4. 智能合约开发规范¶
使用 Truffle 为区块链平台开发与使用 Truffle 为以太坊网络开发相同。Truffle 支持 Besu，唯一的区别是 Besu 不支持私钥管理。要将 Besu 与 Truffle 一起使用，必须配置一个 Truffle 钱包。
4.2. 安装Truffle钱包¶
npm install --save @truffle/hdwallet-provider
笔记
使用 Truffle 5，您必须使用支持 Web3 1.0 的钱包，否则 Truffle 任务会挂起。
4.3. 更新Truffle配置文件¶
要添加钱包提供程序，请更新truffle-config.js项目目录中的文件。代替：
- JSON-RPC-http-endpoint: 使用 Besu 节点的 JSON-RPC 端点（IP 地址和端口）。
- account-private-key: 使用包含 Ether 的 Ethereum 帐户的私钥。
const PrivateKeyProvider = require("@truffle/hdwallet-provider");
const privateKey = "<account-private-key>";
const privateKeyProvider = new PrivateKeyProvider(privateKey, "<JSON-RPC-http-endpoint>");
module.exports = {
// See <http://truffleframework.com/docs/advanced/configuration>
// for more about customizing your Truffle configuration!
networks: {
besuWallet: {
provider: privateKeyProvider,
network_id: "*"
},
}
};
4.4. 编写合约¶
使用Truffle¶
step1: 创建项目目录¶
mkdir ticket-dapp && cd ticket-dapp/
step2: 项目初始化¶
truffle init
step3: 创建合约¶
cd contracts/
touch contracts/NFT.sol && vim NFT.sol
result:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
pragma solidity ^0.8.1;
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract TicketNFT is ERC721, Ownable {
...
}
使用Remix¶
在项目根目录下的contracts/下创建合约文件, 例如: NFT.sol, 然后编辑:
pragma solidity ^0.8.1;
import 'https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/ERC721.sol';
import 'https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.sol';
contract NFT is ERC721, Ownable {
using Strings for uint256;
// Optional mapping for token URIs
mapping (uint256 => string) private _tokenURIs;
// Base URI
string private _baseURIextended;
constructor(string memory _name, string memory _symbol) ERC721(_name, _symbol) {}
function setBaseURI(string memory baseURI_) external onlyOwner() {
_baseURIextended = baseURI_;
}
function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
function _baseURI() internal view virtual override returns (string memory) {
return _baseURIextended;
}
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
string memory base = _baseURI();
// If there is no base URI, return the token URI.
if (bytes(base).length == 0) {
return _tokenURI;
}
// If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
if (bytes(_tokenURI).length > 0) {
return string(abi.encodePacked(base, _tokenURI));
}
// If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
return string(abi.encodePacked(base, tokenId.toString()));
}
function mint(address _to, uint256 _tokenId, string memory image_url) external onlyOwner() {
_mint(_to, _tokenId);
_setTokenURI(_tokenId, image_url);
}
}
4.5. 部署合约¶
使用Truffle¶
truffle migrate --network besuWallet
result:
Compiling your contracts...
===========================
> Everything is up to date, there is nothing to compile.
Starting migrations...
======================
> Network name: 'besuWallet'
> Network id: 1337
> Block gas limit: 4700000 (0x47b760)
1_initial_migration.js
======================
Deploying 'Migrations'
----------------------
> transaction hash: 0x834ad971e6cbe802ba33e4449d2867740541f9e1e7a2f7529dfbdf73f3ad8fdd
> Blocks: 0 Seconds: 12
> contract address: 0x38cF23C52Bb4B13F051Aec09580a2dE845a7FA35
> block number: 375744
> block timestamp: 1650534867
> account: 0x627306090abaB3A6e1400e9345bC60c78a8BEf57
> balance: 90000
> gas used: 248854 (0x3cc16)
> gas price: 0 gwei
> value sent: 0 ETH
> total cost: 0 ETH
> Saving migration to chain.
> Saving artifacts
-------------------------------------
> Total cost: 0 ETH
Summary
=======
> Total deployments: 1
> Final cost: 0 ETH