本页面使用机器翻译自英语，可能包含错误或不清楚的语言。如需最准确的信息，请参阅英文原文。由于更新频繁，部分内容可能与英文原文有出入。请加入我们在 Crowdin 上的努力，帮助我们改进本页面的翻译。 (Crowdin translation page, Contributing guide)

Web3j extension for kaia

要求

设置 Java

• 使用 java 版本： 11 <= v <= 18
• 访问 https://adoptopenjdk.net/ 网站
• 下载 OpenJDK

安装 Web3j kaia 扩展

将 Gradle 库 添加到项目中：

repositories {

mavenCentral()

}

dependencies {

implementation "foundation.klaytn:web3j-ext:v0.9.3"

implementation "foundation.klaytn:web3rpc-java:v0.9.0"

implementation "org.web3j:core:4.9.8"

}

用法

请参见 [example]（./web3j-ext/src/main/java/org/web3j/example）。

快速入门

关于 web3j 的基本用法，您可以通过 Web3j tutorial 学习。

在 Kairos Testnet 上发送费用委托交易

如果您想进一步了解 kaia 网络支持的收费委托交易的概念，请参阅 kaiadocs。

检查 web3j-ext examples 中的 FeeDelegatedValueTransferExample.java 文件。

package org.web3j.example;

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.TxTypeValueTransfer;

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;

public class FeeDelegatedValueTransferExample 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);

KlayCredentials credentials_feepayer = KlayCredentials.create(keySample.LEGACY_KEY_FEEPAYER_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.EthChainId.getChainId().longValue()ethGetTransactionCount(from, DefaultBlockParameterName.LATEST).send()

.getTransactionCount();

BigInteger value = BigInteger.valueOf(100);

TxType.Type type = Type.FEE_DELEGATED_VALUE_TRANSFER;

KlayRawTransaction raw = KlayRawTransaction.createTransaction(

type,

nonce,

GAS_PRICE,

GAS_LIMIT,

to,

value,

from);

// Sign as sender

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

// Sign same message as Fee payer

signedMessage = KlayTransactionEncoder.signMessageAsFeePayer(raw, chainId, credentials_feepayer);

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();

TxTypeFeeDelegatedValueTransfer rawTransaction = TxTypeFeeDelegatedValueTransfer

.decodeFromRawTransaction(hexValue);

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

}

}

运行示例

import org.web3j.example.FeeDelegatedValueTransferExample;

public class quickstart {

public static void main(String[] args) throws Exception {

FeeDelegatedValueTransferExample.run();

}

}