Improve the site ( Self-writing, java)

1) This is to set up sorting, so that when you click on the price - sorted, quantity - sorted, etc., 2 ) On the site there is a system of the type of guarantor (The buyer pays - the money hangs on the site - after which the seller fulfills the terms of the order - after which the buyer confirms) Here after the purchase, the money is recorded in a frozen state - it must be removed, just make it so that after the purchase nothing is recorded there but recorded only after confirming the purchase, remove the frozen state. 3) The seller in the transaction displays the price without deducting the commission, that is, as in the video, 100 p cost the goods 90 p received the seller, the balance recorded everything correctly, but in the history of transactions and in the history of finance it is written 100 p, it is necessary that it is displayed there already with the deduction of the commission.