Class DefaultIfNullFunction

  • All Implemented Interfaces:
    Expression, Function

    public class DefaultIfNullFunction
    extends FunctionImpl
    Function that takes an input value, and a default value. If the input value is null (or evaluating it raises an exception), returns the default value; otherwise, returns the input value.
    • Constructor Detail

      • DefaultIfNullFunction

        public DefaultIfNullFunction()
    • Method Detail

      • evaluate

        public Object evaluate​(Object object)
        Description copied from class: FunctionImpl
        Default implementation simply returns the fallbackValue.

        Please override this method to produce a value based on the provided arguments.

        Specified by:
        evaluate in interface Expression
        Overrides:
        evaluate in class FunctionImpl
        Parameters:
        object - Object being evaluated; often a Feature
        Returns:
        value for the provided object
      • evaluate

        public <T> T evaluate​(Object object,
                              Class<T> context)
        Description copied from class: ExpressionAbstract
        Default implementation delegates handling of context conversion to Converters utility class.

        Subclasses are expected to make use of the Converters utility class (as the easiest way to provide value morphing in conformance with the Filter specification).

        Specified by:
        evaluate in interface Expression
        Overrides:
        evaluate in class ExpressionAbstract
        Type Parameters:
        T - The type of the returned object.
        Parameters:
        object - The object to evaluate the expression against.
        context - The type of the resulting value of the expression.
        Returns:
        Evaluates the given expression based on the content of the given object an an instance of context.