Java如何调用以太坊账户以太坊

启动私链相关内容见之前笔记记录
导入Jar包

Java调用以太坊账户需要依赖web3j
导入方式一：Maven

org.web3j core 4.2.0

导入方式二：下载jar包添加到项目library中
导入日志包(同上)

log4j log4j 1.2.17 >compile org.slf4j slf4j-api 1.7.18 >compile org.slf4j slf4j-log4j12 1.7.18 >compile

否则运行可能会出现如下情况：
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

编写代码

import java.math.BigDecimal; import org.web3j.crypto.Credentials; import org.web3j.crypto.WalletUtils; import org.web3j.protocol.Web3j; import org.web3j.protocol.core.methods.response.TransactionReceipt; import org.web3j.protocol.http.HttpService; import org.web3j.tx.Transfer; import org.web3j.utils.Convert; import com.mao.utils.Consts; public class MainTest { public static void main(String[] argv) throws Exception { // 1.连接到以太坊网络上节点 // 默认参数为http://localhost:8545 // 下面两个语句等同 // Web3j web3j = Web3j.build(new HttpService()); Web3j web3j = Web3j.build(new HttpService("http://localhost:8545")); // 2.加载以太坊钱包参数说明：密码账户文件路径 // loadCredentials(String password, String source) Credentials credentials = WalletUtils.loadCredentials(Consts.PASSWORD, Consts.PATH); // 3.创建交易参数列表：网络钱包接收方地址数值单位 // sendFunds(Web3j web3j, Credentials credentials, String toAddress, BigDecimal // value, Unit unit) TransactionReceipt transferReceipt = Transfer.sendFunds(web3j, credentials, "0x118C56BAADdC4DA63aDD3B4bcf241681608ead71", BigDecimal.ONE, Convert.Unit.WEI).send(); // 4.输出交易的Hash值 System.out.println(transferReceipt.getTransactionHash()); } }

钱包加载说明：
password: 创建以太坊账户时设置的密码
source: 账户存储路径
例如：E:/BlockChain/node/data/keystore/UTC--2020-03-07T04-19-25.882222900Z--05a264bc64d6dd81492b1f5a4c93240d6ab15164

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运行程序

运行程序
可以发现控制台处于阻塞状态

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命令行的变化
可以发现提交了一个交易（ transaction）

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用 txpool.status命令可以看到本地交易池中有一个待确认的交易

> txpool.status { pending: 1, queued: 0 } >
可以使用eth.getBlock("pending", true).transactions查看当前待确认交易

> eth.getBlock("pending", true).transactions [{ blockHash: "0x05a1680dd4304acb5d5df4de5c6963fe8449764afee5bfe452a309180ae66234", blockNumber: 172, from: "0x05a264bc64d6dd81492b1f5a4c93240d6ab15164", gas: 21000, gasPrice: 1000000000, hash: "0xf841f29ff171685e36b527f039e09ca65282b643e5ce92e678449ef1d24ab815", input: "0x", nonce: 11, r: "0x629941aa58684b4dab5ef5f233bbc5c9360facf6cad615fbdaedf0d22493e0c7", s: "0x2892bd6e78f4f23db4f6a7e52eb1b8f186224fa7944c45543d41bf391b7d3bce", to: "0x118c56baaddc4da63add3b4bcf241681608ead71", transactionIndex: 0, v: "0x1c", value: 1 }] >
启动挖矿
miner.start(1)
控制台输出

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【Java如何调用以太坊账户】注意：当600秒内没有挖矿，将记录写入区块链，则会抛出异常

Exception in thread "main" org.web3j.protocol.exceptions.TransactionException: Transaction receipt was not generated after 600 seconds for transaction: 0xf841f29ff171685e36b527f039e09ca65282b643e5ce92e678449ef1d24ab815 at org.web3j.tx.response.PollingTransactionReceiptProcessor.getTransactionReceipt(PollingTransactionReceiptProcessor.java:51) at org.web3j.tx.response.PollingTransactionReceiptProcessor.waitForTransactionReceipt(PollingTransactionReceiptProcessor.java:29) at org.web3j.tx.TransactionManager.processResponse(TransactionManager.java:72) at org.web3j.tx.TransactionManager.executeTransaction(TransactionManager.java:51) at org.web3j.tx.ManagedTransaction.send(ManagedTransaction.java:87) at org.web3j.tx.Transfer.send(Transfer.java:65) at org.web3j.tx.Transfer.send(Transfer.java:49) at org.web3j.tx.Transfer.lambda$sendFunds$0(Transfer.java:76) at org.web3j.protocol.core.RemoteCall.send(RemoteCall.java:30) at com.mao.main.MainTest.main(MainTest.java:28)