is.codion.framework.domain.entity

Interface Key

public interface Key

Represents a unique attribute value combination for a given entity.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Key.Builder A builder for Key instances.

Method Summary

Modifier and Type	Method and Description
<T> Attribute<T>	attribute() Returns this keys attribute.
List<Attribute<?>>	attributes()
Key.Builder	copyBuilder() Creates a new Key.Builder instance, initialized with the values in this key.
EntityDefinition	definition()
<T> T	get() Returns the value of this key.
<T> T	get(Attribute<T> attribute)
<T> Optional<T>	getOptional() Returns the value of this key, wrapped in an Optional.
<T> Optional<T>	getOptional(Attribute<T> attribute)
boolean	isNotNull()
boolean	isNotNull(Attribute<?> attribute) Returns true if a non-null value is mapped to the given attribute.
boolean	isNull()
boolean	isNull(Attribute<?> attribute) Returns true if a null value is mapped to the given attribute or no mapping exists.
boolean	isPrimaryKey()
EntityType	type()

Method Detail

type

EntityType type()

Returns:

the entity type

definition

EntityDefinition definition()

Returns:

the entity definition

attributes

List<Attribute<?>> attributes()

Returns:

the attributes comprising this key

isPrimaryKey

boolean isPrimaryKey()

Returns:

true if this key represents a primary key for an entity, note that this is true for empty keys representing entities without a defined primary key

isNull

boolean isNull()

Returns:

true if this key contains no values or if it contains a null value for a non-nullable key attribute

isNotNull

boolean isNotNull()

Returns:

true if no non-nullable values are null

isNull

boolean isNull(Attribute<?> attribute)

Returns true if a null value is mapped to the given attribute or no mapping exists.

Parameters:

attribute - the attribute

Returns:

true if the value mapped to the given attribute is null or none exists

isNotNull

boolean isNotNull(Attribute<?> attribute)

Returns true if a non-null value is mapped to the given attribute.

Parameters:

attribute - the attribute

Returns:

true if a non-null value is mapped to the given attribute

attribute

<T> Attribute<T> attribute()

Returns this keys attribute. Note that this method throws an exception if this key is a composite key.

Type Parameters:

T - the attribute type

Returns:

the key attribute, useful for single attribute keys

Throws:

IllegalStateException - in case this is a composite key or if it contains no attributes

get

<T> T get()

Returns the value of this key. Note that this method throws an exception if this key is a composite key.

Type Parameters:

T - the value type

Returns:

the first value contained in this key, useful for single attribute keys

Throws:

IllegalStateException - in case this is a composite key or if it contains no values

getOptional

<T> Optional<T> getOptional()

Returns the value of this key, wrapped in an Optional. Note that this method throws an exception if this key is a composite key.

Type Parameters:

T - the value type

Returns:

the first value contained in this key, wrapped in an Optional, useful for single attribute keys

Throws:

IllegalStateException - in case this is a composite key

get

<T> T get(Attribute<T> attribute)

Type Parameters:

T - the value type

Parameters:

attribute - the attribute

Returns:

the value associated with the given attribute

getOptional

<T> Optional<T> getOptional(Attribute<T> attribute)

Type Parameters:

T - the value type

Parameters:

attribute - the attribute

Returns:

the value associated with the given attribute, wrapped in an Optional

copyBuilder

Key.Builder copyBuilder()

Creates a new Key.Builder instance, initialized with the values in this key.

Returns:

a new builder based on this key