本文共 9494 字，大约阅读时间需要 31 分钟。

作者：Key

运行环境:FISCO BCOS联盟链中间件——WeBASE-Front

Roles.sol

pragma solidity^0.4.25;library Roles{       struct Role{           mapping(address=>bool) bearer;    }    //判定地址存在否    function has(Role storage role,address amount)internal view returns(bool){           require(amount!=address(0));        return role.bearer[amount];    }    //添加角色    function add(Role storage role,address amount)internal{           require(!has(role,amount));        role.bearer[amount] = true;    }    //删除角色    function remove(Role storage role,address amount)internal{           require(has(role,amount));        role.bearer[amount] = false;    }}

Producer.sol

pragma solidity^0.4.25;import "Roles.sol";contract Producer{       using Roles for Roles.Role;    Roles.Role private _producer;        event producerAdded(address amount);    event producerRemoved(address amount);        constructor(address producer)public{           _addProducer(producer);    }        function _addProducer(address amount)internal{           _producer.add(amount);        emit producerAdded(amount);    }        function _removeProducer(address amount)internal{           _producer.remove(amount);        emit producerAdded(amount);    }        function isProducer(address amount)public view returns(bool){           return _producer.has(amount);    }    modifier onlyProducer(){           require(isProducer(msg.sender));        _;    }    function addProducer(address amount)public onlyProducer{           _addProducer(amount);    }        function removeProducer()public{           _removeProducer(msg.sender);    }}

Distributor.sol

pragma solidity^0.4.25;import "Roles.sol";contract Distributor{       using Roles for Roles.Role;    Roles.Role private _distributor;        event distributorAdded(address amount);    event distributorRemoved(address amount);        constructor(address distributor)public{           _addDistributor(distributor);    }        function _addDistributor(address amount)internal{           _distributor.add(amount);        emit distributorAdded(amount);    }        function _removeDistributor(address amount)internal{           _distributor.remove(amount);        emit distributorAdded(amount);    }        function isDistributor(address amount)public view returns(bool){           return _distributor.has(amount);    }    modifier onlyDistributor(){           require(isDistributor(msg.sender));        _;    }    function addDistributor(address amount)public onlyDistributor{           _addDistributor(amount);    }        function removeDistributor() public{           _removeDistributor(msg.sender);    }}

Retailer.sol

pragma solidity^0.4.25;import "Roles.sol";contract Retailer{       using Roles for Roles.Role;    Roles.Role private _retailer;        event retailerAdded(address amount);    event retailerRemoved(address amount);        constructor(address distributor)public{           _addRetailer(distributor);    }        function _addRetailer(address amount)internal{           _retailer.add(amount);        emit retailerAdded(amount);    }        function _removeRetailer(address amount)internal{           _retailer.remove(amount);        emit retailerAdded(amount);    }        function isRetailer(address amount)public view returns(bool){           return _retailer.has(amount);    }    modifier onlyRetailer(){           require(isRetailer(msg.sender));        _;    }    function addRetailer(address amount)public onlyRetailer{           _addRetailer(amount);    }        function removeRetailer()public{           _removeRetailer(msg.sender);    }}

FoodInfoItem.sol

pragma solidity^0.4.25;contract FoodInfoItem{       uint256[] _timestamp;  //时间戳    string[] _traceName;   //交易名称    address[] _traceAddress; //交易地址    uint8[] _traceQuality;   //交易食品质量    string _name;           //食品名称    string _currentName;    //当前交易名称    address _currentAddress; //当前交易地址    uint8 _currentQuality;   //当前交易质量 0 优质 1 合格 2 不合格    uint8 _status;          //当前交易状态 0生产 1 分销 2销售    address owner;        constructor(string name,string traceName,address traceAddress,uint8 quality)public{           _timestamp.push(now);        _traceName.push(traceName);        _traceAddress.push(traceAddress);        _traceQuality.push(quality);        _name = name;        _currentName = traceName;        _currentAddress = traceAddress;        _currentQuality = quality;        _status = 0;        owner = msg.sender;    }    function addFoodByDistributor(string traceName,address traceAddress,uint8 quality)public returns(bool){           require(_status == 0,"this is not already exit");        _timestamp.push(now);        _traceName.push(traceName);        _traceAddress.push(traceAddress);        _traceQuality.push(quality);        _currentName = traceName;        _currentAddress = traceAddress;        _currentQuality = quality;        _status = 1;        return true;    }        function addFoodByRetailer(string traceName,address traceAddress,uint8 quality)public returns(bool){           require(_status == 1,"this is not already exit");        _timestamp.push(now);        _traceName.push(traceName);        _traceAddress.push(traceAddress);        _traceQuality.push(quality);        _currentName = traceName;        _currentAddress = traceAddress;        _currentQuality = quality;        _status = 2;        return true;    }        function getFoodInfo()public view returns(uint256,string,string,uint8,address,uint8){           return(_timestamp[0],_name,_currentName,_currentQuality,_traceAddress[0],_status);    }        function getFoodInfoByNew()public view returns(uint256,string,string,address,uint8){           return(_timestamp[0],_name,_traceName[0],_traceAddress[0],_traceQuality[0]);    }        function getDFoodInfoByDistributor()public view returns(uint256,string,string,string,address,uint8){           return(_timestamp[0],_name,_traceName[0],_traceName[1],_traceAddress[1],_traceQuality[1]);    }        function getFoodInfoByRetailer()public view returns(uint256,string,string,string,string,address,uint8){           return(_timestamp[0],_name,_traceName[0],_traceName[1],_traceName[2],_traceAddress[2],_traceQuality[2]);    }            function getFoodInfoByRoles()public view returns(uint256[],address[],uint8[]){           return(_timestamp,_traceAddress,_traceQuality);    }        function getFoodInfoByAll()public view returns(string,uint256,string,uint8,uint256,string,uint8,uint256,string,uint8){           return(_name,_timestamp[0],_traceName[0],_traceQuality[0],_timestamp[1],_traceName[1],_traceQuality[1],_timestamp[2],_traceName[2],_traceQuality[2]);    }}

Trace.sol

pragma solidity^0.4.25;//pragma experimental ABIEncoderV2; //返回结构体类型import "./Roles.sol";import "./Producer.sol";import "./Distributor.sol";import "./Retailer.sol";import "./FoodInfoItem.sol";contract Trace is Producer,Distributor,Retailer{       mapping(uint256=>address) foods;   //溯源码映射食品合约地址    uint256[] foodList;     address owner; //合约的部署者，管理员        //初始化三个角色，农场，分销商，超市    constructor(address producer,address distributor,address retailer)public Producer(producer) Distributor(distributor) Retailer(retailer){           owner = msg.sender;    }    //农村食品上链    function newFood(uint256 traceNumber,string name,string traceName,uint8 quality)public onlyProducer returns(address){           require(foods[traceNumber]==address(0));        FoodInfoItem food = new FoodInfoItem(name,traceName,msg.sender,quality);        foods[traceNumber] = food;        foodList.push(traceNumber);        return food;    }    //分销商食品上链    function addFoodByDistributor(uint256 traceNumber,string traceName,uint8 quality)public onlyDistributor returns(bool){           require(foods[traceNumber]!=address(0));        return FoodInfoItem(foods[traceNumber]).addFoodByDistributor(traceName,msg.sender,quality);    }    //超市食品上链    function addFoodByRetailer(uint256 traceNumber,string traceName,uint8 quality)public onlyRetailer returns(bool){           require(foods[traceNumber]!=address(0));        return FoodInfoItem(foods[traceNumber]).addFoodByRetailer(traceName,msg.sender,quality);    }    //当前食品溯源    function getFoodInfo(uint256 traceNumber)public view returns(uint256,string,string,uint8,address,uint8){           return FoodInfoItem(foods[traceNumber]).getFoodInfo();    }    //农场溯源    function getFoodInfoByNew(uint256 traceNumber)public view returns(uint256,string,string,address,uint8){           return FoodInfoItem(foods[traceNumber]).getFoodInfoByNew();    }    //分销商溯源    function getDFoodInfoByDistributor(uint256 traceNumber)public view returns(uint256,string,string,string,address,uint8){           return FoodInfoItem(foods[traceNumber]).getDFoodInfoByDistributor();    }    //超市溯源    function getFoodInfoByRetailer(uint256 traceNumber)public view returns(uint256,string,string,string,string,address,uint8){           return FoodInfoItem(foods[traceNumber]).getFoodInfoByRetailer();    }    //三个阶段溯源    function getFoodInfoByRoles(uint256 traceNumber)public view returns(uint256[],address[],uint8[]){           return FoodInfoItem(foods[traceNumber]).getFoodInfoByRoles();    }    //消费者整体溯源    function getFoodInfoByAll(uint256 traceNumber)public view returns(string,uint256,string,uint8,uint256,string,uint8,uint256,string,uint8){           return FoodInfoItem(foods[traceNumber]).getFoodInfoByAll();    }    //获取所有食品    function getFoodList()public view returns(uint256[]){           require(msg.sender == owner,'you are not owner');        return foodList;    }}

最终效果图：