이 페이지는 영어로 된 기계 번역을 사용하므로 오류나 불명확한 언어가 포함될 수 있습니다. 가장 정확한 정보는 영어 원문을 참조하시기 바랍니다. 잦은 업데이트로 인해 일부 콘텐츠는 원래 영어로 되어 있을 수 있습니다. Crowdin에서 이 페이지의 번역을 개선하는 데 동참하여 도움을 주세요. (Crowdin translation page, Contributing guide)

Value Transfer Memo

TxTypeValueTransferMemo is used when a user wants to send KAIA with a specific message.

Import necessary classes from the Web3j and kaia libraries(web3j-ext).

Connect to the kaia blockchain using Web3j and specify the URL

Create KlayCredentials using the private key

Define gas price and gas limit for the transaction

Get the sender's address from credentials.getAddress()

Get the chain ID from the Kaia network

Initialize variables for transaction parameters

Create a raw transaction object.

Sign the raw transaction

Send the transaction to kaia network.

Get the transaction receipt and using the transaction hash

Shut down the Web3j connection

Decode the raw transaction to get the transaction type

ValueTransferMemo.java

package org.web3j.example.transactions;

import java.io.IOException;

import java.math.BigInteger;

import org.web3j.crypto.KlayCredentials;

import org.web3j.crypto.KlayRawTransaction;

import org.web3j.crypto.KlayTransactionEncoder;

import org.web3j.crypto.transaction.type.TxType;

import org.web3j.crypto.transaction.type.TxTypeValueTransferMemo;

import org.web3j.crypto.transaction.type.TxType.Type;

import org.web3j.protocol.core.DefaultBlockParameterName;

import org.web3j.protocol.core.methods.response.EthChainId;

import org.web3j.protocol.core.methods.response.EthSendTransaction;

import org.web3j.protocol.http.HttpService;

import org.web3j.protocol.kaia.Web3j;

import org.web3j.utils.Numeric;

import org.web3j.protocol.kaia.core.method.response.TransactionReceipt;

import org.web3j.tx.response.PollingTransactionReceiptProcessor;

import org.web3j.tx.response.TransactionReceiptProcessor;

import org.web3j.example.keySample;

/**

*

*/

public class ValueTransferMemoExample implements keySample {

/**

*

*/

public static void run() throws Exception {

Web3j web3j = Web3j.build(new HttpService(keySample.BAOBAB_URL));

KlayCredentials credentials = KlayCredentials.create(keySample.LEGACY_KEY_privkey);

BigInteger GAS_PRICE = BigInteger.valueOf(50000000000L);

BigInteger GAS_LIMIT = BigInteger.valueOf(6721950);

String from = credentials.getAddress();

EthChainId EthchainId = web3j.ethChainId().send();

long chainId = EthchainId.getChainId().longValue();

String to = "0x000000000000000000000000000000000000dead";

BigInteger nonce = web3j.ethGetTransactionCount(from, DefaultBlockParameterName.LATEST).send()

.getTransactionCount();

BigInteger value = BigInteger.valueOf(100);

String data = "Kaia Web3j";

byte[] payload = data.getBytes();

TxType.Type type = Type.VALUE_TRANSFER_MEMO;

KlayRawTransaction raw = KlayRawTransaction.createTransaction(

type,

nonce,

GAS_PRICE,

GAS_LIMIT,

to,

value,

from,

payload);

byte[] signedMessage = KlayTransactionEncoder.signMessage(raw, chainId, credentials);

String hexValue = Numeric.toHexString(signedMessage);

EthSendTransaction transactionResponse = web3j.ethSendRawTransaction(hexValue).send();

System.out.println("TxHash : \n " + transactionResponse.getResult());

String txHash = transactionResponse.getResult();

int DEFAULT_POLLING_ATTEMPTS_PER_TX_HASH = 40;

int DEFAULT_BLOCK_TIME = 1 * 1000;

long DEFAULT_POLLING_FREQUENCY = DEFAULT_BLOCK_TIME;

TransactionReceiptProcessor transactionReceiptProcessor = new PollingTransactionReceiptProcessor(web3j,

DEFAULT_POLLING_FREQUENCY, DEFAULT_POLLING_ATTEMPTS_PER_TX_HASH);

org.web3j.protocol.core.methods.response.TransactionReceipt ethReceipt = transactionReceiptProcessor

.waitForTransactionReceipt(txHash);

System.out.println("Receipt from eth_getTransactionReceipt : \n" + ethReceipt);

TransactionReceipt receipt = web3j.klayGetTransactionReceipt(txHash).send().getResult();

System.out.println("Receipt from klay_getTransactionReceipt : \n" + receipt);

web3j.shutdown();

TxTypeValueTransferMemo rawTransaction = TxTypeValueTransferMemo.decodeFromRawTransaction(signedMessage);

System.out.println("TxType : " + rawTransaction.getKlayType());

}

}

output

❯ java ValueTransferMemo.java

output