parity.personalNewAccountFromWallet(...) returns NullPointerException with valid arguments

[beatrizsanchez]

Goal
I am trying to create a wallet on a client that is not running a node and then create a new account on the blockchain from that wallet through parity.personalNewAccountFromWallet(...).

Context
I can't find a way to access the credentials of an account created with parity.personalNewAccount(...) because WalletUtils.loadCredentials(...) will try loading the wallet from the remote client instead of the machine running the node. Therefore, I thought that the best way to create an account would be through the wallet.

What I am doing
I am running personalNewAccountFromWallet(...) with non-null valid arguments (WalletFile and Password) yet the method throws a NullPointerException. My code is as follows:

ECKeyPair ecKeyPair = Keys.createEcKeyPair();
Credentials credentials = Credentials.create(ecKeyPair);
WalletFile wallet = Wallet.createLight(password, ecKeyPair);
ObjectMapper objectMapper = ObjectMapperFactory.getObjectMapper();
String output =  walletDir + "/" + wallet.getAddress() + ".json";
objectMapper.writeValue(new File(output), wallet);
parity.personalNewAccountFromWallet(wallet, password).send();

I need to know if this is an implementation error on my side or from the tools (web3j or ethereum)

Whether it was my mistake or not, I think the error message could be more helpful..

[conor10]

Hi @beatrizsanchez, it appears that the parity API has changed - this call is now named slightly differently from when I originally implemented it, which is why it is failing.

https://github.com/paritytech/parity/wiki/JSONRPC-parity_accounts-module#parity_newaccountfromwallet

You're welcome to submit a PR to rename this.

In terms of your code, the following is a more straight forwards implementation:

String password = "password";
String destDir = "/Users/Conor/tmp";
ObjectMapper objectMapper = ObjectMapperFactory.getObjectMapper();

String walletFileName = WalletUtils.generateNewWalletFile(password, new File(destDir), false);
WalletFile walletFile = objectMapper.readValue(
        new File(destDir + File.separator + walletFileName), WalletFile.class);

NewAccountIdentifier newAccountIdentifier = parity.personalNewAccountFromWallet(
        walletFile, password).send();

I've raised #74 for the main piece of work that needs to be done to support all of the revised calls properly.

[conor10]

Fixed by #147.