Editing Java syntax (section)

====Implementing an interface====
An interface is implemented by a class using the <code>implements</code> keyword. It is allowed to implement more than one interface, in which case they are written after <code>implements</code> keyword in a comma-separated list. A class implementing an interface must override all its methods, otherwise it must be declared as abstract.

<syntaxhighlight lang="java">
interface RequestListener {
    int requestReceived();
}

class ActionHandler implements ActionListener, RequestListener {
    public void actionSelected(int action) {
    }

    public int requestReceived() {
    }
}

//Calling method defined by interface
RequestListener listener = new ActionHandler(); /*ActionHandler can be
                                   represented as RequestListener...*/
listener.requestReceived(); /*...and thus is known to implement
                            requestReceived() method*/
</syntaxhighlight>