Hyperledger Fabric架构及Java SDK实现

作者: 小蜗牛爬楼梯 | 来源:发表于2020-06-13 18:31 被阅读0次

Hyperledger Fabric 整理体系：

Fabric 整体架构和交易流程

Fabric Samples 在Mac部署和运行

Fabric Samples 运行日志记录

Fabric Samples BYFN 命令行详解

Fabric Samples 运行时架构和Java客户端具体实现

image

各项解释如下：

APP：代表一个客户端或者SDK，作用是创建交易并获取到足够的背书之后向Orderer排序服务节点提交交易请求。（peer和orderer提供了gRPC远程访问接口，供客户端调用）
CA：负责对网络中所有证书进行管理，提供标准的KPI服务
MSP：为客户端和peer提供证书的系统抽象组件
Channel：通道提供了一种通讯机制，将peers和orderer连接在一起，形成一个具有保密性的通讯链路；将一个大网络分割成不同私有子网，进行数据隔离
Orderer：对客户端提交的交易请求进行排序，之后生成区块广播给通道内所有peer节点
Org1：代表联盟中的某-组织
Peer：表示组织中的节点；peer节点以区块的形式从orderer排序服务节点接收有序状态更新，维护状态和账本。fabric中Peer节点可划分如下：
1. Endorsing Peer：根据指定的策略调用智能合约，对结果进行背书，返回提案相应到客户端
2. Committing Peer：验证数据并保存到账本中
3. Anchor Peer：跨组织通讯
4. Leading Peer：做为组织内所有节点的代表连接到Orderer排序服务节点，将从排序服务节点接收到的批量区块广播给组织内的其他节点
Chaincode：链码，部署在fabric的网络节点中，独立运行在具有安全特性的受保护容器中，以gRPC协议与相应Peer节点进行通讯，提供相应的API与账本数据进行交互
Ledger：有排序服务构建的一个全部有序的交易哈希链块，保存在所有的Peer节点中。

Java SDK提供了一种执行用户链码，查询块数据，在通道进行交易及模拟事件的方式。
此模式下，区块链网络由两个组织，每个组织包含两个结点，和一个order服务；将展示怎样创建和初始化通道，安装和部署链码，和执行调用和查询操作。

image

基本原理

在fabric区块链中，应用通过结点RPC协议接口访问链码。

image

类似于Shim API对链码通讯协议的封装，JavaSDK提供了对结点RPC协议接口封装，其入口类为HFClient；对链码的交易和查询操作则封装在channel类中。

image

简单实例

实现User接口
HFClient访问fabric网络身份使用User接口实现。
一个用户的身份由它的证书来标识的，同时交易还需要证书对应的私钥，因此LocalUser的核心逻辑就是利用指定的证书和私钥PEM文件满足User接口的要求。
image
访问链码
创建HFClient实例，然后获取通道对象，就可以查询链码或者提交链码交易。

命令行操作： hyperledger fabric byfn up详解

代码具体实现

运行fabric-samples中fabcar，创建区块链网络
新建Java工程，引入fabric-gateway-java，实现具体实现
pom.xml

    <repositories>
        <repository>
            <id>oss-sonatype</id>
            <name>OSS Sonatype</name>
            <url>https://oss.sonatype.org/content/repositories/snapshots</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>org.hyperledger.fabric</groupId>
            <artifactId>fabric-gateway-java</artifactId>
            <version>1.4.1-SNAPSHOT</version>
        </dependency>
    </dependencies>

加入Admins角色：

public class EnrollAdmin {

    static {
        System.setProperty("org.hyperledger.fabric.sdk.service_discovery.as_localhost", "true");
    }

    public static void main(String[] args) throws Exception {

        // Create a CA client for interacting with the CA.
        Properties props = new Properties();
        props.put("pemFile",
            "/Users/macserver/Documents/BlockChain/src/github.com/hyperledger/fabric-samples/first-network/crypto-config/peerOrganizations/org1.example.com/ca/ca.org1.example.com-cert.pem");
        props.put("allowAllHostNames", "true");
        HFCAClient caClient = HFCAClient.createNewInstance("https://localhost:7054", props);
        CryptoSuite cryptoSuite = CryptoSuiteFactory.getDefault().getCryptoSuite();
        caClient.setCryptoSuite(cryptoSuite);

        // Create a wallet for managing identities
        Wallet wallet = Wallet.createFileSystemWallet(Paths.get("wallet"));

        // Check to see if we've already enrolled the admin user.
        boolean adminExists = wallet.exists("admin");
        if (adminExists) {
            System.out.println("An identity for the admin user \"admin\" already exists in the wallet");
            return;
        }

        // Enroll the admin user, and import the new identity into the wallet.
        final EnrollmentRequest enrollmentRequestTLS = new EnrollmentRequest();
        enrollmentRequestTLS.addHost("localhost");
        enrollmentRequestTLS.setProfile("tls");
        Enrollment enrollment = caClient.enroll("admin", "adminpw", enrollmentRequestTLS);
        Identity user = Identity.createIdentity("Org1MSP", enrollment.getCert(), enrollment.getKey());
        wallet.put("admin", user);
        System.out.println("Successfully enrolled user \"admin\" and imported it into the wallet");
    }
}

加入user1角色：

public class RegisterUser {

    static {
        System.setProperty("org.hyperledger.fabric.sdk.service_discovery.as_localhost", "true");
    }

    public static void main(String[] args) throws Exception {

        // Create a CA client for interacting with the CA.
        Properties props = new Properties();
        props.put("pemFile",
            "/Users/macserver/Documents/BlockChain/src/github.com/hyperledger/fabric-samples/first-network/crypto-config/peerOrganizations/org1.example.com/ca/ca.org1.example.com-cert.pem");
        props.put("allowAllHostNames", "true");
        HFCAClient caClient = HFCAClient.createNewInstance("https://localhost:7054", props);
        CryptoSuite cryptoSuite = CryptoSuiteFactory.getDefault().getCryptoSuite();
        caClient.setCryptoSuite(cryptoSuite);

        // Create a wallet for managing identities
        Wallet wallet = Wallet.createFileSystemWallet(Paths.get("wallet"));

        // Check to see if we've already enrolled the user.
        boolean userExists = wallet.exists("user1");
        if (userExists) {
            System.out.println("An identity for the user \"user1\" already exists in the wallet");
            return;
        }

        userExists = wallet.exists("admin");
        if (!userExists) {
            System.out.println("\"admin\" needs to be enrolled and added to the wallet first");
            return;
        }

        Identity adminIdentity = wallet.get("admin");
        User admin = new User() {

            @Override
            public String getName() {
                return "admin";
            }

            @Override
            public Set<String> getRoles() {
                return null;
            }

            @Override
            public String getAccount() {
                return null;
            }

            @Override
            public String getAffiliation() {
                return "org1.department1";
            }

            @Override
            public Enrollment getEnrollment() {
                return new Enrollment() {

                    @Override
                    public PrivateKey getKey() {
                        return adminIdentity.getPrivateKey();
                    }

                    @Override
                    public String getCert() {
                        return adminIdentity.getCertificate();
                    }
                };
            }

            @Override
            public String getMspId() {
                return "Org1MSP";
            }

        };

        // Register the user, enroll the user, and import the new identity into the wallet.
        RegistrationRequest registrationRequest = new RegistrationRequest("user1");
        registrationRequest.setAffiliation("org1.department1");
        registrationRequest.setEnrollmentID("user1");
        String enrollmentSecret = caClient.register(registrationRequest, admin);
        Enrollment enrollment = caClient.enroll("user1", enrollmentSecret);
        Identity user = Identity.createIdentity("Org1MSP", enrollment.getCert(), enrollment.getKey());
        wallet.put("user1", user);
        System.out.println("Successfully enrolled user \"user1\" and imported it into the wallet");
    }

}

客户端：查询及添加新数据

public class ClientApp {

    static {
        System.setProperty("org.hyperledger.fabric.sdk.service_discovery.as_localhost", "true");
    }

    public static void main(String[] args) throws Exception {
        // Load a file system based wallet for managing identities.
        Path walletPath = Paths.get("wallet");
        Wallet wallet = Wallet.createFileSystemWallet(walletPath);

        // load a CCP
        Path networkConfigPath = Paths.get("/Users/macserver/Documents/BlockChain/src/github.com/hyperledger/fabric-samples/fabcar", "..", "first-network", "connection-org1.yaml");

        Gateway.Builder builder = Gateway.createBuilder();
        builder.identity(wallet, "user1").networkConfig(networkConfigPath).discovery(true);

        // create a gateway connection
        try (Gateway gateway = builder.connect()) {

            // get the network and contract
            Network network = gateway.getNetwork("mychannel");
            Contract contract = network.getContract("fabcar");

            byte[] result;

            result = contract.evaluateTransaction("queryAllCars");
            System.out.println(new String(result));

            contract.submitTransaction("createCar", "CAR10", "VW", "Polo", "Grey", "Mary");

            result = contract.evaluateTransaction("queryCar", "CAR10");
            System.out.println(new String(result));

            contract.submitTransaction("changeCarOwner", "CAR10", "Archie");

            result = contract.evaluateTransaction("queryCar", "CAR10");
            System.out.println(new String(result));
        }
    }

}

实现方式二

如果跳过gateway，直接使用fabric-sdk-java，数据查询-实现代码如下：

private static void queryAllCars() throws Exception {
        HFClient hfClient = HFClient.createNewInstance();

        CryptoSuite cryptoSuite = CryptoSuiteFactory.getDefault().getCryptoSuite();
        hfClient.setCryptoSuite(cryptoSuite);

        Enrollment enrollment = new X509Enrollment(getPrivateKey(Paths.get("wallet/user1/user1-priv")), getCertificate(certificate_user1));
        User user = new User() {
            @Override
            public String getName() {
                return "gateway";
            }

            @Override
            public Set<String> getRoles() {
                return Collections.emptySet();
            }

            @Override
            public String getAccount() {
                return "";
            }

            @Override
            public String getAffiliation() {
                return "";
            }

            @Override
            public Enrollment getEnrollment() {
                return enrollment;
            }

            @Override
            public String getMspId() {
                return "Org1MSP";
            }
        };

        hfClient.setUserContext(user);

        NetworkConfig networkConfig = NetworkConfig.fromYamlFile(new File(path + "first-network/connection-org1.yaml"));

        Channel channel = hfClient.newChannel("mychannel");

        List<String> peerNames = networkConfig.getClientOrganization().getPeerNames();
        for (String name : peerNames) {
            String url = networkConfig.getPeerUrl(name);
            Properties props = networkConfig.getPeerProperties(name);
            System.err.println("xxxxxxxxx：" + name + "..." + url);
            Peer peer = hfClient.newPeer(name, url, props);

            Channel.PeerOptions peerOptions = Channel.PeerOptions.createPeerOptions().setPeerRoles(EnumSet.allOf(Peer.PeerRole.class));
            channel.addPeer(peer, peerOptions);
        }

        channel.initialize();

        QueryByChaincodeRequest request = QueryByChaincodeRequest.newInstance(user);

        request.setChaincodeID(getChaincodeId("fabcar"));
        request.setFcn("queryAllCars");
        request.setArgs("");

        Collection<ProposalResponse> responses = channel.queryByChaincode(request, Collections.singletonList(channel.getPeers().iterator().next()));
        ProposalResponse response = responses.iterator().next();
        byte[] bytes = response.getChaincodeActionResponsePayload();

        System.err.println("xxxxxxx：" + new String(bytes));
    }

    private static String getCertificate(String certificate) {
        BufferedReader certReader = new BufferedReader(new StringReader(certificate));
        return certReader.lines().collect(Collectors.joining("\n", "", "\n"));
    }

    private static PrivateKey getPrivateKey(Path pemFile) {
        try {
            PEMParser parser = new PEMParser(Files.newBufferedReader(pemFile));
            Object key = parser.readObject();
            JcaPEMKeyConverter converter = new JcaPEMKeyConverter();
            return converter.getPrivateKey((PrivateKeyInfo) key);
        } catch (IOException e) {
            System.err.println("private key 获取失败");
            return null;
        }
    }

    private static ChaincodeID getChaincodeId(String chaincodeId) {
        return ChaincodeID.newBuilder()
                .setName(chaincodeId)
                .build();
    }

作者：谷雨_时
链接：https://www.jianshu.com/p/d2c796849b42
来源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

Hyperledger Fabric架构及Java SDK实现

基本原理

简单实例

命令行操作： hyperledger fabric byfn up详解

代码具体实现

实现方式二

相关文章

网友评论

延伸阅读

深度阅读

栏目导航

热点阅读

超级账本HyperLeder

初见

Hyperledger Fabric架构及Java SDK实现

基本原理

简单实例

命令行操作： hyperledger fabric byfn up详解

代码具体实现

实现方式 二

相关文章

网友评论

延伸阅读

深度阅读

栏目导航

热点阅读

超级账本HyperLeder

初见

实现方式二