org.lenskit.data.ratings

Class Rating

java.lang.Object

org.lenskit.data.entities.AbstractEntity

org.lenskit.data.entities.AbstractBeanEntity

org.lenskit.data.ratings.Rating

All Implemented Interfaces:

java.io.Serializable, Entity, Preference, Describable

Direct Known Subclasses:

Rating.WithTimestamp

@BuiltBy(value=RatingBuilder.class)
 @DefaultEntityType(value="rating")
public class Rating
extends AbstractBeanEntity
implements Preference, java.io.Serializable

A user rating an item. A rating is an expression of preference, in the form of a real-valued rating, for an item by a user. Ratings are also used to represent un-rate events, if the system supports them; these are represented by a rating value of Double.NaN.

To create a rating, use RatingBuilder. The newBuilder() method will create a rating builder.

See Also:

Serialized Form

Compatibility

Public

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Rating.WithTimestamp

Nested classes/interfaces inherited from class org.lenskit.data.entities.AbstractBeanEntity

AbstractBeanEntity.BeanAttributeGetter, AbstractBeanEntity.BeanEntityLayout

Field Summary

Fields

Modifier and Type	Field and Description
static AttributeSet	ATTRIBUTES
static EntityType	ENTITY_TYPE

Fields inherited from class org.lenskit.data.entities.AbstractEntity

id, type

Method Summary

Modifier and Type	Method and Description
RatingBuilder	copyBuilder() Create a new rating builder that will build a copy of this rating.
static Rating	create(long uid, long iid, double rating) Deprecated. Use EntityFactory.rating(long, long, double)
static Rating	create(long uid, long iid, double rating, long ts) Deprecated. Use EntityFactory.rating(long, long, double, long)
boolean	equals(java.lang.Object obj)
long	getItemId() Get the ID of the item the preference is for.
long	getTimestamp()
long	getUserId() Get the ID of the user whose preference this is.
double	getValue() Get the rating value.
static RatingBuilder	newBuilder() Create a new rating builder.

Methods inherited from class org.lenskit.data.entities.AbstractBeanEntity

getAttributeNames, getAttributes, getBoolean, getDouble, getInteger, getLong, getTypedAttributeNames, hasAttribute, hasAttribute, makeLayout, maybeGet, maybeGet

Methods inherited from class org.lenskit.data.entities.AbstractEntity

asMap, describeTo, get, get, getId, getType, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ENTITY_TYPE

public static final EntityType ENTITY_TYPE

ATTRIBUTES

public static final AttributeSet ATTRIBUTES

Method Detail

create

@Deprecated
public static Rating create(long uid,
                                        long iid,
                                        double rating)

Deprecated. Use EntityFactory.rating(long, long, double)

Create a new rating object with no timestamp.

Parameters:

uid - The user ID.

iid - The item ID.

rating - The rating value. Cannot be NaN.

Returns:

The new rating object.

See Also:

create(long, long, double, long)

create

@Deprecated
public static Rating create(long uid,
                                        long iid,
                                        double rating,
                                        long ts)

Deprecated. Use EntityFactory.rating(long, long, double, long)

Create a new rating object.

Parameters:

uid - The user ID.

iid - The item ID.

rating - The rating value. Cannot be NaN.

ts - The timestamp.

Returns:

The new rating object.

Throws:

java.lang.IllegalArgumentException - if rating is NaN.

newBuilder

public static RatingBuilder newBuilder()

Create a new rating builder.

Returns:

A new rating builder.

getUserId

@EntityAttribute(value="user")
public long getUserId()

Description copied from interface: Preference

Get the ID of the user whose preference this is.

Specified by:

getUserId in interface Preference

Returns:

The user ID.

getItemId

@EntityAttribute(value="item")
public long getItemId()

Description copied from interface: Preference

Get the ID of the item the preference is for.

Specified by:

getItemId in interface Preference

Returns:

The item ID.

getTimestamp

public long getTimestamp()

getValue

@EntityAttribute(value="rating")
public double getValue()

Get the rating value.

Specified by:

getValue in interface Preference

Returns:

double The rating value, or Double.NaN if the rating has no value.

copyBuilder

public RatingBuilder copyBuilder()

Create a new rating builder that will build a copy of this rating.

Returns:

A rating builder initialized with the contents of this rating.

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class AbstractEntity