org.apache.mahout.cf.taste.impl.similarity.jdbc

Class AbstractJDBCItemSimilarity

java.lang.Object

org.apache.mahout.cf.taste.impl.common.jdbc.AbstractJDBCComponent

org.apache.mahout.cf.taste.impl.similarity.jdbc.AbstractJDBCItemSimilarity

All Implemented Interfaces:

Refreshable, ItemSimilarity

Direct Known Subclasses:

SQL92JDBCItemSimilarity

public abstract class AbstractJDBCItemSimilarity
extends AbstractJDBCComponent
implements ItemSimilarity

An ItemSimilarity which draws pre-computed item-item similarities from a database table via JDBC.

Field Summary

Fields inherited from class org.apache.mahout.cf.taste.impl.common.jdbc.AbstractJDBCComponent

DEFAULT_DATASOURCE_NAME

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractJDBCItemSimilarity(DataSource dataSource, String getItemItemSimilaritySQL, String getAllSimilarItemIDsSQL)
protected	AbstractJDBCItemSimilarity(DataSource dataSource, String similarityTable, String itemAIDColumn, String itemBIDColumn, String similarityColumn, String getItemItemSimilaritySQL, String getAllSimilarItemIDsSQL)

Method Summary

Methods

Modifier and Type	Method and Description
long[]	allSimilarItemIDs(long itemID)
protected String	getItemAIDColumn()
protected String	getItemBIDColumn()
protected String	getSimilarityColumn()
protected String	getSimilarityTable()
double[]	itemSimilarities(long itemID1, long[] itemID2s)
double	itemSimilarity(long itemID1, long itemID2)
void	refresh(Collection<Refreshable> alreadyRefreshed)

Methods inherited from class org.apache.mahout.cf.taste.impl.common.jdbc.AbstractJDBCComponent

checkNotNullAndLog, checkNotNullAndLog, getFetchSize, lookupDataSource

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractJDBCItemSimilarity

protected AbstractJDBCItemSimilarity(DataSource dataSource,
                          String getItemItemSimilaritySQL,
                          String getAllSimilarItemIDsSQL)

AbstractJDBCItemSimilarity

protected AbstractJDBCItemSimilarity(DataSource dataSource,
                          String similarityTable,
                          String itemAIDColumn,
                          String itemBIDColumn,
                          String similarityColumn,
                          String getItemItemSimilaritySQL,
                          String getAllSimilarItemIDsSQL)

Method Detail

getSimilarityTable

protected String getSimilarityTable()

getItemAIDColumn

protected String getItemAIDColumn()

getItemBIDColumn

protected String getItemBIDColumn()

getSimilarityColumn

protected String getSimilarityColumn()

itemSimilarity

public double itemSimilarity(long itemID1,
                    long itemID2)
                      throws TasteException

Specified by:

itemSimilarity in interface ItemSimilarity

Throws:

TasteException

itemSimilarities

public double[] itemSimilarities(long itemID1,
                        long[] itemID2s)
                          throws TasteException

Specified by:

itemSimilarities in interface ItemSimilarity

Throws:

TasteException

allSimilarItemIDs

public long[] allSimilarItemIDs(long itemID)
                         throws TasteException

Specified by:

allSimilarItemIDs in interface ItemSimilarity

Throws:

TasteException

refresh

public void refresh(Collection<Refreshable> alreadyRefreshed)

Specified by:

refresh in interface Refreshable