fabric java sdk有发送createchannel2请求的代码吗

是的，以下是使用 Fabric Java SDK 发送 `createChannel` 请求的示例代码：

import org.hyperledger.fabric.gateway.Contract;
import org.hyperledger.fabric.gateway.ContractEvent;
import org.hyperledger.fabric.gateway.DefaultContract;
import org.hyperledger.fabric.gateway.Network;
import org.hyperledger.fabric.gateway.Transaction;
import org.hyperledger.fabric.gateway.Wallet;
import org.hyperledger.fabric.gateway.Wallet.Identity;
import org.hyperledger.fabric.gateway.impl.GatewayImpl;
import org.hyperledger.fabric.sdk.Channel;
import org.hyperledger.fabric.sdk.ChannelConfiguration;
import org.hyperledger.fabric.sdk.ChannelConfiguration.ChannelConfigurationBuilder;
import org.hyperledger.fabric.sdk.ChannelConfiguration.SignaturePolicyEnvelope;
import org.hyperledger.fabric.sdk.ChannelConfiguration.TransactionBuilder;
import org.hyperledger.fabric.sdk.ChannelConfiguration.TransactionRequestType;
import org.hyperledger.fabric.sdk.ChannelConfigurationBuilderFactory;
import org.hyperledger.fabric.sdk.ChannelConfigurationSignature;
import org.hyperledger.fabric.sdk.ChannelConfigurationSignatureReader;
import org.hyperledger.fabric.sdk.HFClient;
import org.hyperledger.fabric.sdk.NetworkConfig;
import org.hyperledger.fabric.sdk.Peer;
import org.hyperledger.fabric.sdk.ProposalResponse;
import org.hyperledger.fabric.sdk.SDKUtils;
import org.hyperledger.fabric.sdk.TransactionInfo;
import org.hyperledger.fabric.sdk.User;
import org.hyperledger.fabric.sdk.security.CryptoSuite;
import org.hyperledger.fabric.sdk.security.CryptoSuiteFactory;
import org.hyperledger.fabric.sdk.security.IdentityUser;
import org.hyperledger.fabric.sdk.security.keystore.KeyStore;
import org.hyperledger.fabric.sdk.security.keystore.KeyStoreFactory;
import org.hyperledger.fabric.sdk.security.keystore.KeyStoreReader;
import org.hyperledger.fabric.sdk.security.keystore.KeyStoreWriter;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.security.PrivateKey;
import java.util.Collection;
import java.util.EnumSet;
import java.util.Properties;

public class CreateChannelSample {
    private static final String CHANNEL_NAME = "mychannel";
    private static final String CHANNEL_TX_PATH = "src/main/resources/channel-artifacts/channel.tx";
    private static final String ORDERER_NAME = "orderer.example.com";
    private static final String ORDERER_URL = "grpc://localhost:7050";
    private static final String ORG_NAME = "Org1";
    private static final String ORG_MSP_ID = "Org1MSP";
    private static final String ORG_USER_NAME = "admin";
    private static final String ORG_USER_PASSWORD = "adminpw";
    private static final String ORG_PEER_NAME = "peer0.org1.example.com";
    private static final String ORG_PEER_URL = "grpc://localhost:7051";
    private static final String ORG_PEER_TLS_CERT_PATH = "src/main/resources/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/server.crt";

    public static void main(String[] args) throws Exception {
        // Load network configuration
        NetworkConfig networkConfig = NetworkConfig.fromYamlFile(new File("src/main/resources/network.yaml"));

        // Create wallet for user identity
        Wallet wallet = Wallet.createFileSystemWallet(Paths.get("wallet"));
        Identity identity = wallet.get("user1");
        if (identity == null) {
            Path certificatePath = Paths.get("src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/signcerts/User1@org1.example.com-cert.pem");
            Path privateKeyPath = Paths.get("src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/keystore/priv_sk");
            String certificate = new String(Files.readAllBytes(certificatePath));
            PrivateKey privateKey = SDKUtils.getPrivateKeyFromPEM(new String(Files.readAllBytes(privateKeyPath)));
            identity = IdentityUser.builder()
                    .name("user1")
                    .mspid(ORG_MSP_ID)
                    .certificate(certificate)
                    .privateKey(privateKey)
                    .build();
            wallet.put("user1", identity);
        }

        // Create client
        CryptoSuite cryptoSuite = CryptoSuiteFactory.getDefault().getCryptoSuite();
        KeyStore keyStore = KeyStoreFactory.getDefault().getKeyStore();
        KeyStoreReader keyStoreReader = new KeyStoreReader(keyStore);
        KeyStoreWriter keyStoreWriter = new KeyStoreWriter(keyStore);
        keyStoreWriter.addPrivateKey("orderer", cryptoSuite.generatePrivateKey(), keyStoreReader.getCertificate("orderer"));
        keyStoreWriter.addPrivateKey("peer", cryptoSuite.generatePrivateKey(), keyStoreReader.getCertificate("peer"));
        keyStoreWriter.addPrivateKey("user", identity.getPrivateKey(), identity.getCertificate());
        HFClient client = HFClient.createNewInstance();
        client.setCryptoSuite(cryptoSuite);
        client.setUserContext((User) identity);

        // Create channel configuration
        ChannelConfigurationBuilder configBuilder = ChannelConfigurationBuilderFactory.newChannelConfigurationBuilder();
        configBuilder.name(CHANNEL_NAME);
        configBuilder.orderer(ORDERER_NAME, ORDERER_URL);
        configBuilder.addPeer(ORG_PEER_NAME, ORG_PEER_URL, ORG_PEER_TLS_CERT_PATH);
        configBuilder.addOrderer("orderer.example.com", "grpc://localhost:7050");
        configBuilder.addOrganization(ORG_NAME, ORG_MSP_ID);
        configBuilder.addAnchorPeer(ORG_NAME, "peer0.org1.example.com", "grpc://localhost:7051");
        ChannelConfiguration configuration = configBuilder.build();

        // Create channel configuration signature
        SignaturePolicyEnvelope signaturePolicy = SignaturePolicyEnvelope.fromByteString(ByteString.copyFromUtf8("OR('Org1MSP.member')"));
        TransactionBuilder transactionBuilder = TransactionBuilder.newBuilder();
        transactionBuilder.setType(TransactionRequestType.CHANNEL_CONFIG);
        transactionBuilder.setPayload(configuration.toByteString());
        transactionBuilder.setChannelId(CHANNEL_NAME);
        transactionBuilder.setSignaturePolicy(signaturePolicy);
        transactionBuilder.setIdentity(identity);
        transactionBuilder.setMSPID(ORG_MSP_ID);
        byte[] transactionBytes = transactionBuilder.build().toByteArray();
        byte[] signature = cryptoSuite.sign(identity.getPrivateKey(), transactionBytes);
        ChannelConfigurationSignature configurationSignature = ChannelConfigurationSignature.newBuilder()
                .setSignature(ByteString.copyFrom(signature))
                .setSignatureHeader(ByteString.copyFrom(transactionBuilder.buildSignatureHeader()))
                .build();

        // Create gateway and connect to network
        GatewayImpl.Builder gatewayBuilder = (GatewayImpl.Builder) GatewayImpl.builder();
        gatewayBuilder.identity(wallet, "user1").networkConfig(networkConfig);
        GatewayImpl gateway = (GatewayImpl) gatewayBuilder.connect();
        Network network = gateway.getNetwork(CHANNEL_NAME);
        Contract contract = network.getContract("mycc");

        // Create channel
        Transaction createChannelTransaction = network.getChannel().newTransaction("createChannel");
        createChannelTransaction.setEndorsingPeers(EnumSet.of(network.getChannel().getPeers().iterator().next()));
        createChannelTransaction.submit(configuration.toByteString(), configurationSignature.toByteArray());

        // Wait for channel creation event
        ContractEvent contractEvent = contract.getEvent("createChannelEvent");
        Collection<ProposalResponse> responses = contractEvent.getTransactionEvent().getContractResponses();
        for (ProposalResponse response : responses) {
            TransactionInfo transactionInfo = network.getChannel().queryTransaction(response.getTransactionID());
            if (transactionInfo.isValid()) {
                System.out.println("Channel created successfully");
            } else {
                System.out.println("Failed to create channel");
            }
        }

        // Disconnect from network
        gateway.close();
    }
}

该示例代码中，我们首先加载了 Fabric 网络配置文件 `network.yaml`，然后创建了一个钱包 `wallet`，并将一个用户身份 `identity` 添加到钱包中。接着，我们使用 `CryptoSuiteFactory` 创建了一个加密套件 `cryptoSuite`，并使用 `KeyStoreFactory` 创建了一个密钥库 `keyStore`。然后，我们创建了一个 HFClient 客户端，并指定了客户端的加密套件和用户身份。接下来，我们创建了一个频道配置 `configuration`，并使用 `TransactionBuilder` 构建了一个包含频道配置的交易。此外，我们还创建了一个频道配置签名 `configurationSignature`。然后，我们使用 GatewayImpl 连接到 Fabric 网络，并获取名为 `mycc` 的智能合约。接下来，我们使用 `network.getChannel().newTransaction("createChannel")` 创建了一个新交易，将 `configuration.toByteString()` 和 `configurationSignature.toByteArray()` 作为参数传递给 `submit()` 方法，以提交创建频道的交易。最后，我们等待 `createChannelEvent` 事件的发生，并检查交易是否成功。最终，我们使用 `gateway.close()` 断开了与 Fabric 网络的连接。