Package org.springframework.data.cassandra.core.cql

Interface ReactiveStatementCallback<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 ReactiveStatementCallback<T>

Generic callback interface for code that operates on a CQL Statement. Allows to execute any number of operations on a single Statement, for example a single ReactiveSession.execute(Statement).

Used internally by ReactiveCqlTemplate, but also useful for application code.

Since:

2.0

Author:

Mark Paluch

Method Summary

Modifier and Type	Method	Description
org.reactivestreams.Publisher<T>	doInStatement(ReactiveSession session, com.datastax.oss.driver.api.core.cql.Statement<?> stmt)	Gets called by ReactiveCqlTemplate.execute(String) with an active Cassandra session.

Method Details

doInStatement

org.reactivestreams.Publisher<T> doInStatement(ReactiveSession session,
 com.datastax.oss.driver.api.core.cql.Statement<?> stmt)
                                        throws com.datastax.oss.driver.api.core.DriverException,
DataAccessException

Gets called by ReactiveCqlTemplate.execute(String) with an active Cassandra session. Does not need to care about closing the the session: this will all be handled by Spring's ReactiveCqlTemplate.

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(String, Class, Object...) etc. A thrown RuntimeException is treated as application exception, it gets propagated to the caller of the template.

Parameters:

session - active Cassandra session.

stmt - CQL Statement.

Returns:

a result object publisher.

Throws:

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

DataAccessException - in case of custom exceptions

See Also:

• ReactiveCqlTemplate.query(String, ReactiveResultSetExtractor)
• ReactiveCqlTemplate.query(Statement, ReactiveResultSetExtractor)