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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 客戶端進行合約的調(diào)用淘菩；本文將使用 Java 代碼基于 fabric-gateway-java 進行區(qū)塊鏈網(wǎng)絡的訪問與交易，并集成 SpringBoot 框架忧换。
Fabric Gateway SDK 實現(xiàn)Fabric的編程模型，提供了一系列簡單的API給應用程序與Fabric區(qū)塊鏈網(wǎng)絡進行交互向拆；
網(wǎng)絡拓撲圖：
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應用程序?qū)⒏髯缘木W(wǎng)絡交互委托給其網(wǎng)關(guān)亚茬，每個網(wǎng)關(guān)都了解網(wǎng)絡信道拓撲，包括組織的多個Peer節(jié)點和排序節(jié)點浓恳，使應用程序?qū)Ｗ⒂跇I(yè)務邏輯刹缝；Peer節(jié)點可以使用gossip協(xié)議在組織內(nèi)部和組織之間相互通信。
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二奖蔓、Mavn依賴
添加網(wǎng)關(guān)sdk的依賴：
<dependency>
<groupId>org.hyperledger.fabric</groupId>
<artifactId>fabric-gateway-java</artifactId>
<version>2.2.3</version>
</dependency>
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三赞草、準備配置文件
工程的目錄結(jié)構(gòu)如下圖所示：
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3.1. 準備網(wǎng)絡證書
創(chuàng)建目錄 crypto-config 把 orderer 和 peer 節(jié)點的證書文件復制進來。
證書文件從 fabric-samples 的 test-network 目錄中復制 ordererOrganizations 與 peerOrganizations 文件夾：
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3.2. 創(chuàng)建網(wǎng)絡配置
創(chuàng)建文件 connection.json 內(nèi)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中的地址吆鹤，內(nèi)容中分別包含了
channels厨疙、organizations、orderers疑务、peers沾凄、ca的配置
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3.3. SpringBoot配置
在 application.yml 中添加以下內(nèi)容，用于訪問網(wǎng)關(guān)的相關(guān)配置：
fabric:
# wallet文件夾路徑(自動創(chuàng)建)
walletDirectory: wallet
# 網(wǎng)絡配置文件路徑
networkConfigPath: connection.json
# 用戶證書路徑
certificatePath: crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/signcerts/User1@org1.example.com-cert.pem
# 用戶私鑰路徑
privateKeyPath: crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/keystore/priv_sk
# 訪問的組織名
mspid: Org1MSP
# 用戶名
username: user1
# 通道名字
channelName: mychannel
# 鏈碼名字
contractName: mycc
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四知允、連接合約
分別構(gòu)建網(wǎng)關(guān)撒蟀、通道和合約的Bean對象，代碼如下：
/**
* 連接網(wǎng)關(guān)
*/
@Bean
public Gateway connectGateway() throws IOException, InvalidKeyException, CertificateException {
//使用org1中的user1初始化一個網(wǎng)關(guān)wallet賬戶用于連接網(wǎng)絡
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(jù)connection.json 獲取Fabric網(wǎng)絡連接對象
Gateway.Builder builder = Gateway.createBuilder()
.identity(wallet, username)
.networkConfig(Paths.get(this.networkConfigPath));
//連接網(wǎng)關(guān)
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);
}
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五温鸽、合約調(diào)用
創(chuàng)建controller類保屯，注入Contract對象調(diào)用合約方法：
@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;
}
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六、測試接口
調(diào)用接口 getUser：
http://127.0.0.1:9001/getUser?userId=1
返回：
{
"money": 300,
"name": "zlt",
"userId": "1"
}
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調(diào)用接口 addUser：
http://127.0.0.1:9001/addUser?userId=6&userName=test6&money=600
返回：
2ae291bb6a366b5ba01ad49e4237da8def9e9828cc2c982e8c49d4b763af0157
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七涤垫、代碼下載
gitee：https://gitee.com/zlt2000/my-fabric-application-java
github：https://github.com/zlt2000/my-fabric-application-java
