eth와erc20 코드 접속

웹 3j 기반
주소 만들기

    public static EthAddress createAddress() {
        try {
            String seed = UUID.randomUUID().toString();
            ECKeyPair ecKeyPair = Keys.createEcKeyPair();
            BigInteger privateKeyInDec = ecKeyPair.getPrivateKey();

            String sPrivatekeyInHex = privateKeyInDec.toString(16);

            WalletFile aWallet = Wallet.createLight(seed, ecKeyPair);
            String sAddress = aWallet.getAddress();

            EthAddress address = new EthAddress();
            address.setAddress("0x" + sAddress);
            address.setPrivateKey(sPrivatekeyInHex);
            return address;
        } catch (Throwable t) {
            logger.error("      ", t);
        }
        return null;
    }

 
조회erc20 잔액

    public static BigInteger balanceOfErc20(Web3j web3j, String contract, String address) {
        try {
            final String DATA_PREFIX = "0x70a08231000000000000000000000000";
            String value = web3j.ethCall(org.web3j.protocol.core.methods.request.Transaction.createEthCallTransaction(address,
                    contract, DATA_PREFIX + address.substring(2)), DefaultBlockParameterName.PENDING).send().getValue();
            if (StringUtils.isEmpty(value)) {
                return BigInteger.ZERO;
            }
            return new BigInteger(value.substring(2), 16);
        } catch (Throwable t) {
            logger.error(String.format("  ERC20   contract:%s address:%s", contract, address), t);
        }
        return BigInteger.ZERO;
    }

erc20 보내기

    public static String sendErc20(Web3j web3j, String contractAddress, String privateKey,
                                   String to, BigInteger value) {
        String from = getAddressByPrivateKey(privateKey);
        logger.info(String.format("Start:SendErc20 from:%s to:%s amount:%s erc20:%s", from, to, value.toString(), contractAddress));
        try {
            //         ，   
            Credentials credentials = Credentials.create(privateKey);
            //  nonce，    
            BigInteger nonce = getNonce(web3j, from);
            if (nonce == null) {
                logger.error(String.format("END:GetNonceError from:%s to:%s amount:%s erc20:%s", from, to, value.toString(), contractAddress));
                return null;
            }
            //gasPrice gasLimit        
            BigInteger gasPrice = getGasPrice(web3j);
            if (gasPrice == null) {
                logger.error(String.format("END:GetGasPriceError from:%s to:%s amount:%s erc20:%s", from, to, value.toString(), contractAddress));
                return null;
            }
            //BigInteger.valueOf(4300000L)                    
            BigInteger gasLimit = BigInteger.valueOf(60000L);
            //ERC20      
            Function function = new Function(
                    "transfer",
                    Arrays.asList(new Address(to), new Uint256(value)),
                    Collections.singletonList(new TypeReference() {
                    }));
            //  RawTransaction    
            String encodedFunction = FunctionEncoder.encode(function);
            RawTransaction rawTransaction = RawTransaction.createTransaction(nonce, gasPrice, gasLimit,
                    contractAddress, encodedFunction);

            //  Transaction
            byte[] signMessage = TransactionEncoder.signMessage(rawTransaction, credentials);
            String hexValue = Numeric.toHexString(signMessage);
            //    
            EthSendTransaction ethSendTransaction = web3j.ethSendRawTransaction(hexValue).sendAsync().get();
            String hash = ethSendTransaction.getTransactionHash();
            if (hash != null) {
                return hash;
            }
            logger.error(String.format("END:HashIsNull from:%s to:%s amount:%s erc20:%s", from, to, value.toString(), contractAddress));
        } catch (Throwable t) {
            System.out.println(t);
            logger.error(String.format("  ERC20   from=%s to=%s erc20=%s amount=%s",
                    from, to, contractAddress, value.toString()), t);
        }
        return null;
    }

 
다른 방법은 잠시 보류하고 시간이 있으면 다시 하자
문의 사항: laoxiang829