Flow variables all null in java Snippet custom constructor

I need to create a custom constructor in a Java Snippet:

public JSnippet () {
//... use a flow variable to initialize an object
}

I want to use a flow variabel in the contructor however they are always still set to null at this point. How to I get the value?

Yes, you are right, if I initialize them before, they are null. I will add this into our bug tracking system.

What do you want to achieve, maybe we find a workaround?

Sadly I don't remember what my goal was. 2 months passed since.