# 智能合约使用01

## 下载示例

```
git clone -b master https://github.com/hyperledger/fabric-samples.git
cd fabric-samples
git checkout v1.1.0
```

## 安装依赖包

```
cd fabric-samples/fabcar
./npm install
```

## 查看合约内容

智能合约文件在：

```
fabric-samples/chaincode/fabcar/go/fabcar.go
```

```
package main

// 后两个引用是智能合约相关的
import (
	"bytes"
	"encoding/json"
	"fmt"
	"strconv"
	"github.com/hyperledger/fabric/core/chaincode/shim"
	sc "github.com/hyperledger/fabric/protos/peer"
)

// 合约结构
type SmartContract struct {
}

// Car结构
type Car struct {
	Make   string `json:"make"`
	Model  string `json:"model"`
	Colour string `json:"colour"`
	Owner  string `json:"owner"`
}

// 合约初始化
func (s *SmartContract) Init(APIstub shim.ChaincodeStubInterface) sc.Response {
	return shim.Success(nil)
}

//消息分发函数
//通过这个函数响应对应的消息，调用后面的功能函数
func (s *SmartContract) Invoke(APIstub shim.ChaincodeStubInterface) sc.Response {

	// Retrieve the requested Smart Contract function and arguments
	function, args := APIstub.GetFunctionAndParameters()
	// Route to the appropriate handler function to interact with the ledger appropriately
	if function == "queryCar" {
		return s.queryCar(APIstub, args)
	} else if function == "initLedger" {
		return s.initLedger(APIstub)
	} else if function == "createCar" {
		return s.createCar(APIstub, args)
	} else if function == "queryAllCars" {
		return s.queryAllCars(APIstub)
	} else if function == "changeCarOwner" {
		return s.changeCarOwner(APIstub, args)
	}

	return shim.Error("Invalid Smart Contract function name.")
}

//根据条件查询车
func (s *SmartContract) queryCar(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {

	if len(args) != 1 {
		return shim.Error("Incorrect number of arguments. Expecting 1")
	}

	carAsBytes, _ := APIstub.GetState(args[0])
	return shim.Success(carAsBytes)
}

//初始化合约数据
func (s *SmartContract) initLedger(APIstub shim.ChaincodeStubInterface) sc.Response {
	cars := []Car{
		Car{Make: "Toyota", Model: "Prius", Colour: "blue", Owner: "Tomoko"},
		Car{Make: "Ford", Model: "Mustang", Colour: "red", Owner: "Brad"},
		Car{Make: "Hyundai", Model: "Tucson", Colour: "green", Owner: "Jin Soo"},
		Car{Make: "Volkswagen", Model: "Passat", Colour: "yellow", Owner: "Max"},
		Car{Make: "Tesla", Model: "S", Colour: "black", Owner: "Adriana"},
		Car{Make: "Peugeot", Model: "205", Colour: "purple", Owner: "Michel"},
		Car{Make: "Chery", Model: "S22L", Colour: "white", Owner: "Aarav"},
		Car{Make: "Fiat", Model: "Punto", Colour: "violet", Owner: "Pari"},
		Car{Make: "Tata", Model: "Nano", Colour: "indigo", Owner: "Valeria"},
		Car{Make: "Holden", Model: "Barina", Colour: "brown", Owner: "Shotaro"},
	}

	i := 0
	for i < len(cars) {
		fmt.Println("i is ", i)
		carAsBytes, _ := json.Marshal(cars[i])
		APIstub.PutState("CAR"+strconv.Itoa(i), carAsBytes)
		fmt.Println("Added", cars[i])
		i = i + 1
	}

	return shim.Success(nil)
}

//新建一辆车
func (s *SmartContract) createCar(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {

	if len(args) != 5 {
		return shim.Error("Incorrect number of arguments. Expecting 5")
	}

	var car = Car{Make: args[1], Model: args[2], Colour: args[3], Owner: args[4]}

	carAsBytes, _ := json.Marshal(car)
	APIstub.PutState(args[0], carAsBytes)

	return shim.Success(nil)
}

//查询全部的车
func (s *SmartContract) queryAllCars(APIstub shim.ChaincodeStubInterface) sc.Response {

	startKey := "CAR0"
	endKey := "CAR999"

	resultsIterator, err := APIstub.GetStateByRange(startKey, endKey)
	if err != nil {
		return shim.Error(err.Error())
	}
	defer resultsIterator.Close()

	// buffer is a JSON array containing QueryResults
	var buffer bytes.Buffer
	buffer.WriteString("[")

	bArrayMemberAlreadyWritten := false
	for resultsIterator.HasNext() {
		queryResponse, err := resultsIterator.Next()
		if err != nil {
			return shim.Error(err.Error())
		}
		// Add a comma before array members, suppress it for the first array member
		if bArrayMemberAlreadyWritten == true {
			buffer.WriteString(",")
		}
		buffer.WriteString("{\"Key\":")
		buffer.WriteString("\"")
		buffer.WriteString(queryResponse.Key)
		buffer.WriteString("\"")

		buffer.WriteString(", \"Record\":")
		// Record is a JSON object, so we write as-is
		buffer.WriteString(string(queryResponse.Value))
		buffer.WriteString("}")
		bArrayMemberAlreadyWritten = true
	}
	buffer.WriteString("]")

	fmt.Printf("- queryAllCars:\n%s\n", buffer.String())

	return shim.Success(buffer.Bytes())
}

//修改车主
func (s *SmartContract) changeCarOwner(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {

	if len(args) != 2 {
		return shim.Error("Incorrect number of arguments. Expecting 2")
	}

	carAsBytes, _ := APIstub.GetState(args[0])
	car := Car{}

	json.Unmarshal(carAsBytes, &car)
	car.Owner = args[1]

	carAsBytes, _ = json.Marshal(car)
	APIstub.PutState(args[0], carAsBytes)

	return shim.Success(nil)
}

//测试代码
func main() {

	// Create a new Smart Contract
	err := shim.Start(new(SmartContract))
	if err != nil {
		fmt.Printf("Error creating new Smart Contract: %s", err)
	}
}

```

## 部署合约

```
./startFabric.sh

#清理工作
sudo docker-compose -f docker-compose.yml down
Removing network net_basic
WARNING: Network net_basic not found.

#开启虚机准备网络
sudo docker-compose -f docker-compose.yml up -d ca.example.com orderer.example.com peer0.org1.example.com couchdb
Creating network "net_basic" with the default driver
Creating orderer.example.com ...
Creating couchdb ...
Creating ca.example.com ...
Creating couchdb
Creating orderer.example.com
Creating couchdb ... done
Creating peer0.org1.example.com ...
Creating peer0.org1.example.com ... done

#等待启动完毕
# wait for Hyperledger Fabric to start

#开启管道
#节点加入管道
# Create the channel
sudo docker exec -e "CORE_PEER_LOCALMSPID=Org1MSP" -e "CORE_PEER_MSPCONFIGPATH=/etc/hyperledger/msp/users/Admin@org1.example.com/msp" peer0.org1.example.com peer channel create -o orderer.example.com:7050 -c mychannel -f /etc/hyperledger/configtx/channel.tx
# Join peer0.org1.example.com to the channel.
sudo docker exec -e "CORE_PEER_LOCALMSPID=Org1MSP" -e "CORE_PEER_MSPCONFIGPATH=/etc/hyperledger/msp/users/Admin@org1.example.com/msp" peer0.org1.example.com peer channel join -b mychannel.block

#开启cli
Creating cli ...
Creating cli ... done

#部署合约

#完成
Total setup execution time : 37 secs ...
```

## 创建用户

```
node enrollAdmin.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully enrolled admin user "admin"
Assigned the admin user to the fabric client ::{"name":"admin","mspid":"Org1MSP","roles":null,"affiliation":"","enrollmentSecret":"","enrollment":{"signingIdentity":"b07a6f50d049f48f9956aca0681e9008011580571539e1ec5f77277749748468","identity":{"certificate":"-----BEGIN CERTIFICATE-----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\nn8oxAiA4sVMzhvkCUvZ6f723pqKe7Ot6HK/Bxn0+Yc28M+uJUw==\n-----END CERTIFICATE-----\n"}}}

node registerUser.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded admin from persistence
Successfully registered user1 - secret:NlaDuZJaUyMp
Successfully enrolled member user "user1"
User1 was successfully registered and enrolled and is ready to intreact with the fabric network
```

## 查询全部数据

```
node query.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded user1 from persistence
Query has completed, checking results
Response is  [{"Key":"CAR0", "Record":{"colour":"blue","make":"Toyota","model":"Prius","owner":"Tomoko"}},{"Key":"CAR1", "Record":{"colour":"red","make":"Ford","model":"Mustang","owner":"Brad"}},{"Key":"CAR2", "Record":{"colour":"green","make":"Hyundai","model":"Tucson","owner":"Jin Soo"}},{"Key":"CAR3", "Record":{"colour":"yellow","make":"Volkswagen","model":"Passat","owner":"Max"}},{"Key":"CAR4", "Record":{"colour":"black","make":"Tesla","model":"S","owner":"Adriana"}},{"Key":"CAR5", "Record":{"colour":"purple","make":"Peugeot","model":"205","owner":"Michel"}},{"Key":"CAR6", "Record":{"colour":"white","make":"Chery","model":"S22L","owner":"Aarav"}},{"Key":"CAR7", "Record":{"colour":"violet","make":"Fiat","model":"Punto","owner":"Pari"}},{"Key":"CAR8", "Record":{"colour":"indigo","make":"Tata","model":"Nano","owner":"Valeria"}},{"Key":"CAR9", "Record":{"colour":"brown","make":"Holden","model":"Barina","owner":"Shotaro"}}]

```

## 带条件的查询

```
#修改query.js的这部分内容
const request = {
		chaincodeId: 'fabcar',
		fcn: 'queryCar',
		args: ['CAR4']
	};
```

```
node query.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded user1 from persistence
Query has completed, checking results
Response is  {"colour":"black","make":"Tesla","model":"S","owner":"Adriana"}
```

## 更新数据

```
#修改invoke.js的这部分内容
var request = {
		chaincodeId: 'fabcar',
		fcn: 'changeCarOwner',
		args: ['CAR10', 'Dave'],
		chainId: 'mychannel',
		txId: tx_id
	};
```

```
#修改所有权
node invoke.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded user1 from persistence
Assigning transaction_id:  a126f84d2ec199abacb59eedfeba29d223534efdf8f01333da66908b97aa94e5
Transaction proposal was good
Successfully sent Proposal and received ProposalResponse: Status - 200, message - "OK"
The transaction has been committed on peer localhost:7053
Send transaction promise and event listener promise have completed
Successfully sent transaction to the orderer.
Successfully committed the change to the ledger by the peer

#查询所有权
node query.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded user1 from persistence
Query has completed, checking results
Response is  {"colour":"red","make":"Ford","model":"Mustang","owner":"neohope"}
```

## 新增数据

```
#修改invoke.js的这部分内容
var request = {
		chaincodeId: 'fabcar',
		fcn: 'createCar',
		args: ['CAR10', 'Honda', 'Accord', 'Black', 'Tom'],
		chainId: 'mychannel',
		txId: tx_id
	};

#修改query.js的这部分内容
const request = {
		chaincodeId: 'fabcar',
		fcn: 'queryCar',
		args: ['CAR10']
	};
```

```
node invoke.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded user1 from persistence
Assigning transaction_id:  cecf39954c4badd43691fe2fa0a124cb19cf66736837366e698134d5b91cfe1b
Transaction proposal was good
Successfully sent Proposal and received ProposalResponse: Status - 200, message - "OK"
The transaction has been committed on peer localhost:7053
Send transaction promise and event listener promise have completed
Successfully sent transaction to the orderer.
Successfully committed the change to the ledger by the peer


node query.js
Store path:/home/neohope/fabric-samples/fabcar/hfc-key-store
Successfully loaded user1 from persistence
Query has completed, checking results
Response is  {"colour":"Black","make":"Honda","model":"Accord","owner":"Tom"}
```

## 停止网络

```
cd fabric-samples/basic-network
./stop.sh
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://neochain.gitbook.io/project/fabric/zhi-neng-he-yue-shi-yong-01.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.