Cannot create default method in an interface

[malvee]

I am trying to generate the whole interface file at runtime and I need to add just 1 default method which calls other methods added to the CtClass before. The exception I get:
Exception in thread "main" javassist.CannotCompileException: [source error] syntax error near "**default Object** get" at javassist.CtNewMethod.make(CtNewMethod.java:79) at javassist.CtNewMethod.make(CtNewMethod.java:45) Caused by: compile error: syntax error near "**default Object get**" at javassist.compiler.Parser.parseClassType(Parser.java:984) at javassist.compiler.Parser.parseFormalType(Parser.java:192) at javassist.compiler.Parser.parseMember1(Parser.java:52) at javassist.compiler.Javac.compile(Javac.java:90) at javassist.CtNewMethod.make(CtNewMethod.java:74)
Whats the correct way to add default methods to an interface. The interface was made using makeInterface, and I am adding the default as .addMethod(CtNewMethod.make("default ....", interface))
I am using 3.12.1.GA from maven repo. Thanks.

[chibash]

Maybe you don't need "default" in the source...

[malvee]

I checked and I am using 3.20 now, so that does have Java8 support. Found another issue which seems to have been resolved but I am getting the exact same problem:
#104

[PastelBelem8]

I'm currently using version 3.22 and I cannot create default methods in interfaces at runtime.