Rotate content of a JLabel in java

I have an application which consists of a JPanel , in that Panel I can add components of type JLabel which contains a text. I need that those jlabel can be rotated when the following button is pressed:

I have tried the following method to change its rotation but I can not get the same label repaint.

label = new JLabel("prueba") {
protected void paintComponent(Graphics grafico) {

Graphics2D graficoNuevo = (Graphics2D) grafico;

AffineTransform at = graficoNuevo.getTransform();

double X = getWidth() / 2.0;
double Y = getHeight() / 2.0;

at.rotate(Math.toRadians(90), X, Y);

graficoNuevo.setTransform(at);
super.paintComponent(graficoNuevo);
}
};

This code works to create a new label but what I really need is that the label previously created changes its rotation of the text it contains.