org.codehaus.plexus.interpolation
Class SimpleRecursionInterceptor

java.lang.Object
  org.codehaus.plexus.interpolation.SimpleRecursionInterceptor

All Implemented Interfaces:

RecursionInterceptor

public class SimpleRecursionInterceptor
extends java.lang.Object
implements RecursionInterceptor

Simplest implementation of a RecursionInterceptor, which checks whether the existing interpolation effort is already attempting to resolve an exact expression, but has not finished. This will not catch synonym expressions, as are found in Maven (${project.build.directory}, ${pom.build.directory}, and ${build.directory} are synonyms).

Version:

$Id: SimpleRecursionInterceptor.java 7529 2008-07-20 20:24:21Z olamy $

Author:

jdcasey

Constructor Summary

SimpleRecursionInterceptor()

Method Summary

void	expressionResolutionFinished(java.lang.String expression) Signal to the interceptor that the all efforts to resolve the given expression have completed - whether successfully or not is irrelevant - and that the expression should not be tracked for recursion any longer.
void	expressionResolutionStarted(java.lang.String expression) Log the intention to start resolving the given expression.
java.util.List	getExpressionCycle(java.lang.String expression) When an expression is determined to be a recursive reference, this method returns the sublist of tracked expressions that participate in this cycle.
boolean	hasRecursiveExpression(java.lang.String expression) Check whether the current expression is already present in the in-process stack.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleRecursionInterceptor

public SimpleRecursionInterceptor()

Method Detail

expressionResolutionFinished

public void expressionResolutionFinished(java.lang.String expression)

Signal to the interceptor that the all efforts to resolve the given expression have completed - whether successfully or not is irrelevant - and that the expression should not be tracked for recursion any longer.

Specified by:

expressionResolutionFinished in interface RecursionInterceptor

Parameters:

expression - The expression to stop tracking.

expressionResolutionStarted

public void expressionResolutionStarted(java.lang.String expression)

Log the intention to start resolving the given expression. This signals the interceptor to start tracking that expression to make sure it doesn't come up again until after it has been resolved (or, fails to resolve).

Specified by:

expressionResolutionStarted in interface RecursionInterceptor

Parameters:

expression - The expression to be resolved.

hasRecursiveExpression

public boolean hasRecursiveExpression(java.lang.String expression)

Check whether the current expression is already present in the in-process stack.

Specified by:

hasRecursiveExpression in interface RecursionInterceptor

Parameters:

expression - The value to check for expression cycles.

Returns:

True if the value contains tracked expressions; false otherwise.

getExpressionCycle

public java.util.List getExpressionCycle(java.lang.String expression)

When an expression is determined to be a recursive reference, this method returns the sublist of tracked expressions that participate in this cycle. Otherwise, if the expression isn't present in the in-process stack, return Collections.EMPTY_LIST.

Specified by:

getExpressionCycle in interface RecursionInterceptor

Returns:

The list of expressions that participate in the cycle caused by the given expression.