event store, ensuring the server is running
void	query(String query, RowHandler rowHandler, ErrorHandler errorHandler)	Queries the underlying event store using EventQL.
List<Event>	read(String subject, Set<Option> options)	Reads existing Events from the underlying event store.
void	read(String subject, Set<Option> options, Consumer<Event> eventConsumer)	Reads existing Events from the underlying event store.
List<Event>	write(List<EventCandidate> eventCandidates, List<Precondition> preconditions)	Publishes the given EventCandidates to the underlying event store.

Methods inherited from class java.lang.Object

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

Constructor Details

EsdbClient

public EsdbClient(URI serverUri,
 String accessToken,
 Marshaller marshaller,
 HttpClient.Builder httpClientBuilder)

Method Details

ping

public void ping()
          throws ClientException

Pings the configured event store, ensuring the server is running

Throws:

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

authenticate

public void authenticate()
                  throws ClientException

Authenticates against the configured event store, ensuring the correct api token has been configured.

Throws:

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code, e.g. 401 if not authenticated successfully

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

health

public Health health()
              throws ClientException

Checks the healthiness of the configured event store.

Returns:

the health status

Throws:

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

write

public List<Event> write(List<EventCandidate> eventCandidates,
 List<Precondition> preconditions)
                  throws ClientException

Publishes the given EventCandidates to the underlying event store. The given preconditions must be fulfilled in order for the publication to be applied. The publication is guaranteed to be an atomic operation, that is event candidates will be published all or nothing, if preconditions hold.

Parameters:

eventCandidates - the candidate events to be published together

preconditions - preconditions that must be fulfilled, otherwise ClientException.HttpException.HttpClientException with status code 409 will be thrown

Returns:

a list of Events with all fields populated, except for Event.hash()

Throws:

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

observe

public void observe(String subject,
 Set<Option> options,
 Consumer<Event> eventConsumer)
             throws ClientException

Streams existing Events from the underlying event store, waiting for any new events to be published. This method will block infinitely, if no exception or error occurs. Any observed event will be passed the given event consumer synchronously, to maintain the natural event order.

In order to observe all events from the underlying event store subject should be set to / together with Option.Recursive.

Parameters:

subject - the subject to observe

options - a set of options controlling the result set

eventConsumer - a consumer callback for the observed events

Throws:

ClientException.InvalidUsageException - in case of an invalid Option used

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

read

public void read(String subject,
 Set<Option> options,
 Consumer<Event> eventConsumer)
          throws ClientException

Reads existing Events from the underlying event store. All events will be passed the given event consumer synchronously, to maintain the natural event order.

Parameters:

subject - the subject to read from

options - a set of options controlling the result set

eventConsumer - a consumer callback for the read events

Throws:

ClientException.InvalidUsageException - in case of an invalid Option used

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

read

public List<Event> read(String subject,
 Set<Option> options)
                 throws ClientException

Reads existing Events from the underlying event store.

Parameters:

subject - the subject to read from

options - a set of options controlling the result set

Returns:

a list of Events, may be empty

Throws:

ClientException.InvalidUsageException - in case of an invalid Option used

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors, typically caused by the associated Marshaller

ClientException

query

public void query(String query,
 RowHandler rowHandler,
 ErrorHandler errorHandler)
           throws ClientException

Queries the underlying event store using EventQL.

Parameters:

query - a valid query

rowHandler - callback for successfully queried and transformed rows (called per row)

errorHandler - callback for non successfully queried or transformed rows (called per row)

Throws:

ClientException.TransportException - in case of connection or network errors

ClientException.HttpException - in case of errors depending on the HTTP status code

ClientException.MarshallingException - in case of serialization errors regarding the request not the individual row, typically caused by the associated Marshaller

ClientException

See Also:

• RowHandler
• ErrorHandler

close

public void close()
           throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception