JEP 323 Where is @Notnull in java-11

Question

I started Java 11 yesterday, I downloaded the JDK , made to Environment variables of PC(windows), created a new project and set up the JDK and JRE to point to the Java 11.

I even checked my Env Variables again by echo %JAVA_HOME% in cmd , it is fine.

Every things seems ok but my compiler is not recognizing @Notnull var , can someone help!

Basic program i am trying to execute:

                 list.stream()
                .map((@Notnull var s) -> s.toLowerCase())
                .collect(Collectors.toList());

Error is:

Error:(13, 24) java: cannot find symbol
symbol:   class Notnull
location: class Main

Have even changed the language level in Project structure by Ctrl+Shift+Alt+S to X-Experimental features , but nothing helps.

Tried checking import java.lang.*; and found that @Notnull is not there too.

Answer 1

JEP 323 provides the syntax to use annotations on lambda parameters.

There is no class named Notnull , or NotNull , or NonNull . The use of “ @Nonnull ” in JEP 323's text is just an example of how a theoretical annotation might be used.