Java - text not showing when for() is executing : Below is the example demonstrates that the text ("A","B","C" and "testing in progress...") for each Label and TextArea will not showing when a for() is executing. It will shows simultaneously once for() is finished....!

Any solution to overcome this 'phenomenon'? 


Example:-

public class Test1Controller 
{

    @FXML
    private Label l1;
    @FXML
    private Label l2;
    @FXML
    private Label l3;
    @FXML
    private TextArea info;
    @FXML
    private Button B1;

    
    @FXML
    void B1_runing(ActionEvent event) 
    {
 	
    	l1.setText("A");
    	l2.setText("B");
    	l3.setText("C");
    	info.appendText("testing in progress...\n");    	   	
    	B1.setDisable(true);
    	
    	for( int i=0; i<800; i++ )
    	{
    		for( int x=0; x<10000000; x++ );
    	}
    	
    	info.appendText("end...\n");
    }
    
}   