eth和erc20代码接入

Posted 2021-06-17 小牤牤她爸_老乡

基于web3j

创建地址

    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("创建地址失败", t);
        }
        return null;
    }

 

查询erc20余额

    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("查询ERC20失败 contract:%s address:%s", contract, address), t);
        }
        return BigInteger.ZERO;
    }

发送erc20

    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 {
            //加载转账所需的凭证，用私钥
            Credentials credentials = Credentials.create(privateKey);
            //获取nonce，交易笔数
            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和gasLimit 都可以手动设置
            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) 如果交易失败 很可能是手续费的设置问题
            BigInteger gasLimit = BigInteger.valueOf(60000L);
            //ERC20代币合约方法
            Function function = new Function(
                    "transfer",
                    Arrays.asList(new Address(to), new Uint256(value)),
                    Collections.singletonList(new TypeReference<Type>() {
                    }));
            //创建RawTransaction交易对象
            String encodedFunction = FunctionEncoder.encode(function);
            RawTransaction rawTransaction = RawTransaction.createTransaction(nonce, gasPrice, gasLimit,
                    contractAddress, encodedFunction);

            //签名Transaction
            byte[] signMessage = TransactionEncoder.signMessage(rawTransaction, credentials);
            String hexValue = Numeric.toHexString(signMessage);
            //发送交易
            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("发送ERC20失败 from=%s to=%s erc20=%s amount=%s",
                    from, to, contractAddress, value.toString()), t);
        }
        return null;
    }

 

其他方法暂不贴了，有时间再弄

需要帮助的联系：laoxiang829