https://blog.csdn.net/lakersssss24/article/details/125762826?spm=1001.2014.3001.5501
https://blog.csdn.net/lakersssss24/article/details/126434147
https://blog.csdn.net/lakersssss24/article/details/126671408?spm=1001.2101.3001.6650.3&utm_medium=distribute.pc_relevant.none-task-blog-2%7Edefault%7EBlogCommendFromBaidu%7ERate-3-126671408-blog-126434147.pc_relevant_3mothn_strategy_and_data_recovery&depth_1-utm_source=distribute.pc_relevant.none-task-blog-2%7Edefault%7EBlogCommendFromBaidu%7ERate-3-126671408-blog-126434147.pc_relevant_3mothn_strategy_and_data_recovery&utm_relevant_index=4
Prepare in advance
sudo apt-get update 更新源
sudo apt-get install ssh 安装远程客户端
sudo apt-get install curl 安装命令行工具
sudo apt-get install git 安装git
sudo apt-get install gcc 安装gcc
sudo apt-get install vim 安装vim文件编辑器
sudo apt-get install make 安装make
sudo apt-get install net-tools 安装网络工具
sudo apt-get install net-tools 安装mousepad 类似于windows的记事本
./bootstrap.sh
https://teach.imcn.me/y2020/1146.html
couchDB installation https://blog.csdn.net/TU_Dresden/article/details/126864418
experiment one
network
./network.sh up
./network.sh up createChannel -s couchdb
./network.sh deployCC -ccn basic -ccp ../asset-transfer-basic/chaincode-go -ccl go
export PATH=${
PWD}/../bin:$PATH
export FABRIC_CFG_PATH=$PWD/../config/
export CORE_PEER_TLS_ENABLED=true
export CORE_PEER_LOCALMSPID="Org1MSP"
export CORE_PEER_TLS_ROOTCERT_FILE=${
PWD}/organizations/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt
export CORE_PEER_MSPCONFIGPATH=${
PWD}/organizations/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp
export CORE_PEER_ADDRESS=localhost:7051
peer chaincode invoke -o localhost:7050 --ordererTLSHostnameOverride orderer.example.com --tls --cafile "${PWD}/organizations/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem" -C mychannel -n basic --peerAddresses localhost:7051 --tlsRootCertFiles "${PWD}/organizations/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt" --peerAddresses localhost:9051 --tlsRootCertFiles "${PWD}/organizations/peerOrganizations/org2.example.com/peers/peer0.org2.example.com/tls/ca.crt" -c '{
"function":"InitLedger","Args":[""]}'
restart
./network.sh up createChannel -ca -s couchdb
gin template
package main
import (
"fmt"
"github.com/gin-gonic/gin"
)
type Stu struct {
Name string `form:"name"`
Id string `form:"id"`
Age string `form:"age"`
}
func main() {
r := gin.Default()
var stu Stu
r1 := r.Group("/fabric2.4")
r1.POST("/setstu", func(c *gin.Context) {
//var stu Stu
c.ShouldBind(&stu)
c.JSON(200, stu)
fmt.Println("stu:", stu)
})
r1.POST("/ok1", func(c *gin.Context) {
c.JSON(200, "ok1")
})
r.Run(":8080") // 监听并在 0.0.0.0:8080 上启动服务
}
The only functional part of the chaincode:
package chaincode
import (
"encoding/json"
"fmt"
"github.com/hyperledger/fabric-contract-api-go/contractapi"
)
// SmartContract provides functions for managing an Asset
type SmartContract struct {
contractapi.Contract
}
// Asset describes basic details of what makes up a simple asset
//Insert struct field in alphabetic order => to achieve determinism across languages
// golang keeps the order when marshal to json but doesn't order automatically
type Asset struct {
AppraisedValue int `json:"AppraisedValue"`
Color string `json:"Color"`
ID string `json:"ID"`
Owner string `json:"Owner"`
Size int `json:"Size"`
}
// InitLedger adds a base set of assets to the ledger
func (s *SmartContract) InitLedger(ctx contractapi.TransactionContextInterface) error {
assets := []Asset{
{
ID: "asset1", Color: "blue", Size: 5, Owner: "Tomoko", AppraisedValue: 300},
{
ID: "asset2", Color: "red", Size: 5, Owner: "Brad", AppraisedValue: 400},
{
ID: "asset3", Color: "green", Size: 10, Owner: "Jin Soo", AppraisedValue: 500},
{
ID: "asset4", Color: "yellow", Size: 10, Owner: "Max", AppraisedValue: 600},
{
ID: "asset5", Color: "black", Size: 15, Owner: "Adriana", AppraisedValue: 700},
{
ID: "asset6", Color: "white", Size: 15, Owner: "Michel", AppraisedValue: 800},
}
for _, asset := range assets {
assetJSON, err := json.Marshal(asset)
if err != nil {
return err
}
err = ctx.GetStub().PutState(asset.ID, assetJSON)
if err != nil {
return fmt.Errorf("failed to put to world state. %v", err)
}
}
return nil
}
// CreateAsset issues a new asset to the world state with given details.
func (s *SmartContract) CreateAsset(ctx contractapi.TransactionContextInterface, id string, color string, size int, owner string, appraisedValue int) error {
exists, err := s.AssetExists(ctx, id)
if err != nil {
return err
}
if exists {
return fmt.Errorf("the asset %s already exists", id)
}
asset := Asset{
ID: id,
Color: color,
Size: size,
Owner: owner,
AppraisedValue: appraisedValue,
}
assetJSON, err := json.Marshal(asset)
if err != nil {
return err
}
return ctx.GetStub().PutState(id, assetJSON)
}
// ReadAsset returns the asset stored in the world state with given id.
func (s *SmartContract) ReadAsset(ctx contractapi.TransactionContextInterface, id string) (*Asset, error) {
assetJSON, err := ctx.GetStub().GetState(id)
if err != nil {
return nil, fmt.Errorf("failed to read from world state: %v", err)
}
if assetJSON == nil {
return nil, fmt.Errorf("the asset %s does not exist", id)
}
var asset Asset
err = json.Unmarshal(assetJSON, &asset)
if err != nil {
return nil, err
}
return &asset, nil
}
// UpdateAsset updates an existing asset in the world state with provided parameters.
func (s *SmartContract) UpdateAsset(ctx contractapi.TransactionContextInterface, id string, color string, size int, owner string, appraisedValue int) error {
exists, err := s.AssetExists(ctx, id)
if err != nil {
return err
}
if !exists {
return fmt.Errorf("the asset %s does not exist", id)
}
// overwriting original asset with new asset
asset := Asset{
ID: id,
Color: color,
Size: size,
Owner: owner,
AppraisedValue: appraisedValue,
}
assetJSON, err := json.Marshal(asset)
if err != nil {
return err
}
return ctx.GetStub().PutState(id, assetJSON)
}
// DeleteAsset deletes an given asset from the world state.
func (s *SmartContract) DeleteAsset(ctx contractapi.TransactionContextInterface, id string) error {
exists, err := s.AssetExists(ctx, id)
if err != nil {
return err
}
if !exists {
return fmt.Errorf("the asset %s does not exist", id)
}
return ctx.GetStub().DelState(id)
}
// AssetExists returns true when asset with given ID exists in world state
func (s *SmartContract) AssetExists(ctx contractapi.TransactionContextInterface, id string) (bool, error) {
assetJSON, err := ctx.GetStub().GetState(id)
if err != nil {
return false, fmt.Errorf("failed to read from world state: %v", err)
}
return assetJSON != nil, nil
}
// TransferAsset updates the owner field of asset with given id in world state, and returns the old owner.
func (s *SmartContract) TransferAsset(ctx contractapi.TransactionContextInterface, id string, newOwner string) (string, error) {
asset, err := s.ReadAsset(ctx, id)
if err != nil {
return "", err
}
oldOwner := asset.Owner
asset.Owner = newOwner
assetJSON, err := json.Marshal(asset)
if err != nil {
return "", err
}
err = ctx.GetStub().PutState(id, assetJSON)
if err != nil {
return "", err
}
return oldOwner, nil
}
// GetAllAssets returns all assets found in world state
func (s *SmartContract) GetAllAssets(ctx contractapi.TransactionContextInterface) ([]*Asset, error) {
// range query with empty string for startKey and endKey does an
// open-ended query of all assets in the chaincode namespace.
resultsIterator, err := ctx.GetStub().GetStateByRange("", "")
if err != nil {
return nil, err
}
defer resultsIterator.Close()
var assets []*Asset
for resultsIterator.HasNext() {
queryResponse, err := resultsIterator.Next()
if err != nil {
return nil, err
}
var asset Asset
err = json.Unmarshal(queryResponse.Value, &asset)
if err != nil {
return nil, err
}
assets = append(assets, &asset)
}
return assets, nil
}
View the IP and address of the virtual machine:
ifconfig
gin framework
package main
import (
"bytes"
"crypto/x509"
"encoding/json"
"fmt"
"github.com/gin-gonic/gin"
"github.com/hyperledger/fabric-gateway/pkg/client"
"github.com/hyperledger/fabric-gateway/pkg/identity"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"io/ioutil"
"path"
"time"
)
const (
mspID = "Org1MSP"
cryptoPath = "./peerOrganizations/org1.example.com"
certPath = cryptoPath + "/users/[email protected]/msp/signcerts/cert.pem"
keyPath = cryptoPath + "/users/[email protected]/msp/keystore/"
tlsCertPath = cryptoPath + "/peers/peer0.org1.example.com/tls/ca.crt"
peerEndpoint = "192.168.136.130:7051"
gatewayPeer = "peer0.org1.example.com"
channelName = "mychannel"
chaincodeName = "basic"
)
type Asset struct {
AppraisedValue int `form:"appraisedValue" json:"appraisedValue" `
Color string `form:"color" json:"color"`
ID string `form:"id" json:"id"`
Owner string `form:"owner" json:"owner"`
Size int `form:"size" json:"size"`
}
func main() {
// The gRPC client connection should be shared by all Gateway connections to this endpoint
clientConnection := newGrpcConnection()
defer clientConnection.Close()
id := newIdentity()
sign := newSign()
// Create a Gateway connection for a specific client identity
gateway, err := client.Connect(
id,
client.WithSign(sign),
client.WithClientConnection(clientConnection),
// Default timeouts for different gRPC calls
client.WithEvaluateTimeout(5*time.Second),
client.WithEndorseTimeout(15*time.Second),
client.WithSubmitTimeout(5*time.Second),
client.WithCommitStatusTimeout(1*time.Minute),
)
if err != nil {
panic(err)
}
defer gateway.Close()
network := gateway.GetNetwork(channelName)
contract := network.GetContract(chaincodeName)
r := gin.Default()
r1 := r.Group("/fabric2.4")
r1.POST("/CreateAsset", func(c *gin.Context) {
var asset Asset
c.ShouldBind(&asset)
c.JSON(200, asset)
marshal, _ := json.Marshal(asset)
fmt.Println(string(marshal))
fmt.Println("asset:", asset)
})
r1.POST("/GetAllAssets", func(c *gin.Context) {
result := getAllAssets(contract)
c.JSON(200, result)
})
r.Run(":8080") // 监听并在 0.0.0.0:8080 上启动服务
}
// Evaluate a transaction to query ledger state.
func getAllAssets(contract *client.Contract) string {
fmt.Println("Evaluate Transaction: GetAllAssets, function returns all the current assets on the ledger")
evaluateResult, err := contract.EvaluateTransaction("GetAllAssets")
if err != nil {
panic(fmt.Errorf("failed to evaluate transaction: %w", err))
}
result := formatJSON(evaluateResult)
fmt.Printf("*** Result:%s\n", result)
return string(evaluateResult)
}
// newGrpcConnection creates a gRPC connection to the Gateway server.
func newGrpcConnection() *grpc.ClientConn {
certificate, err := loadCertificate(tlsCertPath)
if err != nil {
panic(err)
}
certPool := x509.NewCertPool()
certPool.AddCert(certificate)
transportCredentials := credentials.NewClientTLSFromCert(certPool, gatewayPeer)
connection, err := grpc.Dial(peerEndpoint, grpc.WithTransportCredentials(transportCredentials))
if err != nil {
panic(fmt.Errorf("failed to create gRPC connection: %w", err))
}
return connection
}
// newIdentity creates a client identity for this Gateway connection using an X.509 certificate.
func newIdentity() *identity.X509Identity {
certificate, err := loadCertificate(certPath)
if err != nil {
panic(err)
}
id, err := identity.NewX509Identity(mspID, certificate)
if err != nil {
panic(err)
}
return id
}
func loadCertificate(filename string) (*x509.Certificate, error) {
certificatePEM, err := ioutil.ReadFile(filename)
if err != nil {
return nil, fmt.Errorf("failed to read certificate file: %w", err)
}
return identity.CertificateFromPEM(certificatePEM)
}
// newSign creates a function that generates a digital signature from a message digest using a private key.
func newSign() identity.Sign {
files, err := ioutil.ReadDir(keyPath)
if err != nil {
panic(fmt.Errorf("failed to read private key directory: %w", err))
}
privateKeyPEM, err := ioutil.ReadFile(path.Join(keyPath, files[0].Name()))
if err != nil {
panic(fmt.Errorf("failed to read private key file: %w", err))
}
privateKey, err := identity.PrivateKeyFromPEM(privateKeyPEM)
if err != nil {
panic(err)
}
sign, err := identity.NewPrivateKeySign(privateKey)
if err != nil {
panic(err)
}
return sign
}
// Format JSON data
func formatJSON(data []byte) string {
var prettyJSON bytes.Buffer
if err := json.Indent(&prettyJSON, data, " ", ""); err != nil {
panic(fmt.Errorf("failed to parse JSON: %w", err))
}
return prettyJSON.String()
}
chain code
package chaincode
import (
"encoding/json"
"fmt"
"github.com/hyperledger/fabric-contract-api-go/contractapi"
)
// SmartContract provides functions for managing an Asset
type SmartContract struct {
contractapi.Contract
}
// Asset describes basic details of what makes up a simple asset
//Insert struct field in alphabetic order => to achieve determinism across languages
// golang keeps the order when marshal to json but doesn't order automatically
type Asset struct {
AppraisedValue int `json:"AppraisedValue"`
Color string `json:"Color"`
ID string `json:"ID"`
Owner string `json:"Owner"`
Size int `json:"Size"`
}
// InitLedger adds a base set of assets to the ledger
func (s *SmartContract) InitLedger(ctx contractapi.TransactionContextInterface) error {
assets := []Asset{
{
ID: "asset1", Color: "blue", Size: 5, Owner: "Tomoko", AppraisedValue: 300},
{
ID: "asset2", Color: "red", Size: 5, Owner: "Brad", AppraisedValue: 400},
{
ID: "asset3", Color: "green", Size: 10, Owner: "Jin Soo", AppraisedValue: 500},
{
ID: "asset4", Color: "yellow", Size: 10, Owner: "Max", AppraisedValue: 600},
{
ID: "asset5", Color: "black", Size: 15, Owner: "Adriana", AppraisedValue: 700},
{
ID: "asset6", Color: "white", Size: 15, Owner: "Michel", AppraisedValue: 800},
}
for _, asset := range assets {
assetJSON, err := json.Marshal(asset)
if err != nil {
return err
}
err = ctx.GetStub().PutState(asset.ID, assetJSON)
if err != nil {
return fmt.Errorf("failed to put to world state. %v", err)
}
}
return nil
}
// CreateAsset issues a new asset to the world state with given details.
func (s *SmartContract) CreateAsset(ctx contractapi.TransactionContextInterface, id string, color string, size int, owner string, appraisedValue int) error {
exists, err := s.AssetExists(ctx, id)
if err != nil {
return err
}
if exists {
return fmt.Errorf("the asset %s already exists", id)
}
asset := Asset{
ID: id,
Color: color,
Size: size,
Owner: owner,
AppraisedValue: appraisedValue,
}
assetJSON, err := json.Marshal(asset)
if err != nil {
return err
}
return ctx.GetStub().PutState(id, assetJSON)
}
// ReadAsset returns the asset stored in the world state with given id.
func (s *SmartContract) ReadAsset(ctx contractapi.TransactionContextInterface, id string) (*Asset, error) {
assetJSON, err := ctx.GetStub().GetState(id)
if err != nil {
return nil, fmt.Errorf("failed to read from world state: %v", err)
}
if assetJSON == nil {
return nil, fmt.Errorf("the asset %s does not exist", id)
}
var asset Asset
err = json.Unmarshal(assetJSON, &asset)
if err != nil {
return nil, err
}
return &asset, nil
}
// UpdateAsset updates an existing asset in the world state with provided parameters.
func (s *SmartContract) UpdateAsset(ctx contractapi.TransactionContextInterface, id string, color string, size int, owner string, appraisedValue int) error {
exists, err := s.AssetExists(ctx, id)
if err != nil {
return err
}
if !exists {
return fmt.Errorf("the asset %s does not exist", id)
}
// overwriting original asset with new asset
asset := Asset{
ID: id,
Color: color,
Size: size,
Owner: owner,
AppraisedValue: appraisedValue,
}
assetJSON, err := json.Marshal(asset)
if err != nil {
return err
}
return ctx.GetStub().PutState(id, assetJSON)
}
// DeleteAsset deletes an given asset from the world state.
func (s *SmartContract) DeleteAsset(ctx contractapi.TransactionContextInterface, id string) error {
exists, err := s.AssetExists(ctx, id)
if err != nil {
return err
}
if !exists {
return fmt.Errorf("the asset %s does not exist", id)
}
return ctx.GetStub().DelState(id)
}
// AssetExists returns true when asset with given ID exists in world state
func (s *SmartContract) AssetExists(ctx contractapi.TransactionContextInterface, id string) (bool, error) {
assetJSON, err := ctx.GetStub().GetState(id)
if err != nil {
return false, fmt.Errorf("failed to read from world state: %v", err)
}
return assetJSON != nil, nil
}
// TransferAsset updates the owner field of asset with given id in world state, and returns the old owner.
func (s *SmartContract) TransferAsset(ctx contractapi.TransactionContextInterface, id string, newOwner string) (string, error) {
asset, err := s.ReadAsset(ctx, id)
if err != nil {
return "", err
}
oldOwner := asset.Owner
asset.Owner = newOwner
assetJSON, err := json.Marshal(asset)
if err != nil {
return "", err
}
err = ctx.GetStub().PutState(id, assetJSON)
if err != nil {
return "", err
}
return oldOwner, nil
}
// GetAllAssets returns all assets found in world state
func (s *SmartContract) GetAllAssets(ctx contractapi.TransactionContextInterface) ([]*Asset, error) {
// range query with empty string for startKey and endKey does an
// open-ended query of all assets in the chaincode namespace.
resultsIterator, err := ctx.GetStub().GetStateByRange("", "")
if err != nil {
return nil, err
}
defer resultsIterator.Close()
var assets []*Asset
for resultsIterator.HasNext() {
queryResponse, err := resultsIterator.Next()
if err != nil {
return nil, err
}
var asset Asset
err = json.Unmarshal(queryResponse.Value, &asset)
if err != nil {
return nil, err
}
assets = append(assets, &asset)
}
return assets, nil
}
postman
Test your own website:
Local query:
own github:
Experiment 2
gin
package main
import (
"bytes"
"crypto/x509"
"encoding/json"
"fmt"
"github.com/gin-gonic/gin"
"github.com/hyperledger/fabric-gateway/pkg/client"
"github.com/hyperledger/fabric-gateway/pkg/identity"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"io/ioutil"
"path"
"time"
)
const (
mspID = "Org1MSP"
cryptoPath = "./peerOrganizations/org1.example.com"
certPath = cryptoPath + "/users/[email protected]/msp/signcerts/cert.pem"
keyPath = cryptoPath + "/users/[email protected]/msp/keystore/"
tlsCertPath = cryptoPath + "/peers/peer0.org1.example.com/tls/ca.crt"
peerEndpoint = "192.168.136.130:7051"
gatewayPeer = "peer0.org1.example.com"
channelName = "mychannel"
chaincodeName = "basic"
)
type Asset struct {
AppraisedValue int `form:"appraisedValue" json:"appraisedValue" `
Color string `form:"color" json:"color"`
ID string `form:"id" json:"id"`
Owner string `form:"owner" json:"owner"`
Size int `form:"size" json:"size"`
}
func main() {
// The gRPC client connection should be shared by all Gateway connections to this endpoint
clientConnection := newGrpcConnection()
defer clientConnection.Close()
id := newIdentity()
sign := newSign()
// Create a Gateway connection for a specific client identity
gateway, err := client.Connect(
id,
client.WithSign(sign),
client.WithClientConnection(clientConnection),
// Default timeouts for different gRPC calls
client.WithEvaluateTimeout(5*time.Second),
client.WithEndorseTimeout(15*time.Second),
client.WithSubmitTimeout(5*time.Second),
client.WithCommitStatusTimeout(1*time.Minute),
)
if err != nil {
panic(err)
}
defer gateway.Close()
network := gateway.GetNetwork(channelName)
contract := network.GetContract(chaincodeName)
r := gin.Default()
r1 := r.Group("/fabric2.4.2")
r1.POST("/Init", func(c *gin.Context) {
initLedger(contract)
c.JSON(200, "init ok!")
})
r.Run(":8080") // 监听并在 0.0.0.0:8080 上启动服务
}
// Evaluate a transaction to query ledger state.
func getAllAssets(contract *client.Contract) string {
fmt.Println("Evaluate Transaction: GetAllAssets, function returns all the current assets on the ledger")
evaluateResult, err := contract.EvaluateTransaction("GetAllAssets")
if err != nil {
panic(fmt.Errorf("failed to evaluate transaction: %w", err))
}
result := formatJSON(evaluateResult)
fmt.Printf("*** Result:%s\n", result)
return string(evaluateResult)
}
// newGrpcConnection creates a gRPC connection to the Gateway server.
func newGrpcConnection() *grpc.ClientConn {
certificate, err := loadCertificate(tlsCertPath)
if err != nil {
panic(err)
}
certPool := x509.NewCertPool()
certPool.AddCert(certificate)
transportCredentials := credentials.NewClientTLSFromCert(certPool, gatewayPeer)
connection, err := grpc.Dial(peerEndpoint, grpc.WithTransportCredentials(transportCredentials))
if err != nil {
panic(fmt.Errorf("failed to create gRPC connection: %w", err))
}
return connection
}
// newIdentity creates a client identity for this Gateway connection using an X.509 certificate.
func newIdentity() *identity.X509Identity {
certificate, err := loadCertificate(certPath)
if err != nil {
panic(err)
}
id, err := identity.NewX509Identity(mspID, certificate)
if err != nil {
panic(err)
}
return id
}
func loadCertificate(filename string) (*x509.Certificate, error) {
certificatePEM, err := ioutil.ReadFile(filename)
if err != nil {
return nil, fmt.Errorf("failed to read certificate file: %w", err)
}
return identity.CertificateFromPEM(certificatePEM)
}
// newSign creates a function that generates a digital signature from a message digest using a private key.
func newSign() identity.Sign {
files, err := ioutil.ReadDir(keyPath)
if err != nil {
panic(fmt.Errorf("failed to read private key directory: %w", err))
}
privateKeyPEM, err := ioutil.ReadFile(path.Join(keyPath, files[0].Name()))
if err != nil {
panic(fmt.Errorf("failed to read private key file: %w", err))
}
privateKey, err := identity.PrivateKeyFromPEM(privateKeyPEM)
if err != nil {
panic(err)
}
sign, err := identity.NewPrivateKeySign(privateKey)
if err != nil {
panic(err)
}
return sign
}
// Format JSON data
func formatJSON(data []byte) string {
var prettyJSON bytes.Buffer
if err := json.Indent(&prettyJSON, data, " ", ""); err != nil {
panic(fmt.Errorf("failed to parse JSON: %w", err))
}
return prettyJSON.String()
}
New asset part:
change the code below:
to this:
r1.POST("/CreateAsset", func(c *gin.Context) {
var asset Asset
c.ShouldBind(&asset)
c.JSON(200, asset)
marshal, _ := json.Marshal(asset)
CreateAsset(contract, asset)
fmt.Println("存入成功！存入的数据是:", string(marshal))
//fmt.Println("asset:", asset)
})
function:
func CreateAsset(contract *client.Contract, asset Asset) string {
evaluateResult, err := contract.SubmitTransaction("CreateAsset", asset.ID, asset.Color, strconv.Itoa(asset.Size), asset.Owner, strconv.Itoa(asset.AppraisedValue))
if err != nil {
panic(fmt.Errorf("failed to evaluate transaction: %w", err))
}
result := formatJSON(evaluateResult)
fmt.Printf("*** Result:%s\n", result)
return string(evaluateResult)
}
Summarize
The content of this experiment is not much, and it is quite difficult.
One is that the author has set up the framework by default, so it needs to be adapted according to the previous article.
The second is the query after the network is set up. If you read the previous article, you can know that the author has modified the
https://github.com/hyperledger/fabric-samples/tree/main/asset-transfer-basic
Part of the code, which is the gin framework part of this article. There are also a lot of modifications,
and then there is the code. The code often reports an error here, and then in order to solve a bug, it often causes more problems, especially the occupation of the network interface. Just now when writing the document, my 7051 port is inexplicably occupied Yes, in order to better complete the final task, I decided to find a correct and clear document and configure it from scratch. (The big reason is that the entire fabric folder is bloated after these few operations, and there are several fabric-samples. I went back to look at it after a few weeks. , reset to zero is more effective)
Before doing two experiments, I first configured the environment according to the author's ideas, mainly to start the network.
The second is a very new tool, postman, and the purpose of this software has not been fully understood yet. Currently, it is only used for querying URLs.
The second part of the query did not find out the assets. It may be that there is a bug in some aspect. After that, the virtual machine will be re-enabled, and then it will be done from scratch.
