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java中怎么监听以太坊交易

发表于：2025-02-01 作者：千家信息网编辑

千家信息网最后更新 2025年02月01日，java中怎么监听以太坊交易，针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。package com.bolenum.util;impo

千家信息网最后更新 2025年02月01日java中怎么监听以太坊交易

java中怎么监听以太坊交易，针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。

package com.bolenum.util;import java.io.IOException;import java.math.BigInteger;import java.util.ArrayList;import java.util...;import org.web3j.abi.EventEncoder;import org.web3j.abi...import org.web3j.crypto.Credentials;import org.web3j.protocol.Web3j;import org.web3j.protocol...;import org.web3j.tx.Contract;import org.web3j.tx.TransactionManager;import rx.Observable;import rx.functions.Func1;...public final class Erc20TokenWrapper extends Contract {    private static final String BINARY = "contract binary key";    private Erc20TokenWrapper(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {        super(BINARY, contractAddress, web3j, credentials, gasPrice, gasLimit);    }    private Erc20TokenWrapper(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {        super(BINARY, contractAddress, web3j, transactionManager, gasPrice, gasLimit);    }    public List getTransferEvents(TransactionReceipt transactionReceipt) {        ...        return responses;    }    public Observable transferEventObservable(DefaultBlockParameter startBlock, DefaultBlockParameter endBlock) {                ...        }        ...            public Uint256 balanceOf(Address _owner) throws IOException {        Function function = new Function("balanceOf",                 Arrays.asList(_owner),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }        ...            public TransactionReceipt transfer(Address _to, Uint256 _amount) throws IOException, TransactionException {        Function function = new Function("transfer", Arrays.asList(_to, _amount), Collections.>emptyList());        return executeTransaction(function);    }    ...       public static Erc20TokenWrapper load(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {        return new Erc20TokenWrapper(contractAddress, web3j, transactionManager, gasPrice, gasLimit);    }    public static class TransferEventResponse {        public Address _from;        public Address _to;        public Uint256 _value;        public String _transactionHash;    }                ...}

现在你必须使用这个类函数来加载合约然后监听交易。使用下面的代码加载和监听交易：

Web3j web3j = Web3j.build(new HttpService("url of your ethereum blockchain"))    ClientTransactionManager transactionManager = new ClientTransactionManager(web3j,                    "your deployed contract addess");            Erc20TokenWrapper token = Erc20TokenWrapper.load("your deployed contract addess", web3j, transactionManager,                    Contract.GAS_PRICE, Contract.GAS_LIMIT);            token.transferEventObservable(DefaultBlockParameterName.EARLIEST, DefaultBlockParameterName.LATEST)                    .subscribe(tx -> {                                   String toAddress = tx._to.getValue();                                   String fromAddress = tx._from.getValue();                                   String txHash = tx._transactionHash.getValue();                               }

如果你已经部署了合约，它由第三人部署，那么你可以直接使用我的包装类，只需更改你可以从https://etherscan.io/tokens很容易获得的二进制密钥。

结论：因此你可以将此代码用于任何token的监听交易。此代码为你提供address，fromAddress和transactionHash。所以这些东西你可以根据你的要求使用，你可以将它们保存在你的数据库中，或者你只保存地址是你的钱包地址的交易。

谢谢，我希望这会有所帮助。

如果希望快速进行web3j、java、以太坊开发，那请看我们精心打造的教程： java以太坊开发教程，主要是针对java和android程序员进行区块链以太坊开发的web3j详解。

这里是原文

完整代码如下：

package com.bolenum.util;import java.io.IOException;import java.math.BigInteger;import java.util.ArrayList;import java.util.Arrays;import java.util.Collections;import java.util.List;import java.util.concurrent.Future;import org.web3j.abi.EventEncoder;import org.web3j.abi.EventValues;import org.web3j.abi.FunctionEncoder;import org.web3j.abi.TypeReference;import org.web3j.abi.datatypes.Address;import org.web3j.abi.datatypes.Event;import org.web3j.abi.datatypes.Function;import org.web3j.abi.datatypes.Type;import org.web3j.abi.datatypes.Utf8String;import org.web3j.abi.datatypes.generated.Uint256;import org.web3j.abi.datatypes.generated.Uint8;import org.web3j.crypto.Credentials;import org.web3j.protocol.Web3j;import org.web3j.protocol.core.DefaultBlockParameter;import org.web3j.protocol.core.RemoteCall;import org.web3j.protocol.core.methods.request.EthFilter;import org.web3j.protocol.core.methods.response.Log;import org.web3j.protocol.core.methods.response.TransactionReceipt;import org.web3j.protocol.exceptions.TransactionException;import org.web3j.tx.Contract;import org.web3j.tx.TransactionManager;import rx.Observable;import rx.functions.Func1;/** * Auto generated code.
 * Do not modify!
 * Please use the web3j command line tools, or {@link org.web3j.codegen.SolidityFunctionWrapperGenerator} to update. * * Generated with web3j version 2.3.1. */public final class Erc20TokenWrapper extends Contract {    private static final String BINARY = "contract binary key";    private Erc20TokenWrapper(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {        super(BINARY, contractAddress, web3j, credentials, gasPrice, gasLimit);    }    private Erc20TokenWrapper(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {        super(BINARY, contractAddress, web3j, transactionManager, gasPrice, gasLimit);    }    public List getTransferEvents(TransactionReceipt transactionReceipt) {        final Event event = new Event("Transfer",                 Arrays.>asList(new TypeReference
() {}, new TypeReference() {}),                Arrays.>asList(new TypeReference() {}));        List valueList = extractEventParameters(event, transactionReceipt);        ArrayList responses = new ArrayList(valueList.size());        for (EventValues eventValues : valueList) {            TransferEventResponse typedResponse = new TransferEventResponse();            typedResponse._from = (Address) eventValues.getIndexedValues().get(0);            typedResponse._to = (Address) eventValues.getIndexedValues().get(1);            typedResponse._value = (Uint256) eventValues.getNonIndexedValues().get(0);            responses.add(typedResponse);        }        return responses;    }    public Observable transferEventObservable(DefaultBlockParameter startBlock, DefaultBlockParameter endBlock) {        final Event event = new Event("Transfer",                 Arrays.>asList(new TypeReference() {}, new TypeReference() {}),                Arrays.>asList(new TypeReference() {}));        EthFilter filter = new EthFilter(startBlock, endBlock, getContractAddress());        filter.addSingleTopic(EventEncoder.encode(event));        return web3j.ethLogObservable(filter).map(new Func1() {            @Override            public TransferEventResponse call(Log log) {                EventValues eventValues = extractEventParameters(event, log);                TransferEventResponse typedResponse = new TransferEventResponse();                typedResponse._from = (Address) eventValues.getIndexedValues().get(0);                typedResponse._to = (Address) eventValues.getIndexedValues().get(1);                typedResponse._value = (Uint256) eventValues.getNonIndexedValues().get(0);                typedResponse._transactionHash = log.getTransactionHash();                return typedResponse;            }        });    }    public List getApprovalEvents(TransactionReceipt transactionReceipt) {        final Event event = new Event("Approval",                 Arrays.>asList(new TypeReference() {}, new TypeReference() {}),                Arrays.>asList(new TypeReference() {}));        List valueList = extractEventParameters(event, transactionReceipt);        ArrayList responses = new ArrayList(valueList.size());        for (EventValues eventValues : valueList) {            ApprovalEventResponse typedResponse = new ApprovalEventResponse();            typedResponse._owner = (Address) eventValues.getIndexedValues().get(0);            typedResponse._spender = (Address) eventValues.getIndexedValues().get(1);            typedResponse._value = (Uint256) eventValues.getNonIndexedValues().get(0);            responses.add(typedResponse);        }        return responses;    }    public Observable approvalEventObservable(DefaultBlockParameter startBlock, DefaultBlockParameter endBlock) {        final Event event = new Event("Approval",                 Arrays.>asList(new TypeReference() {}, new TypeReference() {}),                Arrays.>asList(new TypeReference() {}));        EthFilter filter = new EthFilter(startBlock, endBlock, getContractAddress());        filter.addSingleTopic(EventEncoder.encode(event));        return web3j.ethLogObservable(filter).map(new Func1() {            @Override            public ApprovalEventResponse call(Log log) {                EventValues eventValues = extractEventParameters(event, log);                ApprovalEventResponse typedResponse = new ApprovalEventResponse();                typedResponse._owner = (Address) eventValues.getIndexedValues().get(0);                typedResponse._spender = (Address) eventValues.getIndexedValues().get(1);                typedResponse._value = (Uint256) eventValues.getNonIndexedValues().get(0);                typedResponse._transactionHash = log.getTransactionHash();                return typedResponse;            }        });    }    public Future name() throws IOException {        Function function = new Function("name",                 Arrays.asList(),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public TransactionReceipt approve(Address _spender, Uint256 _amount) throws IOException, TransactionException {        Function function = new Function("approve", Arrays.asList(_spender, _amount), Collections.>emptyList());        return executeTransaction(function);    }    public Future totalSupply() throws IOException {        Function function = new Function("totalSupply",                 Arrays.asList(),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public TransactionReceipt transferFrom(Address _from, Address _to, Uint256 _amount) throws IOException, TransactionException {        Function function = new Function("transferFrom", Arrays.asList(_from, _to, _amount), Collections.>emptyList());        return  executeTransaction(function);    }    public Uint8 decimals() throws IOException {        Function function = new Function("decimals",                 Arrays.asList(),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public Uint256 balanceOf(Address _owner) throws IOException {        Function function = new Function("balanceOf",                 Arrays.asList(_owner),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public Future owner() throws IOException {        Function function = new Function("owner",                 Arrays.asList(),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public Future symbol() throws IOException {        Function function = new Function("symbol",                 Arrays.asList(),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public TransactionReceipt transfer(Address _to, Uint256 _amount) throws IOException, TransactionException {        Function function = new Function("transfer", Arrays.asList(_to, _amount), Collections.>emptyList());        return executeTransaction(function);    }    public Future allowance(Address _owner, Address _spender) throws IOException {        Function function = new Function("allowance",                 Arrays.asList(_owner, _spender),                 Arrays.>asList(new TypeReference() {}));        return executeCallSingleValueReturn(function);    }    public static RemoteCall deploy(Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit, BigInteger initialWeiValue, Uint256 totalSupply, Utf8String tokenName, Uint8 decimalUnits, Utf8String tokenSymbol) {        String encodedConstructor = FunctionEncoder.encodeConstructor(Arrays.asList(totalSupply, tokenName, decimalUnits, tokenSymbol));        return deployRemoteCall(Erc20TokenWrapper.class, web3j, credentials, gasPrice, gasLimit, BINARY, encodedConstructor, initialWeiValue);    }    public static RemoteCall deploy(Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit, BigInteger initialWeiValue, Uint256 totalSupply, Utf8String tokenName, Uint8 decimalUnits, Utf8String tokenSymbol) {        String encodedConstructor = FunctionEncoder.encodeConstructor(Arrays.asList(totalSupply, tokenName, decimalUnits, tokenSymbol));        return deployRemoteCall(Erc20TokenWrapper.class, web3j, transactionManager, gasPrice, gasLimit, BINARY, encodedConstructor, initialWeiValue);    }    public static Erc20TokenWrapper load(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {        return new Erc20TokenWrapper(contractAddress, web3j, credentials, gasPrice, gasLimit);    }    public static Erc20TokenWrapper load(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {        return new Erc20TokenWrapper(contractAddress, web3j, transactionManager, gasPrice, gasLimit);    }    public static class TransferEventResponse {        public Address _from;        public Address _to;        public Uint256 _value;        public String _transactionHash;    }    public static class ApprovalEventResponse {        public Address _owner;        public Address _spender;        public Uint256 _value;        public String _transactionHash;    }}