HyperLeger Fabric开发（十）——资产交易平台实战

HyperLeger Fabric开发（十）--资产交易平台实战

一、资产交易平台需求分析

1、资产交易平台的功能

A、用户开户、销户功能
B、资产登记，即资产上链，资产绑定到用户
C、资产转让，即资产所有权的变更
D、查询功能，包括用户查询、资产查询、资产历史变更查询

2、业务实体

A、用户，属性包括名字、标识、资产列表、
B、资产，属性包括名字、标识、特殊属性列表
C、资产变更记录，属性包括资产标识、资产源所有者、资产变更后所有者

3、交互方法

A、用户注册，参数包括用户名称、用户标识
B、销户，参数包括用户标识
C、资产登记，参数包括资产名称、资产标识、特殊属性列表、资产所有者
D、资产转让，参数包括资产所有者、资产标识、资产受让者
E、用户查询，参数包括用户标识，返回用户实体
F、资产查询，参数包括资产标识，返回资产实体
G、资产变更记录，参数包括资产标识，记录类型（登记/转让/全部），返回资产变更记录列表。

二、链码开发

1、链码编写

链码需要定义资产交易平台定义的所有实体和交互方法，然后在Invoke接口中调用相应的交互方法。
在Fabric工程目录AssetExchange/chaincode/assetexchange目录下进行链码开发，链码AssetExchangeChainCode.go实现如下：

package mainimport (   "fmt"   "encoding/json"   "github.com/hyperledger/fabric/core/chaincode/shim"   "github.com/hyperledger/fabric/protos/peer")// 用户type User struct {   Name string `json:"name"`   ID string `json:"id"`   Assets []string `json:"assets"`}// 资产type Asset struct {   Name string `json:"name"`   ID string `json:"id"`   Metadata string `json:"metadata"`}// 资产变更记录type AssetHistory struct {   AssetID string `json:"asset_id"`   OriginOwnerID string `json:"origin_owner_id"`   CurrentOwnerID string `json:"current_owner_id"`}// 原始用户占位符const (   originOwner = "originOwnerPlaceholder")func constructUserKey(userId string)string{   return fmt.Sprint("user_%s",userId)}func constructAssetKey(assetID string)string{   return fmt.Sprint("asset_%s",assetID)}// 用户注册（开户）func userRegister(stub shim.ChaincodeStubInterface, args []string) peer.Response{   // step 1:检查参数个数   if len(args) != 2{      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   name := args[0]   id := args[1]   if name == "" || id == ""{      return shim.Error("Invalid args")   }   // step 3:验证数据是否存在   if userBytes, err := stub.GetState(constructUserKey(id));err != nil || len(userBytes) != 0{      return shim.Error("User alreay exist")   }   // step 4: 写入状态   user := User{      Name:name,      ID:id,      Assets:make([]string,0),   }   // 序列化对象   userBytes, err := json.Marshal(user)   if err != nil{      return shim.Error(fmt.Sprint("marshal user error %s",err))   }   err = stub.PutState(constructUserKey(id), userBytes)   if err != nil {      return shim.Error(fmt.Sprint("put user error %s", err))   }   return shim.Success(nil)}// 用户注销func userDestroy(stub shim.ChaincodeStubInterface,args []string)peer.Response{   // step 1:检查参数个数   if len(args) != 1{      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   id := args[0]   if id == ""{      return shim.Error("Invalid args")   }   // step 3:验证数据是否存在   userBytes, err := stub.GetState(constructUserKey(id));   if err != nil || len(userBytes) == 0{      return shim.Error("User not found")   }   // step 4: 写入状态   if err := stub.DelState(constructUserKey(id)); err != nil {      return shim.Error(fmt.Sprintf("delete user error: %s", err))   }   // 删除用户名下的资产   user := new(User)   err = json.Unmarshal(userBytes,user)   if err != nil{      return shim.Error(fmt.Sprintf("unmarshal user error: %s", err))   }   for _,assetId := range user.Assets{      if err := stub.DelState(constructAssetKey(assetId)); err != nil {         return shim.Error(fmt.Sprintf("delete asset error: %s", err))      }   }   return shim.Success(nil)}// 资产登记func assetEnroll(stub shim.ChaincodeStubInterface,args []string)peer.Response{   // step 1:检查参数个数   if len(args) != 4 {      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   assetName := args[0]   assetId := args[1]   metadata := args[2]   ownerId := args[3]   if assetName == "" || assetId == "" || ownerId == ""{      return shim.Error("Invalid args")   }   // step 3:验证数据是否存在   userBytes, err := stub.GetState(constructUserKey(ownerId))   if err != nil || len(userBytes) == 0{      return shim.Error("User not found")   }   if assetBytes, err := stub.GetState(constructAssetKey(assetId)); err == nil && len(assetBytes) != 0 {      return shim.Error("Asset already exist")   }   // step 4: 写入状态   asset := &Asset{      Name:     assetName,      ID:       assetId,      Metadata: metadata,   }   assetBytes, err := json.Marshal(asset)   if err != nil {      return shim.Error(fmt.Sprintf("marshal asset error: %s", err))   }   if err := stub.PutState(constructAssetKey(assetId), assetBytes); err != nil {      return shim.Error(fmt.Sprintf("save asset error: %s", err))   }   user := new(User)   // 反序列化user   if err := json.Unmarshal(userBytes, user); err != nil {      return shim.Error(fmt.Sprintf("unmarshal user error: %s", err))   }   user.Assets = append(user.Assets, assetId)   // 序列化user   userBytes, err = json.Marshal(user)   if err != nil {      return shim.Error(fmt.Sprintf("marshal user error: %s", err))   }   if err := stub.PutState(constructUserKey(user.ID), userBytes); err != nil {      return shim.Error(fmt.Sprintf("update user error: %s", err))   }   // 资产变更历史   history := &AssetHistory{      AssetID:        assetId,      OriginOwnerID:  originOwner,      CurrentOwnerID: ownerId,   }   historyBytes, err := json.Marshal(history)   if err != nil {      return shim.Error(fmt.Sprintf("marshal assert history error: %s", err))   }   historyKey, err := stub.CreateCompositeKey("history", []string{      assetId,      originOwner,      ownerId,   })   if err != nil {      return shim.Error(fmt.Sprintf("create key error: %s", err))   }   if err := stub.PutState(historyKey, historyBytes); err != nil {      return shim.Error(fmt.Sprintf("save assert history error: %s", err))   }   return shim.Success(historyBytes)}// 资产转让func assetExchange(stub shim.ChaincodeStubInterface,args []string)peer.Response{   // step 1:检查参数个数   if len(args) != 3 {      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   ownerID := args[0]   assetID := args[1]   currentOwnerID := args[2]   if ownerID == "" || assetID == "" || currentOwnerID == ""{      return shim.Error("Invalid args")   }   // step 3:验证数据是否存在   originOwnerBytes, err := stub.GetState(constructUserKey(ownerID))   if err != nil || len(originOwnerBytes) == 0 {      return shim.Error("user not found")   }   currentOwnerBytes, err := stub.GetState(constructUserKey(currentOwnerID))   if err != nil || len(currentOwnerBytes) == 0 {      return shim.Error("user not found")   }   assetBytes, err := stub.GetState(constructAssetKey(assetID))   if err != nil || len(assetBytes) == 0 {      return shim.Error("asset not found")   }   // 校验原始拥有者确实拥有当前变更的资产   originOwner := new(User)   // 反序列化user   if err := json.Unmarshal(originOwnerBytes, originOwner); err != nil {      return shim.Error(fmt.Sprintf("unmarshal user error: %s", err))   }   aidexist := false   for _, aid := range originOwner.Assets {      if aid == assetID {         aidexist = true         break      }   }   if !aidexist {      return shim.Error("asset owner not match")   }   // step 4: 写入状态   assetIds := make([]string, 0)   for _, aid := range originOwner.Assets {      if aid == assetID {         continue      }      assetIds = append(assetIds, aid)   }   originOwner.Assets = assetIds   originOwnerBytes, err = json.Marshal(originOwner)   if err != nil {      return shim.Error(fmt.Sprintf("marshal user error: %s", err))   }   if err := stub.PutState(constructUserKey(ownerID), originOwnerBytes); err != nil {      return shim.Error(fmt.Sprintf("update user error: %s", err))   }   // 当前拥有者插入资产id   currentOwner := new(User)   // 反序列化user   if err := json.Unmarshal(currentOwnerBytes, currentOwner); err != nil {      return shim.Error(fmt.Sprintf("unmarshal user error: %s", err))   }   currentOwner.Assets = append(currentOwner.Assets, assetID)   currentOwnerBytes, err = json.Marshal(currentOwner)   if err != nil {      return shim.Error(fmt.Sprintf("marshal user error: %s", err))   }   if err := stub.PutState(constructUserKey(currentOwnerID), currentOwnerBytes); err != nil {      return shim.Error(fmt.Sprintf("update user error: %s", err))   }   // 插入资产变更记录   history := &AssetHistory{      AssetID:        assetID,      OriginOwnerID:  ownerID,      CurrentOwnerID: currentOwnerID,   }   historyBytes, err := json.Marshal(history)   if err != nil {      return shim.Error(fmt.Sprintf("marshal asset history error: %s", err))   }   historyKey, err := stub.CreateCompositeKey("history", []string{      assetID,      ownerID,      currentOwnerID,   })   if err != nil {      return shim.Error(fmt.Sprintf("create key error: %s", err))   }   if err := stub.PutState(historyKey, historyBytes); err != nil {      return shim.Error(fmt.Sprintf("save asset history error: %s", err))   }   return shim.Success(nil)}// 用户查询func queryUser(stub shim.ChaincodeStubInterface,args []string)peer.Response{   // step 1:检查参数个数   if len(args) != 1 {      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   userID := args[0]   if userID == ""{      return shim.Error("Invalid args")   }   // step 3:验证数据是否存在   userBytes, err := stub.GetState(constructUserKey(userID))   if err != nil || len(userBytes) == 0 {      return shim.Error("user not found")   }   return shim.Success(userBytes)}// 资产查询func queryAsset(stub shim.ChaincodeStubInterface,args []string)peer.Response{   // step 1:检查参数个数   if len(args) != 1 {      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   assetID := args[0]   if assetID == ""{      return shim.Error("Invalid args")   }   // step 3:验证数据是否存在   assetBytes, err := stub.GetState(constructAssetKey(assetID))   if err != nil || len(assetBytes) == 0 {      return shim.Error("asset not found")   }   return shim.Success(assetBytes)}// 资产交易记录查询func queryAssetHistory(stub shim.ChaincodeStubInterface,args []string)peer.Response{   // step 1:检查参数个数   if len(args) != 2 && len(args) != 1 {      return shim.Error("Not enough args")   }   // step 2:验证参数正确性   assetID := args[0]   if assetID == ""{      return shim.Error("Invalid args")   }   queryType := "all"   if len(args) == 2 {      queryType = args[1]   }   if queryType != "all" && queryType != "enroll" && queryType != "exchange" {      return shim.Error(fmt.Sprintf("queryType unknown %s", queryType))   }   // step 3:验证数据是否存在   assetBytes, err := stub.GetState(constructAssetKey(assetID))   if err != nil || len(assetBytes) == 0 {      return shim.Error("asset not found")   }   // 查询相关数据   keys := make([]string, 0)   keys = append(keys, assetID)   switch queryType {   case "enroll":      keys = append(keys, originOwner)   case "exchange", "all": // 不添加任何附件key   default:      return shim.Error(fmt.Sprintf("unsupport queryType: %s", queryType))   }   result, err := stub.GetStateByPartialCompositeKey("history", keys)   if err != nil {      return shim.Error(fmt.Sprintf("query history error: %s", err))   }   defer result.Close()   histories := make([]*AssetHistory, 0)   for result.HasNext() {      historyVal, err := result.Next()      if err != nil {         return shim.Error(fmt.Sprintf("query error: %s", err))      }      history := new(AssetHistory)      if err := json.Unmarshal(historyVal.GetValue(), history); err != nil {         return shim.Error(fmt.Sprintf("unmarshal error: %s", err))      }      // 过滤掉不是资产转让的记录      if queryType == "exchange" && history.OriginOwnerID == originOwner {         continue      }      histories = append(histories, history)   }   historiesBytes, err := json.Marshal(histories)   if err != nil {      return shim.Error(fmt.Sprintf("marshal error: %s", err))   }   return shim.Success(historiesBytes)}type AssetExchangeChainCode struct {}func (t *AssetExchangeChainCode) Init(stub shim.ChaincodeStubInterface) peer.Response{   return shim.Success(nil)}func (t *AssetExchangeChainCode) Invoke(stub shim.ChaincodeStubInterface) peer.Response{   functionName, args := stub.GetFunctionAndParameters()   switch functionName {   case "userRegister":      return userRegister(stub,args)   case "userDestroy":      return userDestroy(stub,args)   case "assetEnroll":      return assetEnroll(stub,args)   case "assetExchange":      return assetExchange(stub,args)   case "queryUser":      return queryUser(stub,args)   case "queryAsset":      return queryAsset(stub,args)   case "queryAssetHistory":      return queryAssetHistory(stub,args)   default:      return shim.Error(fmt.Sprintf("unsupported function: %s", functionName))   }   return shim.Success(nil)}func main() {   err := shim.Start(new(AssetExchangeChainCode))   if err != nil {      fmt.Printf("Error starting AssetExchange chaincode: %s", err)   }}

2、链码编译

在Fabric工程AssetExchange/chaincode/assetexchange目录下编译链码：
go build -o assetexchange
编译成功的关键在于确保Fabric依赖的第三方包能够正确被从网络上下载到本地。由于部分第三方依赖包可能从google.golang.org下载，因此需要确保网络可以正确下载。

三、链码部署

1、Fabric区块链网络部署

进入Fabric工程AssetExchange/deploy
docker-compose up
启动服务是否正确启动，确保orderer、peer、cli节点都正确启动。
docker ps
进入cli容器：
docker exec -it cli bash
进入/etc/hyperledger/channel-artifacts目录：
cd /etc/hyperledger/channel-artifacts
创建业务通道：
peer channel create -o orderer.example.com:7050 -c assetchannel -f assetchannel.tx
在当前目录下会生成assetchannel.block区块
加入通道
peer channel join -b assetchannel.block
设置主节点
peer channel update -o orderer.example.com:7050 -c assetchannel -f Org1MSPanchors.tx

2、链码安装

安装assetexchange链码：
peer chaincode install -n assetexchange -v 1.0.0 -l golang -p github.com/chaincode/assetexchange

3、链码实例化

实例化assetexchange链码：
peer chaincode instantiate -o orderer.example.com:7050 -C assetchannel -n assetexchange -l golang -v 1.0.0 -c '{"Args":["user1","0"]}'

4、链码交互

用户注册：
peer chaincode invoke -C assetchannel -n assetexchange -c '{"Args":["userRegister", "user1", "user1"]}'
资产登记：
peer chaincode invoke -C assetchannel -n assetexchange -c '{"Args":["assetEnroll", "asset1", "asset1", "metadata", "user1"]}'
用户注册：
peer chaincode invoke -C assetchannel -n assetexchange -c '{"Args":["userRegister", "user2", "user2"]}'
资产转让：
peer chaincode invoke -C assetchannel -n assetexchange -c '{"Args":["assetExchange", "user1", "asset1", "user2"]}'
用户注销：
peer chaincode invoke -C assetchannel -n assetexchange -c '{"Args":["userDestroy", "user1"]}'

5、链码查询

用户查询：
peer chaincode query -C assetchannel -n assetexchange -c '{"Args":["queryUser", "user1"]}'
资产查询：
peer chaincode query -C assetchannel -n assetexchange -c '{"Args":["queryAsset", "asset1"]}'
用户查询：
peer chaincode query -C assetchannel -n assetexchange -c '{"Args":["queryUser", "user2"]}'
资产交易记录查询：
peer chaincode query -C assetchannel -n assetexchange -c '{"Args":["queryAssetHistory", "asset1"]}'
peer chaincode query -C assetchannel -n assetexchange -c '{"Args":["queryAssetHistory", "asset1", "all"]}'

6、链码升级

peer chaincode install -n assetexchange -v 1.0.1 -l golang -p github.com/chaincode/assetexchange
peer chaincode upgrade -C assetchannel -n assetexchange -v 1.0.1 -c '{"Args":[""]}'