uk.org.lidalia.lang

Class LazyValue<T>

java.lang.Object

uk.org.lidalia.lang.LazyValue<T>

Type Parameters:

T - the type of the value wrapped by this class

All Implemented Interfaces:

Callable<T>

public class LazyValue<T>
extends Object
implements Callable<T>

Wraps and exposes the lazily evaluated result of an expression passed as a Callable to the constructor.

Constructor Summary

Constructors

Constructor and Description
LazyValue(Callable<T> supplier)

Method Summary

Methods

Modifier and Type	Method and Description
T	call()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

LazyValue

public LazyValue(Callable<T> supplier)

Parameters:

supplier - contains the expression (as a Callable) that will create the result; this will be evaluated once and only once

Method Detail

call

public T call()

Specified by:

call in interface Callable<T>

Returns:

the result of the expression passed to the constructor; this is evaluated the first time this method is called, subsequent calls return the same result without re-evaluating it. Concurrent calls block until the first execution is complete.

Throws:

Exception - thrown by the original caller, unwrapped

toString

public String toString()

Overrides:

toString in class Object