How to use web3j in java to get the Ethereum new PAIRS event, and get the contract address of the new PAIRS

Question

How to use web3j in java to get the Ethereum new PAIRS event, and get the contract address of the new PAIRS。.

Here is part of my code, I don't know what to do

private static void listenForNewContracts(Web3j web3j) {
    try {
        web3j.transactionFlowable().subscribe(tx -> {
            Transaction transaction = web3j.ethGetTransactionByHash(tx.getHash()).send().getTransaction().get();
        }, Throwable::printStackTrace);
    } catch (Exception e) {
        e.printStackTrace();
    }
}