CacheableOptional (Core XMPP Server 4.8.2 API)

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

All Methods Static Methods Instance Methods Concrete Methods
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 Detail
  - 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