Code is always compiled without lambda parameter type

[Marcos Antonio]

Hello, everybody!
 
I have this piece of code in a class of mine:
 
addHierarchyListener(
    #{e ->
        if ((e.getChangeFlags() & HierarchyEvent.PARENT_CHANGED) != 0)
        {
            IJanela janela = UtilsIU.obterJanela(this);
            if (janela != null)
            {
                janela.getRootPane().setDefaultButton(_btnOk);
                btnCancelar.addActionListener(#{e -> janela.fechar()});
            }
            else if (btnCancelar.getActionListeners().length > 0)
            {
                btnCancelar.removeActionListener(btnCancelar.getActionListeners()[0]);
            }
        }
    }
);
 
The interesting thing that I noticed is that "ant" always compile the class
that has this fragment of code, even if I don't change it. It's like the
java file is always changed. Now if I make this little change (introducing
the type of the paramenter, HierarchyEvent), the code only compiles once,
after the change, as expected.
 
addHierarchyListener(
    #{HierarchyEvent e ->
        if ((e.getChangeFlags() & HierarchyEvent.PARENT_CHANGED) != 0)
        {
            IJanela janela = UtilsIU.obterJanela(this);
            if (janela != null)
            {
                janela.getRootPane().setDefaultButton(_btnOk);
                btnCancelar.addActionListener(#{e -> janela.fechar()});
            }
            else if (btnCancelar.getActionListeners().length > 0)
            {
                btnCancelar.removeActionListener(btnCancelar.getActionListeners()[0]);
            }
        }
    }
);
 
I think this is a problem, but I just don't know where.
 
Marcos