org.springframework.data.mapping

Class Alias

java.lang.Object

org.springframework.data.mapping.Alias

public final class Alias
extends Object

A container object which may or may not contain a type alias value. If a value is present, isPresent() will return true and getValue() will return the value.

Additional methods that depend on the presence or absence of a contained value are provided, such as hasValue(Object) or isPresent()

Aliases are immutable once created.

Author:

Oliver Gierke, Christoph Strobl, Mark Paluch

Field Summary

Fields

Modifier and Type	Field and Description
static Alias	NONE Common instance for empty().

Method Summary

Modifier and Type	Method and Description
static Alias	empty() Returns an empty Alias instance.
boolean	equals(Object o)
Object	getValue()
int	hashCode()
boolean	hasSamePresentValueAs(Alias other) Returns whether the the current alias is present and has the same value as the given Alias.
boolean	hasValue(Object that) Checks whether this Alias contains the value that.
boolean	isPresent()
boolean	isPresentButDifferent(Alias other) Checks whether this Alias has a value but is different from the other value.
<T> T	mapTyped(Class<T> type) Return the value typed to type if the value is present and assignable to type.
static Alias	of(Object alias) Create an Alias given the alias object.
static Alias	ofNullable(Object alias) Create an Alias from a possibly present alias object.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

NONE

public static final Alias NONE

Common instance for empty().

Method Detail

of

public static Alias of(Object alias)

Create an Alias given the alias object.

Parameters:

alias - must not be null.

Returns:

the Alias for alias.

ofNullable

public static Alias ofNullable(@Nullable
                               Object alias)

Create an Alias from a possibly present alias object. Using a null alias will return empty().

Parameters:

alias - may be null.

Returns:

the Alias for alias or empty() if the given alias was null.

empty

public static Alias empty()

Returns an empty Alias instance. No value is present for this Alias.

Returns:

an empty Alias.

isPresentButDifferent

public boolean isPresentButDifferent(Alias other)

Checks whether this Alias has a value but is different from the other value.

Parameters:

other - must not be null.

Returns:

true if this value is present but different from the other value.

hasValue

public boolean hasValue(Object that)

Checks whether this Alias contains the value that.

Parameters:

that - the other value, may be null.

Returns:

true if this alias has a value and it equals to that.

hasSamePresentValueAs

public boolean hasSamePresentValueAs(Alias other)

Returns whether the the current alias is present and has the same value as the given Alias.

Parameters:

other - the other Alias

Returns:

true if there's an alias value present and its equal to the one in the given Alias.

isPresent

public boolean isPresent()

Returns:

true if this Alias contains a value.

mapTyped

@Nullable
public <T> T mapTyped(Class<T> type)

Return the value typed to type if the value is present and assignable to type.

Parameters:

type - must not be null.

Returns:

toString

public String toString()

Overrides:

toString in class Object

getValue

public Object getValue()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object