Javadoc in 9 seems to treat all interfaces with only one method as functional interfaces

Daniel Fuchs daniel.fuchs at
Mon Mar 17 16:28:01 UTC 2014

Hi guys,

While playing with JDK 9 javadoc command I noticed that it
seems to treat all single method interfaces as if they were
functional interfaces - even though they don't have the
@FunctionalInterface annotation.

For instance - I did 'make docs' - and I'm seeing this text
in the javadoc for 'java.awt.event.ActionListener':

Functional Interface:
     This is a functional interface and can therefore be used as the 
assignment target for a lambda expression or method reference.

Is that a known issue, or a new regression, or did I miss something?

best regards,

-- daniel

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