Metacat

Using getDBConenction rather than pass connection as parameter.

Using getDBConnection rather than pass connection as a parameter.

Using getDBConnection method rather than a parameter.

Change the prototype of method getUniqeID

Add DBConnectionPool object in servlet's init method and DBConnectionPool's release method in servlet's destory method.

Delete connection as a class field and make every method to check in and check out connection if it need.

Make a every method check in and check out DBConnection if this method need a connection.

In returnDBConnection method, a new parameter named serialNumber was added. It will compare to the checkOutSerialNumber in DBConnection.

Add a new attribute named checkOutSerialNumber, which to make sure when DBConnection would not be check in mutiple times.

Add the code to handle error in the respone for a update request.