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中国广东省深圳市龙华新区民治街道溪山美地
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<netkiller@msn.com>
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2018-02-04
摘要
本文采用碎片化写作，原文会不定期更新，请尽量阅读原文。
http://www.netkiller.cn/journal/ethereum.solidity.html
目录
Truffle 是 solidity 开发框架
# 安装 Nodejs curl -sL https://deb.nodesource.com/setup_9.x | sudo -E bash - sudo apt-get install -y nodejs # 安装truffle sudo npm install -g truffle # 安装testrpc sudo npm install -g ethereumjs-testrpc
cd ~/ethereum mkdir truffle-project cd truffle-project truffle init
操作演示
neo@netkiller ~/ethereum/truffle-project % truffle init Downloading... Unpacking... Setting up... Unbox successful. Sweet! Commands: Compile: truffle compile Migrate: truffle migrate Test contracts: truffle test neo@netkiller ~/ethereum/truffle-project % tree . |-- contracts | `-- Migrations.sol |-- migrations | `-- 1_initial_migration.js |-- test |-- truffle-config.js `-- truffle.js 3 directories, 4 files
打开文件 truffle.js
module.exports = { // See <http://truffleframework.com/docs/advanced/configuration> // to customize your Truffle configuration! }; 修改为
module.exports = { // See <http://truffleframework.com/docs/advanced/configuration> // to customize your Truffle configuration! networks: { development: { host: "localhost", port: 8545, network_id: "*" // Match any network id } } }; neo@netkiller ~/ethereum/truffle-project % truffle compile Compiling ./contracts/Migrations.sol... Writing artifacts to ./build/contracts
truffle默认只会编译最后一次修改过的合约文件, 这是为了减少比重复编译。"--all"选项,可以强制编译所有文件。
编译结果
neo@netkiller ~/ethereum/truffle-project % find build build build/contracts build/contracts/Migrations.json
neo@netkiller ~/ethereum/truffle-project % truffle migrate Using network 'development'. Network up to date.
neo@netkiller ~/ethereum/truffle-project % truffle deploy Using network 'development'. Network up to date.
在线使用 browser-solidity
https://ethereum.github.io/browser-solidity/ https://remix.ethereum.org/
国内网络有时不给力，建议将 Remix 安装到本地目录。
共享合约目录
npm install -g remixd remixd -S "/home/ethereum/codebase/blocks/contracts"
安装 browser-solidity
git clone https://github.com/ethereum/browser-solidity cd browser-solidity npm install npm run prepublish sudo chown -R $USER:$(id -gn $USER) /home/neo/.config npm start
启动后浏览器中输入 http://localhost:8080 可以看到 Remix 界面
Remix 提供三种运行环境,常用的有 JavaScript VM 和 Web3 Provider (连接到 --rpc --rpcaddr="0.0.0.0" --rpccorsdomain "*" --rpcport 8545)
Web3 Provider 方式需要解锁账号和启动挖矿
> personal.unlockAccount(eth.accounts[0],""); > miner.start(2); admin.sleepBlocks(1); miner.stop();
neo@netkiller ~/ethereum/solidity % solc --bin --abi --optimize -o ./output helloworld.sol neo@netkiller ~/ethereum/solidity % find output output output/HelloWorld.bin output/HelloWorld.abi
Solidity 是什么？Solidity是以太坊智能合约的编程语言。
这里我们先做一个 Helloword 演示，让你初步对智能合约有一个大概的认识。
需要注意的是，你在网上会看到很多例子，对照这例子一步一步操作，始终无法成功，这根Solidity的版本有很大关系。
将下面代码粘贴到
pragma solidity ^0.4.19; contract HelloWorld { string tmp; function HelloWorld() public { } function get() public constant returns (string) { return tmp; } function set(string _tmp) public { tmp = _tmp; } } Compile - Details - WEB3DEPLOY
var helloworldContract = web3.eth.contract([{"constant":false,"inputs":[{"name":"_tmp","type":"string"}],"name":"set","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]); var helloworld = helloworldContract.new( { from: web3.eth.accounts[0], data: '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', gas: '4700000' }, function (e, contract){ console.log(e, contract); if (typeof contract.address !== 'undefined') { console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash); } }) 部署智能合约需要消耗 gas 所以你要先解锁账号。
> personal.unlockAccount("0x83fda0ba7e6cfa8d7319d78fa0e6b753a2bcb5a6", "", 300) true > var helloworldContract = web3.eth.contract([{"constant":false,"inputs":[{"name":"_tmp","type":"string"}],"name":"set","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]); undefined > var helloworld = helloworldContract.new( ... { ...... from: web3.eth.accounts[0], ...... data: '0x6060604052341561000f57600080fd5b6102e38061001e6000396000f30060606040526004361061004c576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff1680634ed3885e146100515780636d4ce63c146100ae575b600080fd5b341561005c57600080fd5b6100ac600480803590602001908201803590602001908080601f0160208091040260200160405190810160405280939291908181526020018383808284378201915050505050509190505061013c565b005b34156100b957600080fd5b6100c1610156565b6040518080602001828103825283818151815260200191508051906020019080838360005b838110156101015780820151818401526020810190506100e6565b50505050905090810190601f16801561012e5780820380516001836020036101000a031916815260200191505b509250505060405180910390f35b80600090805190602001906101529291906101fe565b5050565b61015e61027e565b60008054600181600116156101000203166002900480601f0160208091040260200160405190810160405280929190818152602001828054600181600116156101000203166002900480156101f45780601f106101c9576101008083540402835291602001916101f4565b820191906000526020600020905b8154815290600101906020018083116101d757829003601f168201915b5050505050905090565b828054600181600116156101000203166002900490600052602060002090601f016020900481019282601f1061023f57805160ff191683800117855561026d565b8280016001018555821561026d579182015b8281111561026c578251825591602001919060010190610251565b5b50905061027a9190610292565b5090565b602060405190810160405280600081525090565b6102b491905b808211156102b0576000816000905550600101610298565b5090565b905600a165627a7a72305820ea826c30d131f20a4d3a8e3fb059ffa95f4c222a5b099029750e4c1937b46e5b0029', ...... gas: '4700000' ...... }, function (e, contract){ ...... console.log(e, contract); ...... if (typeof contract.address !== 'undefined') { ......... console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash); ......... } ...... }) null [object Object] undefined helloworld 智能合约已经创建完毕
> helloworld { abi: [{ constant: false, inputs: [{...}], name: "set", outputs: [], payable: false, stateMutability: "nonpayable", type: "function" }, { constant: true, inputs: [], name: "get", outputs: [{...}], payable: false, stateMutability: "view", type: "function" }, { inputs: [], payable: false, stateMutability: "nonpayable", type: "constructor" }], address: undefined, transactionHash: "0x466c9ad9db8f37ed5b65bc261210da92f51364ebab1dcbd3759bfc3e16ad6502" } public ： 函数可见性 payable ：可支付的函数修饰符，没有该修饰符无法接受转账操作。 msg.value ：执行合约时，转账的eth数量，以wei为单位。 msg.sender : 执行合约的地址
uint 无符号整形（256bits 无符号整数）
string 字符串类型
//创建一个memory的数组 uint[] memory a = new uint[](7); uint[] x = [uint(1), 3, 4];
pragma solidity ^0.4.0; contract Purchase { enum State { Created, Locked, Inactive } // Enum } 定义结构体
struct Voter { uint weight; // weight is accumulated by delegation bool voted; // if true, that person already voted address delegate; // person delegated to uint vote; // index of the voted proposal } // This is a type for a single proposal. struct Proposal { bytes32 name; // short name (up to 32 bytes) uint voteCount; // number of accumulated votes } address public minter; string name; int num; uint constant x = 32**22 + 8; string constant text = "abc"; bytes32 constant myHash = keccak256("abc"); uint256 ticket = 1 ether; 变量赋值
pragma solidity ^0.4.19; contract C { uint[] data; function f() public view returns (uint, bool, uint) { return (7, true, 2); } function g() public { // 声明和分配变量。 明确指定类型是不可能的。 var (x, b, y) = f(); // 分配给一个预先存在的变量。 (x, y) = (2, 7); // 互换值的常用技巧对于非价值存储类型不起作用。 (x, y) = (y, x); // 组件可以省略（也可以用于变量声明）。 // 如果元组以空组件结束，其余的值将被丢弃。 (data.length,) = f(); // 设置长度为 7 // 在左边也可以做同样的事情。 (,data[3]) = f(); // Sets data[3] to 2 // 组件只能在作业的左侧排除，但有一个例外： (x,) = (1,); // (1,) 是指定1元组元的唯一方法，因为（1）等于1。 } } 构造方法的定义是 contract 与 function 相同
pragma solidity ^0.4.18; contract MyContractByNetkiller { /* Constructor */ function MyContractByNetkiller() public{ } } 没有返回值
function setName(string _name) public{ name = _name; } 有返回值
function getName() public view returns(string){ return name; } 除了 f(2,3) 这样传递参数，还可以使用类似字典或Map的方式 f({value: 2, key: 3});
pragma solidity ^0.4.0; contract C { function f(uint key, uint value) { // ... } function g() { // named arguments f({value: 2, key: 3}); } } 完整的例子
pragma solidity ^0.4.18; contract MyContractByNetkiller { /* Constructor */ string name; int num; function MyContractByNetkiller() public{ name = "default"; num = 1; } function setName(string _name) public{ name = _name; } function getName() public view returns(string){ return name; } function setNum(int n) public{ num = n; } function addNum(int m) public view returns(int res){ res = m + num; } } event Sent(address from, address to, uint amount);
官方网站 https://web3j.io
Java 客户端与 Server 之间采用json-rpc协议连接。
web3j 命令用于将 sol 合约文件转换为 java 文件。
brew tap web3j/web3j brew install web3j neo@MacBook-Pro ~ % web3j _ _____ _ _ | | |____ (_) (_) __ _____| |__ / /_ _ ___ \ \ /\ / / _ \ '_ \ \ \ | | | / _ \ \ V V / __/ |_) |.___/ / | _ | || (_) | \_/\_/ \___|_.__/ \____/| |(_)|_| \___/ _/ | |__/ Usage: web3j version|wallet|solidity ...
下载二进制文件 https://github.com/web3j/web3j/releases
wget https://github.com/web3j/web3j/releases/download/v3.2.0/web3j-3.2.0.zip unzip web3j-3.2.0.zip $ ./web3j-3.2.0/bin/web3j _ _____ _ _ | | |____ (_) (_) __ _____| |__ / /_ _ ___ \ \ /\ / / _ \ '_ \ \ \ | | | / _ \ \ V V / __/ |_) |.___/ / | _ | || (_) | \_/\_/ \___|_.__/ \____/| |(_)|_| \___/ _/ | |__/ Usage: web3j version|wallet|solidity ...
首先启动服务
neo@netkiller ~ % geth --networkid 123456 --rpc --rpcaddr="0.0.0.0" --rpccorsdomain "*" --nodiscover INFO [02-01|23:35:12] Starting peer-to-peer node instance=Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9.1 INFO [02-01|23:35:12] Allocated cache and file handles database=/home/neo/.ethereum/geth/chaindata cache=128 handles=1024 INFO [02-01|23:35:12] Initialised chain configuration config="{ChainID: 15 Homestead: 0 DAO: <nil> DAOSupport: false EIP150: <nil> EIP155: 0 EIP158: 0 Byzantium: <nil> Engine: unknown}" INFO [02-01|23:35:12] Disk storage enabled for ethash caches dir=/home/neo/.ethereum/geth/ethash count=3 INFO [02-01|23:35:12] Disk storage enabled for ethash DAGs dir=/home/neo/.ethash count=2 INFO [02-01|23:35:12] Initialising Ethereum protocol versions="[63 62]" network=123456 INFO [02-01|23:35:12] Loaded most recent local header number=719 hash=61330b…82786e td=108754979 INFO [02-01|23:35:12] Loaded most recent local full block number=719 hash=61330b…82786e td=108754979 INFO [02-01|23:35:12] Loaded most recent local fast block number=719 hash=61330b…82786e td=108754979 INFO [02-01|23:35:12] Loaded local transaction journal transactions=0 dropped=0 INFO [02-01|23:35:12] Regenerated local transaction journal transactions=0 accounts=0 WARN [02-01|23:35:12] Blockchain not empty, fast sync disabled INFO [02-01|23:35:12] Starting P2P networking INFO [02-01|23:35:12] RLPx listener up self="enode://9f6490ffb5236f2ddc5710ae73d47c740e0a3644bbd2d67029cf4a6c4693d2f470b642fd2cc3507f7e851df60aaeb730a1270b7a477f91ec5b6b17a8a4b40527@[::]:30303?discport=0" INFO [02-01|23:35:12] IPC endpoint opened: /home/neo/.ethereum/geth.ipc INFO [02-01|23:35:12] HTTP endpoint opened: http://0.0.0.0:8545 INFO [02-01|23:35:15] Mapped network port proto=tcp extport=30303 intport=30303 interface="UPNP IGDv1-IP1" Web3j 将使用这个地址连接 HTTP endpoint opened: http://your_ip_address:8545
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>cn.netkiller</groupId> <artifactId>ethereum</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>ethereum</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.web3j</groupId> <artifactId>core</artifactId> <version>3.2.0</version> </dependency> </dependencies> </project>
boolean -> bool BigInteger -> uint/int byte[] -> bytes String -> string and address types List<> -> dynamic/static array
package cn.netkiller.ethereum; import java.io.IOException; import org.web3j.protocol.Web3j; import org.web3j.protocol.core.methods.response.Web3ClientVersion; import org.web3j.protocol.http.HttpService; public class Web3JClient { // TODO Auto-generated method stub public static void main(String[] args) { String url = "http://172.16.0.1:8545/"; Web3j web3j = Web3j.build(new HttpService(url)); // defaults to http://localhost:8545/ try { Web3ClientVersion web3ClientVersion = web3j.web3ClientVersion().send(); String clientVersion = web3ClientVersion.getWeb3ClientVersion(); System.out.println(clientVersion); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } 运行结果
Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9.1
除了 TCP 方式连接，还支持 IPC 方式。这种方式比较少用，可以使用 localhost 替代。
// OS X/Linux/Unix: Web3j web3 = Web3j.build(new UnixIpcService("/path/to/socketfile")); ... // Windows Web3j web3 = Web3j.build(new WindowsIpcService("/path/to/namedpipefile")); ... public List<String> getAccountlist() { try { return web3j.ethAccounts().send().getAccounts(); } catch (Exception e) { e.printStackTrace(); } return null; } public String getAccount(int index) { String account = null; try { account = web3j.ethAccounts().send().getAccounts().get(index); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return account; } Admin web3j = Admin.build(new HttpService()); // defaults to http://localhost:8545/ PersonalUnlockAccount personalUnlockAccount = web3j.personalUnlockAccount("0x000...", "a password").sendAsync().get(); if (personalUnlockAccount.accountUnlocked()) { // send a transaction } package cn.netkiller.ethereum.credentials; import java.io.IOException; import java.math.BigInteger; import org.web3j.crypto.Credentials; import org.web3j.crypto.ECKeyPair; import org.web3j.protocol.Web3j; import org.web3j.protocol.http.HttpService; public class CredentialsTest { public static void main(String[] args) { // TODO Auto-generated method stub String url = "http://172.16.0.1:8545/"; Web3j web3j = Web3j.build(new HttpService(url)); // defaults to http://localhost:8545/ try { String account = web3j.ethAccounts().send().getAccounts().get(0); Credentials credentials = Credentials.create(account); ECKeyPair keyPair = credentials.getEcKeyPair(); BigInteger privateKey = keyPair.getPrivateKey(); BigInteger publicKey = keyPair.getPublicKey(); System.out.println(privateKey); System.out.println("---"); System.out.println(publicKey); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public BigInteger getBalance(String account) throws IOException { EthGetBalance ethGetBalance = web3j.ethGetBalance(account, DefaultBlockParameterName.LATEST).send(); BigInteger balance = ethGetBalance.getBalance(); return balance; } public void transfer(String account, float coin) throws InterruptedException, IOException, TransactionException, Exception { String password = ""; String walletfile = "/Users/neo/netkiller/UTC--2018-01-20T04-04-06.786586541Z--83fda0ba7e6cfa8d7319d78fa0e6b753a2bcb5a6"; Credentials credentials = WalletUtils.loadCredentials(password, walletfile); TransactionReceipt transactionReceipt = Transfer .sendFunds(web3j, credentials, account, BigDecimal.valueOf(coin), Unit.ETHER).send(); System.out.println(transactionReceipt.getStatus()); } EthTransaction transaction = web3.ethGetTransactionByHash("TRANSACTION_HASH") .sendAsync().get(); System.out.println(transaction.getResult()); package cn.netkiller.ethereum.wallet; import java.io.File; import java.io.IOException; import java.security.InvalidAlgorithmParameterException; import java.security.NoSuchAlgorithmException; import java.security.NoSuchProviderException; import org.web3j.crypto.CipherException; import org.web3j.crypto.WalletUtils; public class WalletMain { public void createWallet() throws NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException, CipherException, IOException { File file = new File("/tmp/ethereum/keystore"); String password = "passw0rd"; String fileName = WalletUtils.generateFullNewWalletFile(password, file); System.out.println(fileName); } public static void main(String[] args) { // TODO Auto-generated method stub WalletMain wallet = new WalletMain(); try { wallet.createWallet(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } 运行结果
neo@MacBook-Pro ~ % mkdir -p /tmp/ethereum/keystore neo@MacBook-Pro ~ % ll /tmp/ethereum/keystore total 8 -rw-r--r-- 1 neo wheel 491B Feb 4 18:30 UTC--2018-02-04T10-30-58.476000000Z--75d01e920d6e018445dae504058ce4d968fd2a58.json neo@MacBook-Pro ~ % cat /tmp/ethereum/keystore/UTC--2018-02-04T10-30-58.476000000Z--75d01e920d6e018445dae504058ce4d968fd2a58.json {"address":"75d01e920d6e018445dae504058ce4d968fd2a58","id":"80700448-69bc-475a-aaf9-f2b836f17b13","version":3,"crypto":{"cipher":"aes-128-ctr","ciphertext":"fe86f5dbd61d15d092f9d6870e70bff7ed99a7925703ea71eef23669c8e3ec62","cipherparams":{"iv":"d058819ab660cd062080b405591ba143"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":262144,"p":1,"r":8,"salt":"f69c535137b08667dbac53b8001313f5b43f81fce67a5d0e94b518c97d212d14"},"mac":"c247e34760bc838c3a4c8b2da286ccc6acec244bbc13fc6cc9ce28e88a7319d5"}} package cn.netkiller.ethereum.wallet; import java.io.File; import java.io.IOException; import java.security.InvalidAlgorithmParameterException; import java.security.NoSuchAlgorithmException; import java.security.NoSuchProviderException; import org.web3j.crypto.CipherException; import org.web3j.crypto.Credentials; import org.web3j.crypto.WalletUtils; public class WalletMain { public void walletAddress() throws IOException, CipherException { File file = new File( "/tmp/ethereum/keystore/UTC--2018-02-04T10-43-27.339000000Z--7cab470df532710d13078c5cdc0812a27f70cf51.json"); String password = "passw0rd"; Credentials credentials = WalletUtils.loadCredentials(password, file); System.out.println(credentials.getAddress()); } public static void main(String[] args) { // TODO Auto-generated method stub WalletMain wallet = new WalletMain(); try { wallet.walletAddress(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } 运行结果
0x7cab470df532710d13078c5cdc0812a27f70cf51
neo@netkiller ~/ethereum/solidity % cat netkiller.sol pragma solidity ^0.4.18; contract Netkiller { string name; int num; function Netkiller() public{ name = "default"; num = 1; } function setName(string _name) public{ name = _name; } function getName() public view returns(string){ return name; } function setNum(int n) public{ num = n; } function addNum(int m) public view returns(int res){ res = m + num; } } 编译智能合约
$ solc /path/to/<smart-contract>.sol --bin --abi --optimize -o output/ $ web3j solidity generate /path/to/<smart-contract>.bin /path/to/<smart-contract>.abi -o /path/to/src/main/java -p com.your.organisation.name
$ solc netkiller.sol --bin --abi --optimize -o output/ $ web3j solidity generate output/Netkiller.bin output/Netkiller.abi -p cn.netkiller.ethereum.contract -o java _ _____ _ _ | | |____ (_) (_) __ _____| |__ / /_ _ ___ \ \ /\ / / _ \ '_ \ \ \ | | | / _ \ \ V V / __/ |_) |.___/ / | _ | || (_) | \_/\_/ \___|_.__/ \____/| |(_)|_| \___/ _/ | |__/ Generating cn.netkiller.ethereum.contract.Netkiller ... File written to java neo@netkiller ~/ethereum/solidity % ll java/cn/netkiller/ethereum/contract/Netkiller.java -rw-rw-r-- 1 neo neo 5.9K Feb 3 23:02 java/cn/netkiller/ethereum/contract/Netkiller.java
启动以太坊，并开始挖矿。注意参数 --mine --minerthreads 1 ，你也可以启动后在JavaScript 控制台钟启动挖矿。
neo@netkiller ~ % geth --networkid 123456 --rpc --rpcaddr="0.0.0.0" --rpccorsdomain "*" --mine --minerthreads 1
package cn.netkiller.ethereum; import java.math.BigInteger; import org.web3j.crypto.Credentials; import org.web3j.crypto.WalletUtils; import org.web3j.protocol.Web3j; import org.web3j.protocol.http.HttpService; import org.web3j.tx.Contract; import org.web3j.tx.ManagedTransaction; import cn.netkiller.ethereum.contract.Netkiller; public class ContractTest { public static void main(String[] args) throws Exception { // TODO Auto-generated method stub String walletfile = "/Users/neo/Downloads/UTC--2018-01-20T04-04-06.786586541Z--83fda0ba7e6cfa8d7319d78fa0e6b753a2bcb5a6"; Web3j web3j = Web3j.build(new HttpService("http://172.16.0.1:8545")); Credentials credentials = WalletUtils.loadCredentials("", walletfile); Netkiller contract = Netkiller.deploy(web3j, credentials, ManagedTransaction.GAS_PRICE, Contract.GAS_LIMIT).send(); System.out.println(contract.isValid()); if (contract.isValid()) { System.out.println("---"); String contractAddress = contract.getContractAddress(); System.out.println(contractAddress); System.out.println("---"); String result = contract.getName().send(); System.out.println(result); contract.setName("Netkiller").send(); System.out.println(contract.getName().send()); System.out.println("---"); contract.setNum(BigInteger.valueOf(8)).send(); System.out.println(contract.addNum(BigInteger.valueOf(8)).send()); System.out.println("---"); } else { System.out.println("Deploy ERROR !!!"); } } } 运行结果
true --- 0xef872f1b344a4b7c765c7d765a3cc82b741777a9 --- default Netkiller --- 16 ---
在程序运行是，去看 geth 打印的日志，有如下记录打印
INFO [02-04|00:04:43] Submitted transaction fullhash=0x9f70ccb600294d2dd6dda08d090362131b107d42a692f27dd4a3b7548dbaf22c recipient=0xEF872F1b344a4B7C765c7D765a3cC82b741777a9
HelloWorld contract = HelloWorld.load(contractAddress,web3j,credentials, ManagedTransaction.GAS_PRICE, Contract.GAS_LIMIT);
文档地址 http://web3py.readthedocs.io/
本文发表于2018年02月04日 22:37
(c)注：本文转载自https://my.oschina.net/neochen/blog/1618287，转载目的在于传递更多信息，并不代表本网赞同其观点和对其真实性负责。如有侵权行为，请联系我们，我们会及时删除.
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