Hyperledger Fabric 2.x Java区块链应用

一、说明

在上一篇文章中《Hyperledger Fabric 2.x 自定义智能合约》分享了智能合约的安装并使用 cli 客户端进行合约的调用；本文将使用 Java 代码基于 fabric-gateway-java 进行区块链网络的访问与交易，并集成 SpringBoot 框架。

Fabric Gateway SDK 实现Fabric的编程模型，提供了一系列简单的API给应用程序与Fabric区块链网络进行交互；

网络拓扑图：

应用程序将各自的网络交互委托给其网关，每个网关都了解网络信道拓扑，包括组织的多个Peer节点和排序节点，使应用程序专注于业务逻辑；Peer节点可以使用gossip协议在组织内部和组织之间相互通信。

二、Mavn依赖

添加网关sdk的依赖：

<dependency><groupId>org.hyperledger.fabric</groupId><artifactId>fabric-gateway-java</artifactId><version>2.2.3</version>
</dependency>

三、准备配置文件

工程的目录结构如下图所示：

3.1. 准备网络证书

创建目录 crypto-config 把 orderer 和 peer 节点的证书文件复制进来。

证书文件从 fabric-samples 的 test-network 目录中复制 ordererOrganizations 与 peerOrganizations 文件夹：

3.2. 创建网络配置

创建文件 connection.json 内容如下：

{"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"}]}}
}

需按实际情况修改url中的地址，内容中分别包含了 channels、organizations、orderers、peers、ca 的配置

3.3. SpringBoot配置

在 application.yml 中添加以下内容，用于访问网关的相关配置：

fabric:# wallet文件夹路径(自动创建)walletDirectory: wallet# 网络配置文件路径networkConfigPath: connection.json# 用户证书路径certificatePath: crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/signcerts/User1@org1.example.com-cert.pem# 用户私钥路径privateKeyPath: crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/keystore/priv_sk# 访问的组织名mspid: Org1MSP# 用户名username: user1# 通道名字channelName: mychannel# 链码名字contractName: mycc

四、连接合约

分别构建网关、通道和合约的Bean对象，代码如下：

/*** 连接网关*/
@Bean
public Gateway connectGateway() throws IOException, InvalidKeyException, CertificateException {//使用org1中的user1初始化一个网关wallet账户用于连接网络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));//根据connection.json 获取Fabric网络连接对象Gateway.Builder builder = Gateway.createBuilder().identity(wallet, username).networkConfig(Paths.get(this.networkConfigPath));//连接网关return builder.connect();
}/*** 获取通道*/
@Bean
public Network network(Gateway gateway) {return gateway.getNetwork(this.channelName);
}/*** 获取合约*/
@Bean
public Contract contract(Network network) {return network.getContract(this.contractName);
}

五、合约调用

创建controller类，注入Contract对象调用合约方法：

@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、测试接口

调用接口 getUser：

http://127.0.0.1:9001/getUser?userId=1

{"money": 300,"name": "zlt","userId": "1"
}

调用接口 addUser：

http://127.0.0.1:9001/addUser?userId=6&userName=test6&money=600

2ae291bb6a366b5ba01ad49e4237da8def9e9828cc2c982e8c49d4b763af0157

七、代码下载

gitee：https://gitee.com/zlt2000/my-fabric-application-java

github：https://github.com/zlt2000/my-fabric-application-java

扫码关注有惊喜！