org.picocontainer.defaults
Class ThreadLocalCyclicDependencyGuard

java.lang.Object
  java.lang.ThreadLocal
      org.picocontainer.defaults.ThreadLocalCyclicDependencyGuard

All Implemented Interfaces:

CyclicDependencyGuard

Direct Known Subclasses:

InstantiatingComponentAdapter.Guard

public abstract class ThreadLocalCyclicDependencyGuard

extends ThreadLocal

implements CyclicDependencyGuard

Abstract utility class to detect recursion cycles. Derive from this class and implement run(). The method will be called by observe(java.lang.Class). Select an appropriate guard for your scope. Any ObjectReference can be used as long as it is initialized with Boolean.FALSE.

Since:

1.1

Author:

Jörg Schaible

Constructor Summary

ThreadLocalCyclicDependencyGuard()

Method Summary

protected Object	initialValue()
Object	observe(Class stackFrame) Call the observing function.
abstract Object	run() Derive from this class and implement this function with the functionality to observe for a dependency cycle.

Methods inherited from class java.lang.ThreadLocal

get, set

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadLocalCyclicDependencyGuard

public ThreadLocalCyclicDependencyGuard()

Method Detail

initialValue

protected Object initialValue()

run

public abstract Object run()

Derive from this class and implement this function with the functionality to observe for a dependency cycle.

Specified by:

run in interface CyclicDependencyGuard

Returns:

a value, if the functionality result in an expression, otherwise just return null

observe

public final Object observe(Class stackFrame)

Call the observing function. The provided guard will hold the Boolean value. If the guard is already Boolean.TRUE a CyclicDependencyException will be thrown.

Specified by:

observe in interface CyclicDependencyGuard

Parameters:

stackFrame - the current stack frame

Returns:

the result of the run method