i've seen this in exchanges wallets. so if u transfer some coins to the address which is use for deposits even after it change, it would still link to your wallet. so i want to make a gateway for my application. so its like 7 public ETH address would route all to a main wallet. is it possible?
This shouldn't be possible with the basic transfer flow on Ethereum. Still, you may be able to achieve it in one of the following ways:
Use smart contracts instead of EOAs [custom contract logic]
Custom contract with some redirect method. Users transfer to these contracts. Once in a while, when gas is cheap, you (the owner) can redirect these funds towards a treasury wallet. For ETH, I think you can also implement special handlers for the deposits, but not for ERC20s.
Pre-approved wallets [custom contract logic]
There's still the need for you to pay gas for "harvesting" but you could pre-approve a treasury contract to spend ERC20s from these 7 addresses. Once in a while, you'd redirect the assets into that contract, where you as the owner would be able to finally manage the assets.
Use a custom backend [pure web3]
Use a custom backend that has access (private keys) to those wallets and once in a while run a script that collects funds.