Check whether a JPanel contains a JButton

I have added a button to a JPanel. I want to remove the button if the JPanel contains the button. Is ther开发者_如何学运维e any way to check whether the JPanel contains the button?

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If you have a reference to the JButton, call getParent(). If the parent is null, the button is not in the panel (or any container).

Alternately, do as @kleopatra suggested and call getComponents() on the JPanel instance and iterate the array looking for anything that is an instanceof JButton.

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Is checking necessary? If not, then just remove the JButton without checking. Nothing will happen if it is not contained by the JPanel.

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If you have a reference to the button:

List<Component> componentList = Arrays.asList(panel.getComponents());
if (!componentList.contains(button)) {
  panel.add(button);
}