org.apache.metamodel.kafka

Class KafkaDataContext<K,V>

java.lang.Object

org.apache.metamodel.AbstractDataContext

org.apache.metamodel.QueryPostprocessDataContext

org.apache.metamodel.kafka.KafkaDataContext<K,V>

All Implemented Interfaces:

HasReadTypeConverters, DataContext, UpdateableDataContext

@InterfaceStability.Unstable
public class KafkaDataContext<K,V>
extends QueryPostprocessDataContext
implements UpdateableDataContext

Field Summary

Fields

Modifier and Type	Field and Description
static String	COLUMN_KEY
static String	COLUMN_OFFSET
static String	COLUMN_PARTITION
static String	COLUMN_TIMESTAMP
static String	COLUMN_VALUE
static String	SYSTEM_PROPERTY_CONSUMER_POLL_TIMEOUT

Fields inherited from class org.apache.metamodel.QueryPostprocessDataContext

INFORMATION_SCHEMA_NAME, SYSTEM_PROPERTY_CREATE_DEFAULT_TABLE_ALIAS

Constructor Summary

Constructors

Constructor and Description
KafkaDataContext(Class<K> keyClass, Class<V> valueClass, ConsumerAndProducerFactory consumerAndProducerFactory, Supplier<Collection<String>> topicSupplier)
KafkaDataContext(Class<K> keyClass, Class<V> valueClass, String bootstrapServers, Collection<String> topics)

Method Summary

Modifier and Type	Method and Description
UpdateSummary	executeUpdate(UpdateScript update) Submits an UpdateScript for execution on the DataContext.
protected Schema	getMainSchema()
protected String	getMainSchemaName()
protected DataSet	materializeMainSchemaTable(Table table, List<Column> columns, int maxRows) Executes a simple one-table query against a table in the main schema of the subclasses of this class.
protected DataSet	materializeMainSchemaTable(Table table, List<SelectItem> selectItems, List<FilterItem> whereItems, int firstRow, int maxRows) Execute a simple one-table query against a table in the main schema of the subclasses of this class.
protected DataSet	materializeMainSchemaTableFromConsumer(org.apache.kafka.clients.consumer.Consumer<K,V> consumer, List<SelectItem> selectItems, int offset, int maxRows)

Methods inherited from class org.apache.metamodel.QueryPostprocessDataContext

addConverter, executeCountQuery, executePrimaryKeyLookupQuery, executeQuery, getDefaultSchemaName, getSchemaByNameInternal, getSchemaNamesInternal, isMainSchemaTable, isScalarFunctionMaterialized, materializeFromItem, materializeMainSchemaTable, materializeMainSchemaTableSelect, materializeTable

Methods inherited from class org.apache.metamodel.AbstractDataContext

compileQuery, executeQuery, executeQuery, getColumnByQualifiedLabel, getDefaultSchema, getSchemaByName, getSchemaNames, getSchemas, getTableByQualifiedLabel, isQualifiedPathDelim, onSchemaCacheRefreshed, parseQuery, query, refreshSchemas

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.metamodel.DataContext

compileQuery, executeQuery, executeQuery, executeQuery, getColumnByQualifiedLabel, getDefaultSchema, getSchemaByName, getSchemaNames, getSchemas, getTableByQualifiedLabel, parseQuery, query, refreshSchemas

Field Detail

SYSTEM_PROPERTY_CONSUMER_POLL_TIMEOUT

public static final String SYSTEM_PROPERTY_CONSUMER_POLL_TIMEOUT

See Also:

Constant Field Values

COLUMN_PARTITION

public static final String COLUMN_PARTITION

See Also:

Constant Field Values

COLUMN_OFFSET

public static final String COLUMN_OFFSET

See Also:

Constant Field Values

COLUMN_TIMESTAMP

public static final String COLUMN_TIMESTAMP

See Also:

Constant Field Values

COLUMN_KEY

public static final String COLUMN_KEY

See Also:

Constant Field Values

COLUMN_VALUE

public static final String COLUMN_VALUE

See Also:

Constant Field Values

Constructor Detail

KafkaDataContext

public KafkaDataContext(Class<K> keyClass,
                        Class<V> valueClass,
                        String bootstrapServers,
                        Collection<String> topics)

KafkaDataContext

public KafkaDataContext(Class<K> keyClass,
                        Class<V> valueClass,
                        ConsumerAndProducerFactory consumerAndProducerFactory,
                        Supplier<Collection<String>> topicSupplier)

Method Detail

getMainSchema

protected Schema getMainSchema()
                        throws MetaModelException

Specified by:

getMainSchema in class QueryPostprocessDataContext

Returns:

the main schema that subclasses of this class produce

Throws:

MetaModelException

getMainSchemaName

protected String getMainSchemaName()
                            throws MetaModelException

Specified by:

getMainSchemaName in class QueryPostprocessDataContext

Returns:

the name of the main schema that subclasses of this class produce

Throws:

MetaModelException

materializeMainSchemaTable

protected DataSet materializeMainSchemaTable(Table table,
                                             List<Column> columns,
                                             int maxRows)

Description copied from class: QueryPostprocessDataContext

Executes a simple one-table query against a table in the main schema of the subclasses of this class.

Specified by:

materializeMainSchemaTable in class QueryPostprocessDataContext

Parameters:

table - the table to query

columns - the columns of the table to query

maxRows - the maximum amount of rows needed or -1 if all rows are wanted.

Returns:

a dataset with the raw table/column content.

materializeMainSchemaTableFromConsumer

protected DataSet materializeMainSchemaTableFromConsumer(org.apache.kafka.clients.consumer.Consumer<K,V> consumer,
                                                         List<SelectItem> selectItems,
                                                         int offset,
                                                         int maxRows)

materializeMainSchemaTable

protected DataSet materializeMainSchemaTable(Table table,
                                             List<SelectItem> selectItems,
                                             List<FilterItem> whereItems,
                                             int firstRow,
                                             int maxRows)

Description copied from class: QueryPostprocessDataContext

Execute a simple one-table query against a table in the main schema of the subclasses of this class. This default implementation will delegate to QueryPostprocessDataContext.materializeMainSchemaTable(Table, List, int, int) and apply WHERE item filtering afterwards.

Overrides:

materializeMainSchemaTable in class QueryPostprocessDataContext

Returns:

executeUpdate

public UpdateSummary executeUpdate(UpdateScript update)

Description copied from interface: UpdateableDataContext

Submits an UpdateScript for execution on the DataContext. Since implementations of the DataContext vary quite a lot, there is no golden rule as to how an update script will be executed. But the implementors should strive towards handling an UpdateScript as a single transactional change to the data store.

Specified by:

executeUpdate in interface UpdateableDataContext

Parameters:

update - the update script to execute

Returns:

a summary of the updates performed