Hyperledger Fabric 2.x Java 區塊鏈應用
一、說明
本文將使用
Java 程式碼基於
fabric-gateway-java 進行區塊鏈網路的訪問與交易，並整合
SpringBoot 框架。
Fabric Gateway SDK 實現 Fabric 的程式設計模型，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託給其閘道器，每個閘道器都瞭解網路通道拓撲，包括組織的多個 Peer 節點和排序節點，使應用程式專注於業務邏輯；Peer 節點可以使用 gossip 協議在組織內部和組織之間相互通訊。
二、Mavn 依賴
新增閘道器 sdk 的依賴：
<dependency> <groupId>org.hyperledger.fabric</groupId> <artifactId>fabric-gateway-java</artifactId> <version>2.2.3</version></dependency>
三、準備配置檔案
工程的目錄結構如下圖所示：
3.1. 準備網路證照
建立目錄
crypto-config 把
orderer 和
peer 節點的證照檔案複製進來。
證照檔案從
fabric-samples 的
test-network 目錄中複製
ordererOrganizations 與
peerOrganizations 資料夾：
3.2. 建立網路配置
建立檔案
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/Admin@org1.example.com/msp/keystore/priv_sk"
}, "signedCertPEM": { "path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp/signcerts/Admin@org1.example.com-cert.pem"
}
}, "Org2": { "mspid": "Org2MSP", "peers": [ "peer0.org2.example.com"
], "certificateAuthorities": [ "ca-org2"
], "adminPrivateKeyPEM": { "path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/users/Admin@org2.example.com/msp/keystore/priv_sk"
}, "signedCertPEM": { "path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/users/Admin@org2.example.com/msp/signcerts/Admin@org2.example.com-cert.pem"
}
}
}, "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/Admin@example.com/msp/keystore/priv_sk"
}, "signedCertPEM": { "path": "src/main/resources/crypto-config/ordererOrganizations/example.com/users/Admin@example.com/msp/signcerts/Admin@example.com-cert.pem"
}
}
}, "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 中新增以下內容，用於訪問閘道器的相關配置：
fabric: # wallet資料夾路徑(自動建立) walletDirectory: wallet # 網路配置檔案路徑 networkConfigPath: connection.json # 使用者證照路徑 certificatePath: crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/signcerts/User1@org1.example.com-cert.pem # 使用者私鑰路徑 privateKeyPath: crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/keystore/priv_sk # 訪問的組織名 mspid: Org1MSP # 使用者名稱 username: user1 # 通道名字 channelName: mychannel # 鏈碼名字 contractName: mycc
四、連線合約
分別構建閘道器、通道和合約的 Bean 物件，程式碼如下：
/**
* 連線閘道器
*/@Beanpublic Gateway connectGateway() throws IOException, InvalidKeyException, CertificateException { //使用org1中的user1初始化一個閘道器wallet賬戶用於連線網路
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網路連線物件
Gateway.Builder builder = Gateway.createBuilder()
.identity(wallet, username)
.networkConfig(Paths.get(this.networkConfigPath)); //連線閘道器
return builder.connect();
}/**
* 獲取通道
*/@Beanpublic Network network(Gateway gateway) { return gateway.getNetwork(this.channelName);
}/**
* 獲取合約
*/@Beanpublic Contract contract(Network network) { return network.getContract(this.contractName);
}
五、合約呼叫
建立 controller 類，注入 Contract 物件呼叫合約方法：
@Resourceprivate Contract contract;@Resourceprivate 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、測試介面
呼叫介面
getUser：
返回：
{ "money": 300, "name": "zlt", "userId": "1"}
呼叫介面
addUser：
返回：
2ae291bb6a366b5ba01ad49e4237da8def9e9828cc2c982e8c49d4b763af0157
來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/70019616/viewspace-2905322/，如需轉載，請註明出處，否則將追究法律責任。