com.liferay.faces.util.lang
Class ThreadSafeAccessor<T,X>

java.lang.Object
  com.liferay.faces.util.lang.ThreadSafeAccessor<T,X>

Type Parameters:

T - The type that will be returned from the get(java.lang.Object) and computeValue(java.lang.Object) methods.

X - The type of argument that will be passed to the get(java.lang.Object) and computeValue(java.lang.Object) methods in order to initialize the ThreadSafeAccessor value.

public abstract class ThreadSafeAccessor<T,X>
extends Object

This class represents a lazily initialized, effectively immutable value. The value is initialized in a thread-safe way such that computeValue(java.lang.Object) is only called once by a single thread.

Author:

Kyle Stiemann

Constructor Summary

ThreadSafeAccessor()

Method Summary

protected abstract T	computeValue(X args) Returns the initial value of the ThreadSafeAccessor.
T	get(X arg) Returns the ThreadSafeAccessor value.

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadSafeAccessor

public ThreadSafeAccessor()

Method Detail

get

public final T get(X arg)

Returns the ThreadSafeAccessor value. The value is lazily initialized by the first thread that attempts to access it.

Parameters:

arg - The argument needed to initialize the ThreadSafeAccessor value.

computeValue

protected abstract T computeValue(X args)

Returns the initial value of the ThreadSafeAccessor. This method will only be called once by a single thread to obtain the initial value. Subclasses must override this method to provide the process necessary to compute the initial value of the ThreadSafeAccessor.

Parameters:

args - The argument needed to initialize the ThreadSafeAccessor value.