uniapp开发DAPP钱包应用(二) Vue + Java

本文主要是介绍uniapp开发DAPP钱包应用(二) Vue + Java，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

上一节我们讲了如何通过vue uniapp还有web3以及需要准备的相关组件，来搭建了DAPP开发的环境。

这一节，我们来说说如何用代码来实现DAPP相关接口。

1. ethers实现类 

导入组件

import { ethers , providers , utils  } from "ethers";
import tokenABI from '@/utils/tokenABI.json'
export class MetaEthers {}

初始化

static #provider = null ;
static #account = null ;
static #message = 'sign message'
static #max = '0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff'
constructor(){check();if(!MetaEthers.#provider)MetaEthers.#provider = new ethers.providers.Web3Provider(window.ethereum);
} 
function check(target){if(typeof window.ethereum == 'undefined')throw uni.showToast({title: "MetaMask is unInstalled!", icon: "none"})
}

获取钱包地址

// 获取钱包地址async setAccounts(){let account = await MetaEthers.#provider.send("eth_requestAccounts", []);MetaEthers.#account =  account instanceof Array ? account[0] : account;let info = JSON.parse(localStorage.getItem('userinfo'))if( info && MetaEthers.#account.toLowerCase() !== info.chain_address){this.destory()throw t('dismacth');} else{return MetaEthers.#account;}     }

签名获取

// 签名
async sign(){if(!MetaEthers.#account) throw { reason: t('wallet_warning'), errType: -1 }const signer = MetaEthers.#provider.getSigner();let signature = await signer.signMessage(MetaEthers.#message)console.log( utils.verifyMessage(MetaEthers.#message, signature).toLowerCase() )return signature;
}

余额获取

// 钱包余额
async getWallet(){if(!MetaEthers.#account) throw { reason: t('wallet_warning'), errType: -1 }let Contract = new ethers.Contract(tokenAddress,tokenABI,MetaEthers.#provider.getSigner());let value = await Contract.balanceOf(MetaEthers.#account);return ethers.utils.formatUnits(value, 18)
}

2. 实现签名登录

import {MetaEthers
} from '@/utils/metamask.js'let MetaWallet = {destory: () => {}
};// 通过实现类，获取地址及签名，后端进行验证
let chain_address = await MetaWallet.setAccounts();
let signature = await MetaWallet.sign();
const {data,code
} = await walletLogin({method: "POST",query: {chain_address,message: MetaEthers.getMessage(),signature,},
});

后端实现

/*** <b>功能描述：</b>验签<br>* <b>修订记录：</b><br>*/
public static Boolean isSignatureValid(final String address, final String signature, final String message) {log.info("isSignatureValid invoked for Address {} with Signature {} and Message {} ", address, signature, message);final String personalMessagePrefix = "\u0019Ethereum Signed Message:\n";boolean match = false;final String prefix = personalMessagePrefix + message.length();final byte[] msgHash = Hash.sha3((prefix + message).getBytes());final byte[] signatureBytes = Numeric.hexStringToByteArray(signature);byte v = signatureBytes[64];if (v < 27) {v += 27;}final Sign.SignatureData sd = new Sign.SignatureData(v,Arrays.copyOfRange(signatureBytes, 0, 32),Arrays.copyOfRange(signatureBytes, 32, 64));String addressRecovered = null;// Iterate for each possible key to recoverfor (int i = 0; i < 4; i++) {final BigInteger publicKey = Sign.recoverFromSignature((byte) i, new ECDSASignature(new BigInteger(1, sd.getR()),new BigInteger(1, sd.getS())), msgHash);if (publicKey != null) {addressRecovered = "0x" + Keys.getAddress(publicKey);if (addressRecovered.equalsIgnoreCase(address)) {match = true;break;}}}return match;
}

当验签成功后，即实现登录，接下来基本都业务相关代码，自行开发吧！！！

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