com.googlecode.objectify.util

Class ResultCache<T>

java.lang.Object

com.googlecode.objectify.util.ResultCache<T>

All Implemented Interfaces:

Result<T>, Serializable

Direct Known Subclasses:

IteratorFirstResult, ResultTranslator

public abstract class ResultCache<T>
extends Object
implements Result<T>, Serializable

Caches a result value so it is only executed once

Author:

Jeff Schnitzer

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ResultCache()

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	isExecuted()
T	now() Waits if necessary for the computation to complete, and then retrieves its result.
protected abstract T	nowUncached()
protected void	postExecuteHook() Executed once after the cached value is assigned.
String	toString() We can get away with this because the subclass almost always provides concrete types
protected Object	writeReplace() When this serializes, write out a simple version that doesn't hold complicated links to internal structures.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResultCache

public ResultCache()

Method Detail

nowUncached

protected abstract T nowUncached()

isExecuted

protected boolean isExecuted()

now

public final T now()

Description copied from interface: Result

Waits if necessary for the computation to complete, and then retrieves its result. If the computation produced an exception, it will be thrown here.

Specified by:

now in interface Result<T>

Returns:

the computed result

postExecuteHook

protected void postExecuteHook()

Executed once after the cached value is assigned.

writeReplace

protected Object writeReplace()
                       throws ObjectStreamException

When this serializes, write out a simple version that doesn't hold complicated links to internal structures. This is safe as long as nobody ever tries to cast to ResultCache directly, which should never happen.

Throws:

ObjectStreamException

toString

public String toString()

We can get away with this because the subclass almost always provides concrete types

Overrides:

toString in class Object