Vaadin Component as Spring bean

Solution 1:

If you use just @Component (or @SpringComponent) the class will be instantiated once for the application so, yes, you will get issues with multiple sessions sharing the resulting objects when you don't want them to. So you add @UIScope as well. That will ensure you get one instance of this class per session. You can store session data in the class (much as if you used Spring's @Session, but that requires you to use Spring's Dispatcher).

In a @UIScope class you can use @Autowired and @PostConstruct etc. I use it for extends of Windows and Layout etc. You need com.vaadin:vaadin-spring:1.0.0 on your classpath. Further info on vaadin-spring

Solution 2:

After increasing my knowledge I have some hypothesis.

Can we use Vaadin component as Spring bean? Why not. I tried this and it works. But...

But it cause also multiple listeners invocation - as I have class-instated Button object.

Spring creates the instance of the component by itself and put it somewhere. So I can't do anything in component constructor. Moreover such component should be cleaned and initialized before any use. Does it sound weird? I think yes. And it might cause a lot of problems - especially in multithread environment.

So I don't recommend making a Bean of any Vaadin components (for example Tab, Buttons...). Because they need to change their state depending on place of use.

But how to make available all Spring beans in object which is not maintained by Spring container? This isn't new question and there are at least two solutions:

1. Annotate such class with @Configurable and enable any weaving (compile or run time). This is explained for example here or here.

2. Directly use of AutowireCapableBeanFactory and autowiredBeanProperty() method. A little explanation can be find here and also on SO.