org.omnaest.utils.structure.element.cached
Class CachedElement<T>

java.lang.Object
  org.omnaest.utils.structure.element.cached.CachedElement<T>

Type Parameters:

T -

Direct Known Subclasses:

CachedElementTimed, SoftCachedElement, ThreadLocalCachedElement, WeakCachedElement

public class CachedElement<T>
extends Object

A CachedElement provides an abstract cache mechanism around a given value. The value is initially resolved once from a given CachedElement.ValueResolver.

Author:

Omnaest

Nested Class Summary

protected static interface	CachedElement.CachedValue<T> Used to store and retrieve the CachedElement.CachedValue
static interface	CachedElement.ValueResolver<T>
static class	CachedElement.ValueResolverSimple<T> Simple CachedElement.ValueResolver which returns the object initially given to the constructor.

Field Summary

protected CachedElement.CachedValue<T>	cachedValue
protected CachedElement.ValueResolver<T>	valueResolver

Constructor Summary

CachedElement(CachedElement.ValueResolver<T> valueResolver)

CachedElement(T value)

Method Summary

CachedElement<T>	clearCache() Clears the cached value, so the next call to getValue() will resolve the value once again from the underlying CachedElement.ValueResolver.
T	getValue() Returns the value from the cache or resolves it from the underlying CachedElement.ValueResolver if it is null.
T	getValueFromCacheOnly() Returns the cached value and does not resolve the value if the cached value is null.
CachedElement.ValueResolver<T>	getValueResolver()
boolean	hasValueResolved() Returns true, if the cache has resolved a value from the underlying CachedElement.ValueResolver instance.
protected CachedElement.CachedValue<T>	newCachedValue() Creates a new CachedElement.CachedValue instance.
void	setValueResolver(CachedElement.ValueResolver<T> valueResolver)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

cachedValue

protected CachedElement.CachedValue<T> cachedValue

valueResolver

protected CachedElement.ValueResolver<T> valueResolver

Constructor Detail

CachedElement

public CachedElement(CachedElement.ValueResolver<T> valueResolver)

Parameters:

valueResolver -

See Also:

CachedElement, CachedElement.ValueResolver

CachedElement

public CachedElement(T value)

Parameters:

value -

See Also:

CachedElement, CachedElement.ValueResolver, CachedElement.ValueResolverSimple

Method Detail

getValue

public T getValue()

Returns the value from the cache or resolves it from the underlying CachedElement.ValueResolver if it is null.

See Also:

getValueFromCacheOnly()

getValueFromCacheOnly

public T getValueFromCacheOnly()

Returns the cached value and does not resolve the value if the cached value is null.
Use getValue() for normal purposes.

Returns:

See Also:

getValue()

hasValueResolved

public boolean hasValueResolved()

Returns true, if the cache has resolved a value from the underlying CachedElement.ValueResolver instance.

Returns:

setValueResolver

public void setValueResolver(CachedElement.ValueResolver<T> valueResolver)

getValueResolver

public CachedElement.ValueResolver<T> getValueResolver()

clearCache

public CachedElement<T> clearCache()

Clears the cached value, so the next call to getValue() will resolve the value once again from the underlying CachedElement.ValueResolver.

Returns:

this

newCachedValue

protected CachedElement.CachedValue<T> newCachedValue()

Creates a new CachedElement.CachedValue instance. Override this to alternate the behavior of the CachedElement

Returns: