How to create accounts and also retrieving the ether balance with web3j in a java file?

Question

I do not see anything in creating accounts and retrieving ether balance in web3j's documentation, I wonder if it is possible.

Answer 1

The "ethGetBalance" method will return the balance of any given account. Pls see example below:

// connect to node
Web3j web3 = Web3j.build(new HttpService());  // defaults to http://localhost:8545/

// send asynchronous requests to get balance
EthGetBalance ethGetBalance = web3
  .ethGetBalance("0xAccountAddress", DefaultBlockParameterName.LATEST)
  .sendAsync()
  .get();

BigInteger wei = ethGetBalance.getBalance();

Answer 2

You can use CURL command or use request module inside your code to call create account API -

CURL command for your reference:

curl -X POST --data '{"jsonrpc":"2.0","method":"personal_newAccount","params":["pass"],"id":74}' http://localhost:8545

Also, you must run the geth node with the "personal" api enabled to make this method available:

geth --rpc --rpcapi "personal,eth,web3"

---

To check account balance using web3js, use following command -

web3.eth.getBalance('account address hash in quotes')

Hope this helps.

Answer 3

This is how you do it kotlin web3j. I'm using Goerli infura

val web3j = Web3j.build(HttpService("https://goerli.infura.io/v3/YOUR_GOERLI_INFURA_KEY"))
var mBalance: EthGetBalance =
            web3j.ethGetBalance(walletAddress, DefaultBlockParameterName.LATEST).sendAsync()
                .get()
val unScaledBalance = mBalance.balance
val scaledBalance = BigDecimal(unScaledBalance).divide(
            BigDecimal(1000000000000000000L),
            18,
            RoundingMode.HALF_UP
        )
    Log.d(TAG, "checkAddressBalance: ScaledBalance: $scaledBalance")