org.springframework.data.cassandra.core.cql

Class CassandraAccessor

java.lang.Object

org.springframework.data.cassandra.core.cql.CassandraAccessor

All Implemented Interfaces:

InitializingBean

Direct Known Subclasses:

AsyncCqlTemplate, CqlTemplate

public class CassandraAccessor
extends Object
implements InitializingBean

CassandraAccessor provides access to a Cassandra SessionFactory and the CassandraExceptionTranslator.

Classes providing a higher abstraction level usually extend CassandraAccessor to provide a richer set of functionality on top of a SessionFactory using CqlSession.

Author:

David Webb, Mark Paluch, John Blum, Tomasz Lelek

See Also:

InitializingBean, CqlSession

Field Summary

Fields

Modifier and Type	Field and Description
protected org.slf4j.Logger	logger Logger available to subclasses

Constructor Summary

Constructors

Constructor and Description
CassandraAccessor()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet() Ensures the Cassandra CqlSession and exception translator has been propertly set.
protected com.datastax.oss.driver.api.core.cql.Statement<?>	applyStatementSettings(com.datastax.oss.driver.api.core.cql.Statement<?> statement) Prepare the given CQL Statement applying statement settings such as page size and consistency level.
com.datastax.oss.driver.api.core.ConsistencyLevel	getConsistencyLevel()
CqlExceptionTranslator	getExceptionTranslator() Return the exception translator used by this template to translate Cassandra specific Exceptions into Spring DAO's Exception Hierarchy.
ExecutionProfileResolver	getExecutionProfileResolver()
int	getFetchSize() Deprecated. since 3.0, use getPageSize().
com.datastax.oss.driver.api.core.CqlIdentifier	getKeyspace()
int	getPageSize()
com.datastax.oss.driver.api.core.ConsistencyLevel	getSerialConsistencyLevel()
com.datastax.oss.driver.api.core.CqlSession	getSession() Deprecated. since 2.0. This class uses a SessionFactory to dispatch CQL calls amongst different CqlSessions during its lifecycle.
SessionFactory	getSessionFactory() Returns the Cassandra SessionFactory used by this template to perform Cassandra data access operations.
protected RowMapper<Map<String,Object>>	newColumnMapRowMapper() Create a new RowMapper for reading columns as key-value pairs.
protected PreparedStatementBinder	newPreparedStatementBinder(Object[] args) Create a new arg-based PreparedStatementSetter using the args passed in.
protected <T> RowMapper<T>	newSingleColumnRowMapper(Class<T> requiredType) Create a new RowMapper for reading result objects from a single column.
protected com.datastax.oss.driver.api.core.cql.SimpleStatement	newStatement(String cql) Create a SimpleStatement given cql.
void	setConsistencyLevel(com.datastax.oss.driver.api.core.ConsistencyLevel consistencyLevel) Set the consistency level for this template.
void	setExceptionTranslator(CqlExceptionTranslator exceptionTranslator) Sets the exception translator used by this template to translate Cassandra specific Exceptions into Spring DAO's Exception Hierarchy.
void	setExecutionProfile(String profileName) Set the driver execution profile for this template.
void	setExecutionProfileResolver(ExecutionProfileResolver executionProfileResolver) Set the ExecutionProfileResolver for this template.
void	setFetchSize(int fetchSize) Deprecated. since 3.0, use setPageSize(int)
void	setKeyspace(com.datastax.oss.driver.api.core.CqlIdentifier keyspace) Set the keyspace to be applied on statement-level for this template.
void	setPageSize(int fetchSize) Set the page size for this template.
void	setSerialConsistencyLevel(com.datastax.oss.driver.api.core.ConsistencyLevel consistencyLevel) Set the serial consistency level for this template.
void	setSession(com.datastax.oss.driver.api.core.CqlSession session) Sets the Cassandra CqlSession used by this template to perform Cassandra data access operations.
void	setSessionFactory(SessionFactory sessionFactory) Sets the Cassandra SessionFactory used by this template to perform Cassandra data access operations.
protected static String	toCql(Object cqlProvider) Determine CQL from potential provider object.
protected DataAccessException	translate(String task, String cql, RuntimeException ex) Translate the given RuntimeException into a generic DataAccessException.
protected DataAccessException	translateExceptionIfPossible(RuntimeException ex) Translate the given RuntimeException into a generic DataAccessException.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final org.slf4j.Logger logger

Logger available to subclasses

Constructor Detail

CassandraAccessor

public CassandraAccessor()

Method Detail

afterPropertiesSet

public void afterPropertiesSet()

Ensures the Cassandra CqlSession and exception translator has been propertly set.

Specified by:

afterPropertiesSet in interface InitializingBean

setConsistencyLevel

public void setConsistencyLevel(@Nullable
                                com.datastax.oss.driver.api.core.ConsistencyLevel consistencyLevel)

Set the consistency level for this template. Consistency level defines the number of nodes involved into query processing. Relaxed consistency level settings use fewer nodes but eventual consistency is more likely to occur while a higher consistency level involves more nodes to obtain results with a higher consistency guarantee.

See Also:

Statement.setConsistencyLevel(ConsistencyLevel), RetryPolicy

getConsistencyLevel

@Nullable
public com.datastax.oss.driver.api.core.ConsistencyLevel getConsistencyLevel()

Returns:

the ConsistencyLevel specified for this template.

setExceptionTranslator

public void setExceptionTranslator(CqlExceptionTranslator exceptionTranslator)

Sets the exception translator used by this template to translate Cassandra specific Exceptions into Spring DAO's Exception Hierarchy.

Parameters:

exceptionTranslator - exception translator to set; must not be null.

See Also:

CqlExceptionTranslator

getExceptionTranslator

public CqlExceptionTranslator getExceptionTranslator()

Return the exception translator used by this template to translate Cassandra specific Exceptions into Spring DAO's Exception Hierarchy.

Returns:

the Cassandra exception translator.

See Also:

CqlExceptionTranslator

setExecutionProfile

public void setExecutionProfile(String profileName)

Set the driver execution profile for this template.

Since:

3.0

See Also:

Statement.setExecutionProfileName(String), ExecutionProfileResolver

setExecutionProfileResolver

public void setExecutionProfileResolver(ExecutionProfileResolver executionProfileResolver)

Set the ExecutionProfileResolver for this template.

Since:

3.0

See Also:

DriverExecutionProfile, ExecutionProfileResolver

getExecutionProfileResolver

public ExecutionProfileResolver getExecutionProfileResolver()

Returns:

the ExecutionProfileResolver specified for this template.

Since:

3.0

setFetchSize

@Deprecated
public void setFetchSize(int fetchSize)

Deprecated. since 3.0, use setPageSize(int)

Set the fetch size for this template. This is important for processing large result sets: Setting this higher than the default value will increase processing speed at the cost of memory consumption; setting this lower can avoid transferring row data that will never be read by the application. Default is -1, indicating to use the CQL driver's default configuration (i.e. to not pass a specific fetch size setting on to the driver).

See Also:

StatementBuilder.setPageSize(int)

getFetchSize

@Deprecated
public int getFetchSize()

Deprecated. since 3.0, use getPageSize().

Returns:

the fetch size specified for this template.

setKeyspace

public void setKeyspace(com.datastax.oss.driver.api.core.CqlIdentifier keyspace)

Set the keyspace to be applied on statement-level for this template. If not set, the default CqlSession keyspace will be used.

Parameters:

keyspace - the keyspace to apply, must not be null.

Since:

3.1

See Also:

SimpleStatement.setKeyspace(CqlIdentifier), BatchStatement.setKeyspace(CqlIdentifier)

getKeyspace

@Nullable
public com.datastax.oss.driver.api.core.CqlIdentifier getKeyspace()

Returns:

the keyspace to be applied on statement-level for this template.

Since:

3.1

setPageSize

public void setPageSize(int fetchSize)

Set the page size for this template. This is important for processing large result sets: Setting this higher than the default value will increase processing speed at the cost of memory consumption; setting this lower can avoid transferring row data that will never be read by the application. Default is -1, indicating to use the CQL driver's default configuration (i.e. to not pass a specific page size setting on to the driver).

See Also:

StatementBuilder.setPageSize(int)

getPageSize

public int getPageSize()

Returns:

the page size specified for this template.

setSerialConsistencyLevel

public void setSerialConsistencyLevel(@Nullable
                                      com.datastax.oss.driver.api.core.ConsistencyLevel consistencyLevel)

Set the serial consistency level for this template.

Since:

3.0

See Also:

Statement.setSerialConsistencyLevel(ConsistencyLevel), ConsistencyLevel

getSerialConsistencyLevel

@Nullable
public com.datastax.oss.driver.api.core.ConsistencyLevel getSerialConsistencyLevel()

Returns:

the serial ConsistencyLevel specified for this template.

Since:

3.0

setSession

public void setSession(com.datastax.oss.driver.api.core.CqlSession session)

Sets the Cassandra CqlSession used by this template to perform Cassandra data access operations. The session will replace the current getSessionFactory() with DefaultSessionFactory.

Parameters:

session - Cassandra CqlSession used by this template, must not benull.

See Also:

CqlSession, DefaultSessionFactory

getSession

@Deprecated
public com.datastax.oss.driver.api.core.CqlSession getSession()

Deprecated. since 2.0. This class uses a SessionFactory to dispatch CQL calls amongst different CqlSessions during its lifecycle.

Returns the Cassandra CqlSession from SessionFactory used by this template to perform Cassandra data access operations.

Returns:

the Cassandra CqlSession used by this template.

See Also:

CqlSession

setSessionFactory

public void setSessionFactory(SessionFactory sessionFactory)

Sets the Cassandra SessionFactory used by this template to perform Cassandra data access operations.

Parameters:

sessionFactory - Cassandra CqlSession used by this template. Must not benull.

Since:

2.0

See Also:

CqlSession

getSessionFactory

@Nullable
public SessionFactory getSessionFactory()

Returns the Cassandra SessionFactory used by this template to perform Cassandra data access operations.

Returns:

the Cassandra SessionFactory used by this template.

Since:

2.0

See Also:

SessionFactory

newStatement

protected com.datastax.oss.driver.api.core.cql.SimpleStatement newStatement(String cql)

Create a SimpleStatement given cql.

Parameters:

cql - the CQL query.

Returns:

the SimpleStatement to use.

Since:

3.0

applyStatementSettings

protected com.datastax.oss.driver.api.core.cql.Statement<?> applyStatementSettings(com.datastax.oss.driver.api.core.cql.Statement<?> statement)

Prepare the given CQL Statement applying statement settings such as page size and consistency level.

Parameters:

statement - the CQL Statement to prepare

See Also:

setConsistencyLevel(ConsistencyLevel), setSerialConsistencyLevel(ConsistencyLevel), setPageSize(int), setExecutionProfile(String), setExecutionProfileResolver(ExecutionProfileResolver)

translateExceptionIfPossible

@Nullable
protected DataAccessException translateExceptionIfPossible(RuntimeException ex)

Translate the given RuntimeException into a generic DataAccessException.

The returned DataAccessException is supposed to contain the original RuntimeException as root cause. However, client code may not generally rely on this due to DataAccessExceptions possibly being caused by other resource APIs as well. That said, a getRootCause() instanceof DataAccessException check (and subsequent cast) is considered reliable when expecting Cassandra-based access to have happened.

Parameters:

ex - the offending RuntimeException

Returns:

the DataAccessException, wrapping the RuntimeException

See Also:

Consistent exception hierarchy, DataAccessException

translate

protected DataAccessException translate(String task,
                                        @Nullable
                                        String cql,
                                        RuntimeException ex)

Translate the given RuntimeException into a generic DataAccessException.

The returned DataAccessException is supposed to contain the original RuntimeException as root cause. However, client code may not generally rely on this due to DataAccessExceptions possibly being caused by other resource APIs as well. That said, a getRootCause() instanceof DataAccessException check (and subsequent cast) is considered reliable when expecting Cassandra-based access to have happened.

Parameters:

task - readable text describing the task being attempted

cql - CQL query or update that caused the problem (may be null)

ex - the offending RuntimeException

Returns:

the DataAccessException, wrapping the RuntimeException

See Also:

NestedRuntimeException.getRootCause(), Consistent exception hierarchy

newPreparedStatementBinder

protected PreparedStatementBinder newPreparedStatementBinder(Object[] args)

Create a new arg-based PreparedStatementSetter using the args passed in. By default, we'll create an ArgumentPreparedStatementBinder. This method allows for the creation to be overridden by subclasses.

Parameters:

args - object array with arguments

Returns:

the new PreparedStatementBinder to use

newColumnMapRowMapper

protected RowMapper<Map<String,Object>> newColumnMapRowMapper()

Create a new RowMapper for reading columns as key-value pairs.

Returns:

the RowMapper to use

See Also:

ColumnMapRowMapper

newSingleColumnRowMapper

protected <T> RowMapper<T> newSingleColumnRowMapper(Class<T> requiredType)

Create a new RowMapper for reading result objects from a single column.

Parameters:

requiredType - the type that each result object is expected to match

Returns:

the RowMapper to use

See Also:

SingleColumnRowMapper

toCql

@Nullable
protected static String toCql(@Nullable
                                        Object cqlProvider)

Determine CQL from potential provider object.

Parameters:

cqlProvider - object that's potentially a CqlProvider

Returns:

the CQL string, or null

See Also:

CqlProvider