org.lenskit.data.entities

Class AbstractEntity

java.lang.Object

org.lenskit.data.entities.AbstractEntity

All Implemented Interfaces:

Describable, Entity

Direct Known Subclasses:

Rating

public abstract class AbstractEntity
extends Object
implements Entity, Describable

Base class to make it easier to implement entities.

Field Summary

Fields

Modifier and Type	Field and Description
protected long	id
protected EntityType	type

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractEntity(EntityType t, long eid)

Method Summary

Modifier and Type	Method and Description
Map<String,Object>	asMap() View this entity as a map.
void	describeTo(DescriptionWriter writer) Write this class’s description to a sink.
boolean	equals(Object obj)
Object	get(String attr) Get the value of an attribute by name.
<T> T	get(TypedName<T> name) Get the value of an attribute.
Set<String>	getAttributeNames() Get the names of the attributes in this entity.
Collection<Attribute<?>>	getAttributes() Get the attribute-value pairs.
boolean	getBoolean(TypedName<Boolean> name) Get the value of a attr that contains a boolean.
double	getDouble(TypedName<Double> name) Get the value of a attr that contains a double.
long	getId() Get the identifier of this entity.
int	getInteger(TypedName<Integer> name) Get the value of a attr that contains a int.
long	getLong(TypedName<Long> name) Get the value of a attribute that contains a long.
EntityType	getType() Get the type of this entity.
boolean	hasAttribute(TypedName<?> name) Check if the entity has a attribute.
int	hashCode()
<T> T	maybeGet(TypedName<T> name) Get the value of a possibly-missing attribute.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.lenskit.data.entities.Entity

getTypedAttributeNames, hasAttribute, maybeGet

Field Detail

type

protected final EntityType type

id

protected final long id

Constructor Detail

AbstractEntity

protected AbstractEntity(EntityType t,
                         long eid)

Method Detail

getId

public long getId()

Description copied from interface: Entity

Get the identifier of this entity.

Specified by:

getId in interface Entity

Returns:

The entity identifier.

getType

public EntityType getType()

Description copied from interface: Entity

Get the type of this entity.

Specified by:

getType in interface Entity

Returns:

The entity’s type.

hasAttribute

public boolean hasAttribute(TypedName<?> name)

Check if the entity has a attribute.

This implementation delegates to Entity.hasAttribute(String)

Specified by:

hasAttribute in interface Entity

Parameters:

name - The attribute name to look for.

Returns:

true if the entity contains attribute and the value is of the associated type. that the data is of a compatible type.

getAttributeNames

public Set<String> getAttributeNames()

Get the names of the attributes in this entity.

Delegates to Entity.getTypedAttributeNames() and extracts the names.

Specified by:

getAttributeNames in interface Entity

getAttributes

public Collection<Attribute<?>> getAttributes()

Get the attribute-value pairs.

Delegates to Entity.getTypedAttributeNames() and extracts the names.

Specified by:

getAttributes in interface Entity

asMap

public Map<String,Object> asMap()

Description copied from interface: Entity

View this entity as a map.

Specified by:

asMap in interface Entity

Returns:

A map reflecting the entity’s data.

get

@Nonnull
public <T> T get(TypedName<T> name)

Get the value of an attribute.

This implementation delegates to maybeGet(TypedName).

Specified by:

get in interface Entity

Parameters:

name - The attribute name.

Returns:

The attribute’s value.

get

@Nonnull
public Object get(String attr)

Get the value of an attribute by name.

This implementation delegates to Entity.maybeGet(String).

Specified by:

get in interface Entity

Parameters:

attr - The attribute name.

Returns:

The attribute value.

getLong

public long getLong(TypedName<Long> name)

Get the value of a attribute that contains a long.

This implementation delegates to get(TypedName).

Specified by:

getLong in interface Entity

Parameters:

name - The attribute name.

Returns:

The attribute’s value.

getDouble

public double getDouble(TypedName<Double> name)

Get the value of a attr that contains a double.

This implementation delegates to get(TypedName).

Specified by:

getDouble in interface Entity

Parameters:

name - The attribute name.

Returns:

The attribute’s value.

getInteger

public int getInteger(TypedName<Integer> name)

Get the value of a attr that contains a int.

This implementation delegates to get(TypedName).

Specified by:

getInteger in interface Entity

Parameters:

name - The attribute name.

Returns:

The attribute’s value.

getBoolean

public boolean getBoolean(TypedName<Boolean> name)

Get the value of a attr that contains a boolean.

This implementation delegates to get(TypedName).

Specified by:

getBoolean in interface Entity

Parameters:

name - The attribute name.

Returns:

The attribute’s value.

maybeGet

@Nullable
public <T> T maybeGet(TypedName<T> name)

Get the value of a possibly-missing attribute.

This implementation delegates to Entity.maybeGet(String) and checks the type.

Specified by:

maybeGet in interface Entity

Parameters:

name - The attribute name.

Returns:

The attribute’s value, or null if it is not present.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

describeTo

public void describeTo(DescriptionWriter writer)

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:

writer - The description writer to use.