com.bea.wli.config.component.impl

Class LazyValue<K,V>

java.lang.Object

com.bea.wli.config.component.impl.LazyValue<K,V>

Direct Known Subclasses:

LazyValueCache.DataCacheEntry

public abstract class LazyValue<K,V>
extends java.lang.Object

A container whose value is computed lazily on access. The computation result is referenced via either a hard, soft or weak reference. This class is best used as a value in a hash map.

Field Summary

Fields

Modifier and Type	Field and Description
static int	HARD
static int	SOFT
static int	WEAK

Constructor Summary

Constructors

Constructor and Description
LazyValue(int type, K key)
LazyValue(int type, K key, V value)

Method Summary

Modifier and Type	Method and Description
void	clear() Clears the soft or weak referenes
protected abstract V	evaluate()
K	getKey() Returns the key;
V	getValue() returns the value, compute it if necessary
V	peekValue() Returns the value if it is currenrly available.

Methods inherited from class java.lang.Object

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

Field Detail

HARD

public static final int HARD

See Also:

Constant Field Values

SOFT

public static final int SOFT

See Also:

Constant Field Values

WEAK

public static final int WEAK

See Also:

Constant Field Values

Constructor Detail

LazyValue

public LazyValue(int type,
                 K key)

LazyValue

public LazyValue(int type,
                 K key,
                 V value)

Method Detail

getKey

public final K getKey()

Returns the key;

clear

public final void clear()

Clears the soft or weak referenes

peekValue

public final V peekValue()

Returns the value if it is currenrly available. 2 sequential calls to this method could return differrnet values if GC occured in between.

getValue

public final V getValue()

returns the value, compute it if necessary

evaluate

protected abstract V evaluate()