Connection ==null and Connection is closed, difference

Hi experts,
I wonder what are the differences between "Connection==null" and "Connection is closed"?
I closed a connection on one JSP page after a bean has retrieved data. Then, on the same page I call another bean to connect to the database. Because the Connection object has been created earlier, therefore Connection is not NULL, but it is closed. So, the second bean has to initiate another connection(if I knew how to test the "closed" status)
Is it true that if the Connection is closed, then it should become null?
I think I must have make quite a few mistakes in above statement:). Please help. Thanks a lot.

connection.isClosed() will tell you if the connection object is closed or not. If it is closed, then the connection object can be dropped because you will not be able to create any new statements from that connection object. Just recreate another connection to use when this occurs.

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