How To Associate Two Classes

I have two classes.

First and Second.

In First class I want to use methods from Second class. So:

Java Code:

Second s = new Second();
s.secondMethod(); mh_sh_highlight_all('java');

Second thing I want to do is use JTextArea from First class in Second class.

So since it gives me error, I extended First class with Second:

Java Code: public class Second extends First { mh_sh_highlight_all('java');

It look like it should work, no errors etc. Also both things are working separately. But since I used both at once...

Java Code:

Exception in thread "AWT-EventQueue-0" java.lang.StackOverflowError
at package.Second.<init>(Second.java:7)
at package.First.<init>(First.java:17) mh_sh_highlight_all('java');

I can move what I need to First class, and it will work fine, but I want to make this in two classes. But I really don't understand extends, I just use them if there is need for them. So I don't know how to handle this problem.

I also tried to extends Second just like First:

Java Code: public class Second extends JPanel implements ActionListener { mh_sh_highlight_all('java');

Instead of extending First, but it can not be done, since ActionListener is in First...

Well. Also addActionListener can maybe solve my problem?

I'm using:

Java Code: xx.addActionListener(this); mh_sh_highlight_all('java');

Maybe I can use something instead of this? But what?