Java - 这些是哪些类型的类； 哪个是匿名内部class？

Question

I've read several online articles which contradict each other. I thought this would be an example of an anonymous inner class:

button.addActionListener(new ActionListener() {
    public void actionPerfored(ActionEvent e) {
       // do something.
    }
});

However, I've also seen this described as an anonymous inner class:

ActionListener myListener = new ActionListener() { 
    public void actionPerformed(ActionEvent event) {
          // do something.
    }
};
button.addActionListener(myListener);

Which is which, and why? Thank you!

Answer 1

Both of them are. The second one is just assigned to a variable before being added as an action listener.

This is the same as the difference between

myList.add(new String("myString"));

and

String s = new String("myString");
myList.add(s);

it has nothing to do with anonymous classes.

Answer 2

Both are anonymous inner classes. In the second case you are storing a reference to the anonymous class just so that you can call some methods on it later.

Answer 3

Like Richante said, they both are.

Think about it, they both are unnamed and are defined inside another class.

Answer 4

Both are actually examples of Anonymous inner class. In First example, anonymous inner class is provided when passing an argument to addActionListener() method. In second example a reference to anonymous inner class is created.