创建类的不同方法？

Question

I've been practicing making GUI in netbeans and came across this auto generated code

  saveButton.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mousePressed(java.awt.event.MouseEvent evt) {
                saveButtonMousePressed(evt);
            }

I'm just confused in the argument "new java.awt.event.MouseAdapter()". I know that when we use the "new" keyword we make an object of that class. But after that "new" statement it declared a method so my perception was that "an object with a method? I know we create object so that we can use methods not create a method within them".

After researching and reading about Inner Classes, I now have a different perspective.

Would that be possible to create a class in a argument with the "new" statement? if true then that code didn't created a object, but instead created a class.

If my conclusion would be right there are 2 ways (I know so far) to create classes in java.

1. by using,

    public clas Sample() { //insert methods here } 

2. and by using,

    public void getSomething(new Sample() { //insert method here }) 

Did I get this one right? I'm just a beginner in java(Self Study).

Answer 1

It's not a different way to create a class , actually you define it in the same way you would with any other class but you don't name it, it is just a specialized MouseAdapter .

What actually happens is that you define a specialized version of mousePressed without the need to associate it to a named subclass of MouseAdapter . It's like defining and using the class in the same point. You define a specific class with specific behavior and instantiate it.

Indeed that's called an anonymous class . This has nothing in common with an inner class , which is a class that is defined inside another class (so they are nested).