org.springframework.data.cassandra.core.cql

Interface ReactiveSessionCallback<T>

Type Parameters:

T -

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ReactiveSessionCallback<T>

Generic callback interface for code that operates on a CQL ReactiveSession. Allows to execute any number of operations on a single ReactiveSession, using any type and number of Statements.

This is particularly useful for delegating to existing data access code that expects a ReactiveSession to work on and throws DriverException. For newly written code, it is strongly recommended to use CqlTemplate's more specific operations, for example a query or update variant.

Since:

2.0

Author:

Mark Paluch

See Also:

ReactiveCqlTemplate.execute(ReactiveSessionCallback)

Method Summary

Modifier and Type	Method and Description
org.reactivestreams.Publisher<T>	doInSession(ReactiveSession session) Gets called by ReactiveCqlTemplate.execute(ReactiveSessionCallback) with an active Cassandra session.

Method Detail

doInSession

org.reactivestreams.Publisher<T> doInSession(ReactiveSession session)
                                      throws com.datastax.driver.core.exceptions.DriverException,
                                             DataAccessException

Gets called by ReactiveCqlTemplate.execute(ReactiveSessionCallback) with an active Cassandra session. Does not need to care about activating or closing the ReactiveSession.

Allows for returning a result object created within the callback, i.e. a domain object or a collection of domain objects. Note that there's special support for single step actions: see ReactiveCqlTemplate.queryForObject(Statement, Class) etc. A thrown RuntimeException is treated as application exception: it gets propagated to the caller of the template.

Parameters:

session - active Cassandra session.

Returns:

a result object publisher.

Throws:

com.datastax.driver.core.exceptions.DriverException - if thrown by a session method, to be auto-converted to a DataAccessException.

DataAccessException - in case of custom exceptions.

See Also:

ReactiveCqlTemplate.execute(ReactivePreparedStatementCreator, ReactivePreparedStatementCallback)