Java SE (Java Platform, Standard Edition)

Hi guys,

I was wondering how do I implement an aggregation in Java.
Here is the case:

Team has a 1 to N association to player.

First suggestion:

class Team{
      ArrayList<Player> players;
      ...
}

class Player{
...}

Second suggestion:

class Team{
      ArrayList<Player> players;
      ...
}

class Player{
    Team team
...}

My question is actually to know whether the objects of the class Player should know about the object Team that contains them.
I had a discussion about with a colleague of mine, and I really need to clear things up.
I personally tend for the first suggestion

Best regards.

Edmond