ETH私有链搭建与使用-java调用智能合约方法(4)
java调用智能合约方法
1.准备智能合约java类
1.1下载与pom.xml中web3j相同版本的命令行操作工具
下载链接: https://mituxiaogaoyang.club/eth-source/web3j-4.5.0.zip
1.2解压zip文件进入bin目录
将SimpleStorage_sol_SimpleStorage.abi和SimpleStorage_sol_SimpleStorage.bin文件从服务器下载到本地这个目录中,这两个文件是上一篇文章中solc编译出来的文件.
1.3通过web3j命令行工具将合约转换为java类
web3j solidity generate -a SimpleStorage_sol_SimpleStorage.abi -b SimpleStorage_sol_SimpleStorage.bin -o ./output -p com.fc.v2.web3j
转换成功如上图所示,对应文件夹下会生成相应的java类.
2.编写调用合约方法
2.1引入pom依赖
<!-- web3j依赖 --><dependency>
<groupId>org.web3j</groupId>
<artifactId>core</artifactId>
<version>4.5.0</version>
</dependency>
2.2复制SimpleStorage_sol_SimpleStorage.java类到项目中
2.3在SimpleStorage_sol_SimpleStorage.java中新增一个合约方法来获取返回值
// 新增获取返回值方法public RemoteFunctionCall<BigInteger> getForReturn() {
final Function function = new Function(
FUNC_GET,
Collections.emptyList(),
Arrays.asList(new TypeReference<Uint256>(){}));
return executeRemoteCallSingleValueReturn(function, BigInteger.class);
}
完整SimpleStorage_sol_SimpleStorage.java代码如下:
package com.fc.v2.web3j;import java.math.BigInteger;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.web3j.abi.TypeReference;
import org.web3j.abi.datatypes.Function;
import org.web3j.abi.datatypes.Type;
import org.web3j.abi.datatypes.generated.Uint256;
import org.web3j.crypto.Credentials;
import org.web3j.protocol.Web3j;
import org.web3j.protocol.core.RemoteCall;
import org.web3j.protocol.core.RemoteFunctionCall;
import org.web3j.protocol.core.methods.response.TransactionReceipt;
import org.web3j.tx.Contract;
import org.web3j.tx.TransactionManager;
import org.web3j.tx.gas.ContractGasProvider;
/**
* <p>Auto generated code.
* <p><span>Do not modify!</span>
* <p>Please use the <a href="https://docs.web3j.io/command_line.html">web3j command line tools</a>,
* or the org.web3j.codegen.SolidityFunctionWrapperGenerator in the
* <a href="https://github.com/web3j/web3j/tree/master/codegen">codegen module</a> to update.
*
* <p>Generated with web3j version 4.5.0.
*/
public class SimpleStorage_sol_SimpleStorage extends Contract {
private static final String BINARY = "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";
public static final String FUNC_GET = "get";
public static final String FUNC_SET = "set";
@Deprecated
protected SimpleStorage_sol_SimpleStorage(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {
super(BINARY, contractAddress, web3j, credentials, gasPrice, gasLimit);
}
protected SimpleStorage_sol_SimpleStorage(String contractAddress, Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider) {
super(BINARY, contractAddress, web3j, credentials, contractGasProvider);
}
@Deprecated
protected SimpleStorage_sol_SimpleStorage(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {
super(BINARY, contractAddress, web3j, transactionManager, gasPrice, gasLimit);
}
protected SimpleStorage_sol_SimpleStorage(String contractAddress, Web3j web3j, TransactionManager transactionManager, ContractGasProvider contractGasProvider) {
super(BINARY, contractAddress, web3j, transactionManager, contractGasProvider);
}
public RemoteFunctionCall<TransactionReceipt> get() {
final Function function = new Function(
FUNC_GET,
Arrays.<Type>asList(),
Collections.<TypeReference<?>>emptyList());
return executeRemoteCallTransaction(function);
}
public RemoteFunctionCall<TransactionReceipt> set(BigInteger x) {
final Function function = new Function(
FUNC_SET,
Arrays.<Type>asList(new org.web3j.abi.datatypes.generated.Uint256(x)),
Collections.<TypeReference<?>>emptyList());
return executeRemoteCallTransaction(function);
}
// 新增获取返回值方法
public RemoteFunctionCall<BigInteger> getForReturn() {
final Function function = new Function(
FUNC_GET,
Collections.emptyList(),
Arrays.asList(new TypeReference<Uint256>(){}));
return executeRemoteCallSingleValueReturn(function, BigInteger.class);
}
@Deprecated
public static SimpleStorage_sol_SimpleStorage load(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {
return new SimpleStorage_sol_SimpleStorage(contractAddress, web3j, credentials, gasPrice, gasLimit);
}
@Deprecated
public static SimpleStorage_sol_SimpleStorage load(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {
return new SimpleStorage_sol_SimpleStorage(contractAddress, web3j, transactionManager, gasPrice, gasLimit);
}
public static SimpleStorage_sol_SimpleStorage load(String contractAddress, Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider) {
return new SimpleStorage_sol_SimpleStorage(contractAddress, web3j, credentials, contractGasProvider);
}
public static SimpleStorage_sol_SimpleStorage load(String contractAddress, Web3j web3j, TransactionManager transactionManager, ContractGasProvider contractGasProvider) {
return new SimpleStorage_sol_SimpleStorage(contractAddress, web3j, transactionManager, contractGasProvider);
}
public static RemoteCall<SimpleStorage_sol_SimpleStorage> deploy(Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider) {
return deployRemoteCall(SimpleStorage_sol_SimpleStorage.class, web3j, credentials, contractGasProvider, BINARY, "");
}
@Deprecated
public static RemoteCall<SimpleStorage_sol_SimpleStorage> deploy(Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {
return deployRemoteCall(SimpleStorage_sol_SimpleStorage.class, web3j, credentials, gasPrice, gasLimit, BINARY, "");
}
public static RemoteCall<SimpleStorage_sol_SimpleStorage> deploy(Web3j web3j, TransactionManager transactionManager, ContractGasProvider contractGasProvider) {
return deployRemoteCall(SimpleStorage_sol_SimpleStorage.class, web3j, transactionManager, contractGasProvider, BINARY, "");
}
@Deprecated
public static RemoteCall<SimpleStorage_sol_SimpleStorage> deploy(Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {
return deployRemoteCall(SimpleStorage_sol_SimpleStorage.class, web3j, transactionManager, gasPrice, gasLimit, BINARY, "");
}
}
2.4编写Web3jDemo.java测试类,完整代码如下
package com.fc.v2.web3j;import java.math.BigInteger;
import org.web3j.crypto.Credentials;
import org.web3j.crypto.RawTransaction;
import org.web3j.crypto.TransactionEncoder;
import org.web3j.crypto.WalletUtils;
import org.web3j.protocol.Web3j;
import org.web3j.protocol.admin.Admin;
import org.web3j.protocol.admin.methods.response.PersonalUnlockAccount;
import org.web3j.protocol.core.DefaultBlockParameterName;
import org.web3j.protocol.core.methods.response.EthGetBalance;
import org.web3j.protocol.core.methods.response.EthGetTransactionCount;
import org.web3j.protocol.core.methods.response.EthSendTransaction;
import org.web3j.protocol.core.methods.response.TransactionReceipt;
import org.web3j.protocol.http.HttpService;
import org.web3j.tx.RawTransactionManager;
import org.web3j.tx.TransactionManager;
import org.web3j.tx.gas.ContractGasProvider;
import org.web3j.tx.gas.StaticGasProvider;
import org.web3j.utils.Convert;
import org.web3j.utils.Numeric;
public class Web3jDemo {
private static final String RPC_URL = "http://116.62.58.222:8545";//RPC访问地址,由节点设置,请替换成自己节点的rpc地址
private static final Web3j web3j = Web3j.build(new HttpService(RPC_URL));//Web3j客户端
private static final Admin adminWeb3j = Admin.build(new HttpService(RPC_URL));//Admin管理端
private static final String address = "0xffd4a30c08d9f16f095f6315e14bd034f7d04fb0";//有余额的钱包地址
private static final String password = "123456";//钱包地址解锁密码
private static final String to = "0x1ef3c8b97c47ba09d01be4a0cf633d9f08ef4cd1";//转出的钱包地址
private static final String filePath = "D:\\wallet";//有余额的钱包地址私钥文件路径
private static final long chainId = 666l;//创世区块json文件中的chainId
private static final BigInteger gasPrice = new BigInteger("5000");//燃料消耗
private static final BigInteger gasLimit = new BigInteger("300000");//消耗限制
private static final String contractAddress = "0xd74859b57c108dffae39bfe6c1bf9cea67b527ea";//合约地址,部署合约成功后会返回该地址
//测试主函数
public static void main(String[] args) throws Exception {
// getAge(to);
// sendTransaction();
excuteContract();
}
// 查询钱包余额
public static void getAge(String address) throws Exception {
// 这里要填写真实的钱包地址
EthGetBalance ethGetBalance = web3j
.ethGetBalance(address, DefaultBlockParameterName.LATEST).send();
if (ethGetBalance != null) {
System.out.println("余额:" + Convert.fromWei(ethGetBalance.getBalance().toString(), Convert.Unit.ETHER));
}
}
// 发送转账交易
public static void sendTransaction() throws Exception {
PersonalUnlockAccount personalUnlockAccount = adminWeb3j.personalUnlockAccount(address, password).send();
if (personalUnlockAccount.accountUnlocked()) {
BigInteger gasPrice = web3j.ethGasPrice().sendAsync().get().getGasPrice();
System.out.println(gasPrice);
// send a transaction
EthGetTransactionCount ethGetTransactionCount = web3j.ethGetTransactionCount(address, DefaultBlockParameterName.LATEST).sendAsync().get();
BigInteger nonce = ethGetTransactionCount.getTransactionCount();
RawTransaction rawTransaction = RawTransaction.createEtherTransaction(nonce, new BigInteger("5000"), new BigInteger("300000"), to, new BigInteger("3"));
// 对交易进行签名和编码：
// String fileName = WalletUtils.generateNewWalletFile(password, new File(filePath));
String fileName = "UTC--2021-10-12T07-07-33.666057600Z--ffd4a30c08d9f16f095f6315e14bd034f7d04fb0";
Credentials credentials = WalletUtils.loadCredentials(password, filePath + "\\" + fileName);
byte[] signedMessage = TransactionEncoder.signMessage(rawTransaction, chainId, credentials);
String hexValue = Numeric.toHexString(signedMessage);
EthSendTransaction ethSendTransaction = web3j.ethSendRawTransaction(hexValue).sendAsync().get();
String transactionHash = ethSendTransaction.getTransactionHash();
System.out.println("transactionHash:"+transactionHash);
}
}
// 执行合约方法
public static void excuteContract() throws Exception {
// 私钥文件名
String fileName = "UTC--2021-10-12T07-07-33.666057600Z--ffd4a30c08d9f16f095f6315e14bd034f7d04fb0";
Credentials credentials = WalletUtils.loadCredentials(password, filePath + "\\" + fileName);
ContractGasProvider contractGasProvider = new StaticGasProvider(gasPrice, gasLimit);
TransactionManager transactionManager = new RawTransactionManager(web3j, credentials, chainId);
SimpleStorage_sol_SimpleStorage contract = SimpleStorage_sol_SimpleStorage.load(contractAddress, web3j, transactionManager, contractGasProvider);
System.out.println(contract.isValid());//验证合约是否有效,返回true代表有效
TransactionReceipt result = contract.set(new BigInteger("88")).send();//调用合约方法(阻塞形式),节点需开启挖矿并等待挖矿后进入到下一步
System.out.println(result.getTransactionHash());//打印交易hash
BigInteger data = contract.getForReturn().send();//调用合约方法获取数据,节点无需开启挖矿
System.out.println(data);//打印返回数据
}
}
2.5从服务器拷贝私钥文件到本地对应路径
服务器私钥文件路径:
本地路径:
2.6运行代码查看测试打印结果
至此,数据"88"已经存储到了eth私有链上,并能够被合约正常取出.
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