Java如何调用以太坊账户

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相关内容见之前笔记记录

导入Jar包

1. Java调用以太坊账户需要依赖web3j

   导入方式一：Maven

   	<dependency>
         <groupId>org.web3jgroupId>
         <artifactId>coreartifactId>
         <version>4.2.0version>
       dependency>
   

   导入方式二：下载jar包添加到项目library中

2. 导入日志包(同上)

       <dependency>
         <groupId>log4jgroupId>
         <artifactId>log4jartifactId>
         <version>1.2.17version>
         <scope>compilescope>
       dependency>
       <dependency>
         <groupId>org.slf4jgroupId>
         <artifactId>slf4j-apiartifactId>
         <version>1.7.18version>
         <scope>compilescope>
       dependency>
       <dependency>
         <groupId>org.slf4jgroupId>
         <artifactId>slf4j-log4j12artifactId>
         <version>1.7.18version>
         <scope>compilescope>
       dependency>
   

   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

运行程序

1. 运行程序

   可以发现控制台处于阻塞状态

   

2. 命令行的变化

   可以发现提交了一个交易（ transaction）

   

3. 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
   }
   >
   

4. 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
   }]
   >
   

5. 启动挖矿

   miner.start(1)

6. 控制台输出

   

   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)