一、說明
在上一篇文章中 《Hyperledger Fabric 2.x 自定義智能合約》 分享了智能合約的安裝并使用 cli 客戶端進行合約的呼叫；本文將使用 Java 代碼基于 fabric-gateway-java 進行區塊鏈網路的訪問與交易，并集成 SpringBoot 框架，
Fabric Gateway SDK 實作Fabric的編程模型，提供了一系列簡單的API給應用程式與Fabric區塊鏈網路進行互動；
網路拓撲圖：
應用程式將各自的網路互動委托給其網關，每個網關都了解網路信道拓撲，包括組織的多個Peer節點和排序節點，使應用程式專注于業務邏輯；Peer節點可以使用gossip協議在組織內部和組織之間相互通信，
二、Mavn依賴
添加網關sdk的依賴：
<dependency>
<groupId>org.hyperledger.fabric</groupId>
<artifactId>fabric-gateway-java</artifactId>
<version>2.2.3</version>
</dependency>
三、準備組態檔
工程的目錄結構如下圖所示：
3.1. 準備網路證書
創建目錄 crypto-config 把 orderer 和 peer 節點的證書檔案復制進來，
證書檔案從 fabric-samples 的 test-network 目錄中復制 ordererOrganizations 與 peerOrganizations 檔案夾：
3.2. 創建網路配置
創建檔案 connection.json 內容如下：
{
"name": "basic-network",
"version": "1.0.0",
"client": {
"organization": "Org1",
"connection": {
"timeout": {
"peer": {
"endorser": "300"
},
"orderer": "300"
}
}
},
"channels": {
"mychannel": {
"orderers": [
"orderer.example.com"
],
"peers": {
"peer0.org1.example.com": {
"endorsingPeer": true,
"chaincodeQuery": true,
"ledgerQuery": true,
"eventSource": true
},
"peer0.org2.example.com": {
"endorsingPeer": true,
"chaincodeQuery": true,
"ledgerQuery": true,
"eventSource": true
}
}
}
},
"organizations": {
"Org1": {
"mspid": "Org1MSP",
"peers": [
"peer0.org1.example.com"
],
"certificateAuthorities": [
"ca-org1"
],
"adminPrivateKeyPEM": {
"path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/keystore/priv_sk"
},
"signedCertPEM": {
"path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/signcerts/[email protected]"
}
},
"Org2": {
"mspid": "Org2MSP",
"peers": [
"peer0.org2.example.com"
],
"certificateAuthorities": [
"ca-org2"
],
"adminPrivateKeyPEM": {
"path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/users/[email protected]/msp/keystore/priv_sk"
},
"signedCertPEM": {
"path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/users/[email protected]/msp/signcerts/[email protected]"
}
}
},
"orderers": {
"orderer.example.com": {
"url": "grpcs://192.168.28.134:7050",
"mspid": "OrdererMSP",
"grpcOptions": {
"ssl-target-name-override": "orderer.example.com",
"hostnameOverride": "orderer.example.com"
},
"tlsCACerts": {
"path": "src/main/resources/crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/ca.crt"
},
"adminPrivateKeyPEM": {
"path": "src/main/resources/crypto-config/ordererOrganizations/example.com/users/[email protected]/msp/keystore/priv_sk"
},
"signedCertPEM": {
"path": "src/main/resources/crypto-config/ordererOrganizations/example.com/users/[email protected]/msp/signcerts/[email protected]"
}
}
},
"peers": {
"peer0.org1.example.com": {
"url": "grpcs://192.168.28.134:7051",
"grpcOptions": {
"ssl-target-name-override": "peer0.org1.example.com",
"hostnameOverride": "peer0.org1.example.com",
"request-timeout": 120001
},
"tlsCACerts": {
"path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt"
}
},
"peer0.org2.example.com": {
"url": "grpcs://192.168.28.134:9051",
"grpcOptions": {
"ssl-target-name-override": "peer0.org2.example.com",
"hostnameOverride": "peer0.org2.example.com",
"request-timeout": 120001
},
"tlsCACerts": {
"path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/peers/peer0.org2.example.com/tls/ca.crt"
}
}
},
"certificateAuthorities": {
"ca-org1": {
"url": "https://192.168.28.134:7054",
"grpcOptions": {
"verify": true
},
"tlsCACerts": {
"path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/ca/ca.org1.example.com-cert.pem"
},
"registrar": [
{
"enrollId": "admin",
"enrollSecret": "adminpw"
}
]
},
"ca-org2": {
"url": "https://192.168.28.134:8054",
"grpcOptions": {
"verify": true
},
"tlsCACerts": {
"path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/ca/ca.org2.example.com-cert.pem"
},
"registrar": [
{
"enrollId": "admin",
"enrollSecret": "adminpw"
}
]
}
}
}
需按實際情況修改url中的地址，內容中分別包含了
channels、organizations、orderers、peers、ca的配置
3.3. SpringBoot配置
在 application.yml 中添加以下內容，用于訪問網關的相關配置：
fabric:
# wallet檔案夾路徑(自動創建)
walletDirectory: wallet
# 網路組態檔路徑
networkConfigPath: connection.json
# 用戶證書路徑
certificatePath: crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/signcerts/[email protected]
# 用戶私鑰路徑
privateKeyPath: crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/keystore/priv_sk
# 訪問的組織名
mspid: Org1MSP
# 用戶名
username: user1
# 通道名字
channelName: mychannel
# 鏈碼名字
contractName: mycc
四、連接合約
分別構建網關、通道和合約的Bean物件，代碼如下：
/**
* 連接網關
*/
@Bean
public Gateway connectGateway() throws IOException, InvalidKeyException, CertificateException {
//使用org1中的user1初始化一個網關wallet賬戶用于連接網路
Wallet wallet = Wallets.newFileSystemWallet(Paths.get(this.walletDirectory));
X509Certificate certificate = readX509Certificate(Paths.get(this.certificatePath));
PrivateKey privateKey = getPrivateKey(Paths.get(this.privateKeyPath));
wallet.put(username, Identities.newX509Identity(this.mspid, certificate, privateKey));
//根據connection.json 獲取Fabric網路連接物件
Gateway.Builder builder = Gateway.createBuilder()
.identity(wallet, username)
.networkConfig(Paths.get(this.networkConfigPath));
//連接網關
return builder.connect();
}
/**
* 獲取通道
*/
@Bean
public Network network(Gateway gateway) {
return gateway.getNetwork(this.channelName);
}
/**
* 獲取合約
*/
@Bean
public Contract contract(Network network) {
return network.getContract(this.contractName);
}
五、合約呼叫
創建controller類，注入Contract物件呼叫合約方法：
@Resource
private Contract contract;
@Resource
private Network network;
@GetMapping("/getUser")
public String getUser(String userId) throws ContractException {
byte[] queryAResultBefore = contract.evaluateTransaction("getUser",userId);
return new String(queryAResultBefore, StandardCharsets.UTF_8);
}
@GetMapping("/addUser")
public String addUser(String userId, String userName, String money) throws ContractException, InterruptedException, TimeoutException {
byte[] invokeResult = contract.createTransaction("addUser")
.setEndorsingPeers(network.getChannel().getPeers(EnumSet.of(Peer.PeerRole.ENDORSING_PEER)))
.submit(userId, userName, money);
String txId = new String(invokeResult, StandardCharsets.UTF_8);
return txId;
}
六、測驗介面
呼叫介面 getUser：
http://127.0.0.1:9001/getUser?userId=1
回傳：
{
"money": 300,
"name": "zlt",
"userId": "1"
}
呼叫介面 addUser：
http://127.0.0.1:9001/addUser?userId=6&userName=test6&money=600
回傳：
2ae291bb6a366b5ba01ad49e4237da8def9e9828cc2c982e8c49d4b763af0157
七、代碼下載
gitee：https://gitee.com/zlt2000/my-fabric-application-java
github：https://github.com/zlt2000/my-fabric-application-java
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標籤：Java