Using lambda expressions for parameter expressions in JasperServer Studio

Requirement: 

While using lambda expressions while creating parameter expressions in JasperServer Studio we get the following error: 

"The target type of this expression must be a functional interface"

Recommendation:

Given the way report expressions are compiled, you need to explicitly cast the expression to the expected functional type. As in: 

<parameter name="Parameter1" class="java.util.function.Function">
<defaultValueExpression><![CDATA[(java.util.function.Function<String, String>) ((test) -> {return test + test;})]]></defaultValueExpression>
</parameter>