For the moment, I created an abstract class like this:

```
public abstract class MyClass {
    public final static String TAG;
    ...
}

```

But it gives me an error of not initializing a final variable. Then I tried to initialize it from a constructor, but it didn't work either (gives the same error plus another one of trying to set a value to a final variable), although many stackoverflow posts says that really works...

```
public abstract class MyClass {
    public final static String TAG;

    public MyClass(String u){
        this.TAG = u;
    }
}

```

It seems like final variables have to be assigned only when declaring the variable. Is this correct? How can I achieve this?