Package org.jivesoftware.util

Class CacheableOptional<T extends Serializable>

java.lang.Object

org.jivesoftware.util.CacheableOptional<T>

All Implemented Interfaces:

Serializable, Cacheable

public class CacheableOptional<T extends Serializable>
extends Object
implements Cacheable

Some times it is desirable to store in a Cache the absence of a value. Unfortunately, it's not possible to store a null value in a clustered cache because of the underlying hazelcast technology used for clustering. The obvious candidate would therefore be to store an Optional object in the cache instead - unfortunately an Optional is not serializable. This class therefore performs this functionality - an optional value that is cacheable.

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
static <T extends Serializable> CacheableOptional<T>	from(Optional<T> value)
T	get()
int	getCachedSize()	Returns the approximate size of the Object in bytes.
int	hashCode()
boolean	isAbsent()
boolean	isPresent()
static <T extends Serializable> CacheableOptional<T>	of(T value)
Optional<T>	toOptional()
String	toString()

Methods inherited from class java.lang.Object

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

Method Details

of

public static <T extends Serializable>
CacheableOptional<T> of(T value)

from

public static <T extends Serializable>
CacheableOptional<T> from(Optional<T> value)

get

public T get()

isPresent

public boolean isPresent()

isAbsent

public boolean isAbsent()

toOptional

public Optional<T> toOptional()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

getCachedSize

public int getCachedSize()
                  throws CannotCalculateSizeException

Description copied from interface: Cacheable

Returns the approximate size of the Object in bytes. The size should be considered to be a best estimate of how much memory the Object occupies and may be based on empirical trials or dynamic calculations.

Specified by:

getCachedSize in interface Cacheable

Returns:

the size of the Object in bytes.

Throws:

CannotCalculateSizeException - if the size cannot be calculated