org.springframework.data.cassandra.core.cql.session

Class DefaultBridgedReactiveSession

java.lang.Object

org.springframework.data.cassandra.core.cql.session.DefaultBridgedReactiveSession

All Implemented Interfaces:

Closeable, AutoCloseable, ReactiveSession

public class DefaultBridgedReactiveSession
extends Object
implements ReactiveSession

Default implementation of a ReactiveSession. This implementation bridges asynchronous Session methods to reactive execution patterns.

Calls are deferred until a subscriber subscribes to the resulting Publisher. The calls are executed by subscribing to ListenableFuture and returning the result as calls complete.

Elements are emitted on netty EventLoop threads. ResultSet allows asynchronous requesting of subsequent pages. The next page is requested after emitting all elements of the previous page. However, this is an intermediate solution until Datastax can provide a fully reactive driver.

All CQL operations performed by this class are logged at debug level, using org.springframework.data.cassandra.core.cql.DefaultBridgedReactiveSession as log category.

Since:

2.0

Author:

Mark Paluch

See Also:

Mono, ReactiveResultSet, Scheduler, ReactiveSession

Constructor Summary

Constructors

Constructor and Description
DefaultBridgedReactiveSession(com.datastax.driver.core.Session session) Create a new DefaultBridgedReactiveSession for a Session.
DefaultBridgedReactiveSession(com.datastax.driver.core.Session session, reactor.core.scheduler.Scheduler scheduler) Deprecated. since 2.1. Use DefaultBridgedReactiveSession(Session) as a Scheduler is no longer required to off-load ResultSet's blocking behavior.

Method Summary

Modifier and Type	Method and Description
void	close() Initiates a shutdown of this session instance and blocks until that shutdown completes.
reactor.core.publisher.Mono<ReactiveResultSet>	execute(com.datastax.driver.core.Statement statement) Executes the provided query.
reactor.core.publisher.Mono<ReactiveResultSet>	execute(String query) Executes the provided query.
reactor.core.publisher.Mono<ReactiveResultSet>	execute(String query, Map<String,Object> values) Executes the provided query using the provided named values.
reactor.core.publisher.Mono<ReactiveResultSet>	execute(String query, Object... values) Executes the provided query using the provided values.
com.datastax.driver.core.Cluster	getCluster() Returns the Cluster object this session is part of.
boolean	isClosed() Whether this Session instance has been closed.
reactor.core.publisher.Mono<com.datastax.driver.core.PreparedStatement>	prepare(com.datastax.driver.core.RegularStatement statement) Prepares the provided query.
reactor.core.publisher.Mono<com.datastax.driver.core.PreparedStatement>	prepare(String query) Prepares the provided query string.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultBridgedReactiveSession

public DefaultBridgedReactiveSession(com.datastax.driver.core.Session session)

Create a new DefaultBridgedReactiveSession for a Session.

Parameters:

session - must not be null.

Since:

2.1

DefaultBridgedReactiveSession

@Deprecated
public DefaultBridgedReactiveSession(com.datastax.driver.core.Session session,
                                                 reactor.core.scheduler.Scheduler scheduler)

Deprecated. since 2.1. Use DefaultBridgedReactiveSession(Session) as a Scheduler is no longer required to off-load ResultSet's blocking behavior.

Create a new DefaultBridgedReactiveSession for a Session and Scheduler.

Parameters:

session - must not be null.

scheduler - must not be null.

Method Detail

isClosed

public boolean isClosed()

Description copied from interface: ReactiveSession

Whether this Session instance has been closed.

Note that this method returns true as soon as the closing of this Session has started but it does not guarantee that the closing is done. If you want to guarantee that the closing is done, you can call close() and wait until it returns (or call the get method on closeAsync() with a very short timeout and check this doesn't timeout).

Specified by:

isClosed in interface ReactiveSession

Returns:

true if this Session instance has been closed, false otherwise.

getCluster

public com.datastax.driver.core.Cluster getCluster()

Description copied from interface: ReactiveSession

Returns the Cluster object this session is part of.

Specified by:

getCluster in interface ReactiveSession

Returns:

the Cluster object this session is part of.

execute

public reactor.core.publisher.Mono<ReactiveResultSet> execute(String query)

Description copied from interface: ReactiveSession

Executes the provided query.

This is a convenience method for execute(new SimpleStatement(query)).

Specified by:

execute in interface ReactiveSession

Parameters:

query - the CQL query to execute.

Returns:

the result of the query. That result will never be null but can be empty (and will be for any non SELECT query).

execute

public reactor.core.publisher.Mono<ReactiveResultSet> execute(String query,
                                                              Object... values)

Description copied from interface: ReactiveSession

Executes the provided query using the provided values.

This is a convenience method for execute(new SimpleStatement(query, values)).

Specified by:

execute in interface ReactiveSession

Parameters:

query - the CQL query to execute.

values - values required for the execution of query. See SimpleStatement#SimpleStatement(String, Object...) for more details.

Returns:

the result of the query. That result will never be null but can be empty (and will be for any non SELECT query).

execute

public reactor.core.publisher.Mono<ReactiveResultSet> execute(String query,
                                                              Map<String,Object> values)

Description copied from interface: ReactiveSession

Executes the provided query using the provided named values.

This is a convenience method for execute(new SimpleStatement(query, values)).

Specified by:

execute in interface ReactiveSession

Parameters:

query - the CQL query to execute.

values - values required for the execution of query. See SimpleStatement#SimpleStatement(String, Map) for more details.

Returns:

the result of the query. That result will never be null but can be empty (and will be for any non SELECT query).

execute

public reactor.core.publisher.Mono<ReactiveResultSet> execute(com.datastax.driver.core.Statement statement)

Description copied from interface: ReactiveSession

Executes the provided query.

This method blocks until at least some result has been received from the database. However, for SELECT queries, it does not guarantee that the result has been received in full. But it does guarantee that some response has been received from the database, and in particular guarantees that if the request is invalid, an exception will be thrown by this method.

Specified by:

execute in interface ReactiveSession

Parameters:

statement - the CQL query to execute (that can be any Statement).

Returns:

the result of the query. That result will never be null but can be empty (and will be for any non SELECT query).

prepare

public reactor.core.publisher.Mono<com.datastax.driver.core.PreparedStatement> prepare(String query)

Description copied from interface: ReactiveSession

Prepares the provided query string.

Specified by:

prepare in interface ReactiveSession

Parameters:

query - the CQL query string to prepare

Returns:

the prepared statement corresponding to query.

prepare

public reactor.core.publisher.Mono<com.datastax.driver.core.PreparedStatement> prepare(com.datastax.driver.core.RegularStatement statement)

Description copied from interface: ReactiveSession

Prepares the provided query.

This method behaves like ReactiveSession.prepare(String), but note that the resulting PreparedStatement will inherit the query properties set on statement. Concretely, this means that in the following code:

 RegularStatement toPrepare = new SimpleStatement("SELECT * FROM test WHERE k=?")
                .setConsistencyLevel(ConsistencyLevel.QUORUM);
 PreparedStatement prepared = session.prepare(toPrepare);
 session.execute(prepared.bind("someValue"));
 

the final execution will be performed with Quorum consistency.

Please note that if the same CQL statement is prepared more than once, all calls to this method will return the same PreparedStatement object but the method will still apply the properties of the prepared Statement to this object.

Specified by:

prepare in interface ReactiveSession

Parameters:

statement - the statement to prepare

Returns:

the prepared statement corresponding to statement.

close

public void close()

Description copied from interface: ReactiveSession

Initiates a shutdown of this session instance and blocks until that shutdown completes.

This method is a shortcut for closeAsync().get().

Note that this method does not close the corresponding Cluster instance (which holds additional resources, in particular internal executors that must be shut down in order for the client program to terminate). If you want to do so, use Cluster.close(), but note that it will close all sessions created from that cluster.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ReactiveSession