Issue with Component Iteration and validation

Am having a method that check all JTextFields in a panel JPanel to see whether they are empty, am iterating through all the components in the container. in the container i have labels, text fields and combo boxes. So i can be able validate the first few JTextFields but when i encounter the first JComboBox<?> the validation stop and i don't seem to understand why. Below is the code :-

private boolean validateInputFields(JPanel container) {
    for (Component comp : container.getComponents()) {

        if (comp instanceof JTextField) {
            JTextField temp = (JTextField) comp;
            if (temp.getText().trim().equals("")) {
                changeComponentProperties(temp);
                return true;
            } else{
                temp.setBackground(Color.WHITE);
                temp.setForeground(Color.BLACK);
            }
        }
    }

    return false;
}

Any assistance will be highly appreciated.

Also note that this is invoked when a button (say save button) is clicked.

Alot of thanks for all who contributed, all the solutions you provided were valid and workable but in my situation i figure out the problem - The thing is some components were not visible in the screen and while iteration through the fetched components they were also not included, so i added a condition to check the component visibility state i.e comp.isVisible().