I am implementing a listener to send notifications which implements JavaDelegate interface. I couldn’t autowire other service classes from this listener class.
How are you using this class? If it’s a Spring bean, it should be referenced with a delegateExpression and not through class (otherwise a new object gets created outside of the Spring container).
In order for @Autowired to work you’ll need to expose your class as a bean and use delegateExpression. When using class Flowable is not going to inject Spring dependencies in your class.