org.grouplens.lenskit.data.text

Class TextEventDAO

java.lang.Object

org.grouplens.lenskit.data.text.TextEventDAO

All Implemented Interfaces:

EventDAO, Describable

@ThreadSafe
public class TextEventDAO
extends Object
implements EventDAO, Describable

DAO that reads events from a text file, one per line. Events are formatted according to an EventFormat.

Since:

2.2

Constructor Summary

Constructors

Constructor and Description
TextEventDAO(File file, EventFormat format)

Method Summary

Modifier and Type	Method and Description
static TextEventDAO	create(File inputFile, EventFormat format)
static TextEventDAO	create(File inputFile, EventFormat format, CompressionMode comp)
void	describeTo(DescriptionWriter descr) Write this class's description to a sink.
static TextEventDAO	ratings(File file, String delim) Open a rating DAO with the default layout and automatic compression.
static TextEventDAO	ratings(File file, String delim, CompressionMode mode) Open a potentially-compressed file of ratings.
Cursor<Event>	streamEvents() Stream all events.
<E extends Event> Cursor<E>	streamEvents(Class<E> type) Stream all events of a given type.
<E extends Event> Cursor<E>	streamEvents(Class<E> type, SortOrder order) Stream all events of a given type in a specified order.

Methods inherited from class java.lang.Object

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

Constructor Detail

TextEventDAO

@Inject
public TextEventDAO(@EventFile
                            File file,
                            EventFormat format)

Method Detail

ratings

public static TextEventDAO ratings(File file,
                                   String delim)

Open a rating DAO with the default layout and automatic compression.

Parameters:

file - The file.

delim - The delimiter.

Returns:

A DAO that parses ratings from file using DelimitedColumnEventFormat.

See Also:

ratings(File, String, org.grouplens.lenskit.util.io.CompressionMode)

ratings

public static TextEventDAO ratings(File file,
                                   String delim,
                                   CompressionMode mode)

Open a potentially-compressed file of ratings. It uses the default layout:

1. User
2. Item
3. Rating
4. Optional timestamp

Parameters:

file - The file to open.

delim - The delimiter.

mode - The compression mode.

Returns:

A text event DAO.

create

public static TextEventDAO create(File inputFile,
                                  EventFormat format)

create

public static TextEventDAO create(File inputFile,
                                  EventFormat format,
                                  CompressionMode comp)

streamEvents

public Cursor<Event> streamEvents()

Description copied from interface: EventDAO

Stream all events.

Specified by:

streamEvents in interface EventDAO

Returns:

A cursor over all events.

streamEvents

public <E extends Event> Cursor<E> streamEvents(Class<E> type)

Description copied from interface: EventDAO

Stream all events of a given type.

Specified by:

streamEvents in interface EventDAO

Parameters:

type - The event type.

Returns:

A cursor over all events.

streamEvents

public <E extends Event> Cursor<E> streamEvents(Class<E> type,
                                                SortOrder order)

Description copied from interface: EventDAO

Stream all events of a given type in a specified order.

Specified by:

streamEvents in interface EventDAO

Parameters:

type - The event type.

order - The order.

Returns:

A cursor over all events.

describeTo

public void describeTo(DescriptionWriter descr)

Description copied from interface: Describable

Write this class's description to a sink. Anything relevant to this object's identity should be digested; the idea is that, barring hash collisions, two objects with the same digest are equivalent. Used for things like deterministically generating cache file names.

Specified by:

describeTo in interface Describable

Parameters:

descr - The description writer to use.