Connection conn = null;
Statement stmt = null;
PreparedStatement pstmt = null;
ResultSet rs = null;


public ArrayList<Coffee> getAllCoffees()
{
    try
    {
        conn = ConnectionPool.getPool().getConnection();
        String sql = "SELECT * FROM coffees";
        stmt = conn.createStatement();
        rs = stmt.executeQuery(sql);
        ArrayList<Coffee> coffeeList = new ArrayList<Coffee>();
        Coffee coffee = null;
        while(rs.next())
        {
            coffee = new Coffee();
            coffee.setCof_name(rs.getString("cof_name"));
            coffee.setSup_id(rs.getInt("sup_id"));
            coffee.setPrice(rs.getDouble("price"));
            coffee.setSales(rs.getDouble("sales"));
            coffee.setTotal(rs.getDouble("total"));
            coffeeList.add(coffee);
        }
        return coffeeList;
    }
    catch(Exception ex)
    {
        ex.printStackTrace();
        throw new RuntimeException();
    }
    finally
    {
        try
        {
            if(rs != null)
            {
                rs.close();
            }
            if(stmt != null)
            {
                stmt.close();
            }
            if(conn != null)
            {
                ConnectionPool.getPool().releaseConnection(conn);
            }
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
            throw new RuntimeException(ex);
        }
    }
}

return null:

catch(Exception ex)
    {
        ex.printStackTrace();
        //throw new RuntimeException();

        return new ArrayList<Coffee>() ;

    }