Class SimpleRecursionInterceptor

  • All Implemented Interfaces:
    RecursionInterceptor

    public class SimpleRecursionInterceptor
    extends 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).
    Author:
    jdcasey
    • Constructor Detail

      • SimpleRecursionInterceptor

        public SimpleRecursionInterceptor()
    • Method Detail

      • expressionResolutionFinished

        public void expressionResolutionFinished​(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​(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​(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 List getExpressionCycle​(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
        Parameters:
        expression - the expression to start with.
        Returns:
        The list of expressions that participate in the cycle caused by the given expression.