Get refecence ton contining instance from anonymous class

Question

I have the following code:

class Foo 
{
    public Foo()
    {
        new ActionListener()
        {
            public void actionPerformed( ActionEvent e )
            {
                // how can I use a reference to Foo here
            }
        }
    }
}

I can use member variables of the current Foo instance from inside actionPerformed. I I use this I get the instance of ActionListener. But how can I get a reference to the current Foo instance itself?

http://stackoverflow.com/questions/1816458/getting-hold-of-the-outer-class-object-from-the-inner-class-object — Reimeus, Nov 30 '15 at 10:26

score 3 · Accepted Answer · answered Nov 30 '15 at 10:23

3

You can access the Foo instance by using Foo.this:

class Foo
{
  public Foo()
  {
    new ActionListener()
    {
      @Override
      public void actionPerformed(final ActionEvent e)
      {
        Foo thisFoo = Foo.this;
      }
    };
  }
}

answered Nov 30 '15 at 10:23

neomega

712
5
19

score 3 · Answer 2 · answered Nov 30 '15 at 10:23

with Classname.this you get the instance in your ActionListener:

class Foo 
{
  void doSomething(){
      System.out.println("do something");
  };

    public Foo()
    {
        new ActionListener()
        {
            public void actionPerformed( ActionEvent e )
            {
                Foo.this.doSomething();
            }
        }
    };
}

score 1 · Answer 3 · answered Nov 30 '15 at 10:25

You can create a local variable containing "this" and use it in the Anonymous inner class:

final Foo thisFoo = this;
ActionListener al = new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent arg0) {

        // use thisFoo in here
    }
};

Get refecence ton contining instance from anonymous class

3 Answers3