Groovy compiler does not accept java 8 Lambdas

Yeah, the Groovy parser does not accept Java 8 Lambdas (not closures).

You can use a closure in place of it (assuming you’re on Groovy 2.3.*)

ie:

Person.findAll().stream().filter( { e -> e.age > 20 } )

edit:

Groovy 3.0+ will accept lambda format