org.grouplens.lenskit.data.dao

Class MapItemNameDAO

java.lang.Object

org.grouplens.lenskit.data.dao.MapItemNameDAO

All Implemented Interfaces:

Serializable, ItemDAO, ItemNameDAO

@Shareable
public class MapItemNameDAO
extends Object
implements ItemNameDAO, ItemDAO, Serializable

An item name DAO backed by a map of item IDs to names.

Since:

2.2

See Also:

ItemNameDAO, Serialized Form

Constructor Summary

Constructors

Constructor and Description
MapItemNameDAO(Map<Long,String> items)

Method Summary

Modifier and Type	Method and Description
static MapItemNameDAO	fromCSVFile(File file) Read an item list DAO from a file.
LongSet	getItemIds() Get all known item IDs.
String	getItemName(long item) Get the name for an item.

Methods inherited from class java.lang.Object

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

Constructor Detail

MapItemNameDAO

public MapItemNameDAO(Map<Long,String> items)

Method Detail

getItemIds

@Nullable
public LongSet getItemIds()

Description copied from interface: ItemDAO

Get all known item IDs.

Specified by:

getItemIds in interface ItemDAO

Returns:

The set of known item IDs.

getItemName

@Nullable
public String getItemName(long item)

Description copied from interface: ItemNameDAO

Get the name for an item.

Specified by:

getItemName in interface ItemNameDAO

Parameters:

item - The item ID.

Returns:

A display name for the item, or null if the item is unknown or has no name.

fromCSVFile

public static MapItemNameDAO fromCSVFile(File file)
                                  throws IOException

Read an item list DAO from a file.

Parameters:

file - A file of item IDs, one per line.

Returns:

The item list DAO.

Throws:

IOException - if there is an error reading the list of items.