SJTU-EE357-project-BlockChain

SJTU-EE357计算机网络课程大作业，实现简单的智能合约应用

Introduction

区块链智能合约技术

a)研究导向：智能合约是区块链最为吸引商业界广泛关注的一个发展方向，请参考相关 资料，搭建公链或联盟链平台，部署并运行智能合约，了解智能合约的发展趋势。

*b) 工程导向：智能合约可自动在区块链上执行，但其应用并不局限于处理交易。目前， 智能合约也被用于实现安全多方计算、实现简单的区块链小游戏等方向。请基于以太坊或联盟链平台，编写智能合约，并利用该智能合约实现除处理交易以外的功能（例如：简单的智能合约小游戏）。

联盟链的搭建可参考： https://hyperledger-fabric.readthedocs.io/en/release-1.4/whatis.html ；

智能合约的相关研究可参考 https://github.com/decrypto-org/blockchain-papers#general ；

以太坊的使用请参考：https://ethereum.org/ ；

Configuration

• 18.04.2-Ubuntu x86_64 GNU/Linux
• node.js v12.17.0
• npm 6.14.4
• truffle v5.1.28

Issue

truffle init
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
✔ Preparing to download box
✖ Downloading
Unbox failed!
✖ Downloading
Unbox failed!
RequestError: Error: connect ECONNREFUSED 0.0.0.0:443
......

raw.githubusercontent.com 域名污染,see: https://bbs.huaweicloud.com/blogs/143682

    PlayerStateListener = await App.monopoly.events.PlayerChange(function (error, event) {
        console.log(event);
    })
        .on('data', function (event) {
            App.updatePlayerInfo();
        })
        .on('error', console.error);
>>>>>>>>>>>>>>>>>>>>>>>>>>
This has no response in browser

Web3.providers.HttpProvider => Web3.providers.WebsocketProvider ;

>>>>>>>>>>>>>>>>>>>>>>>>>>
this.monopoly is null.

use keyword: await / async ;

Develop

1.启动环境

truffle develop

2.运行(in another shell)

truffle migrate
cd app | npm run dev

3. 打开 localhost:8080

Solodity API

function goBankrupt(uint32 _roomId, uint player_turn) public view return {
	// all grid belong to this player iturns free;
	emit BankRupt(_roomId, , his platyer_turn,his address , his money(minus), current left player num)
}

function move(uint32 _roomId, uint player_turn) public view return {
    assert player_turn == room player turn
    random move
    pay tax (if gridtype = 1)
    check breakup (if gridtype = 1)
    check affordable -> buy (if gridtype = 1 and level < 3)
    if not buy
        find next turn and change room player turn(skip bankrupted one)
	    emit OneStep(_roomId, move_step_len, next_player_turn)
	if buy
	    emit BuyGrid(_roomId, move_step_len, cost, player_turn, player_position)
}

function buy(uint32 _roomId, uint player_turn) public view return {
    assert player_turn == room player turn
    - money
    set grid

    find next turn and change room player turn(skip bankrupted one)
	emit OneStep(_roomId, 0, next_player_turn)

}