java rfc内表传参 rfc接口 java

fabric是一个分布式账本平台，它提供了一种简单的方式来构建区块链应用程序。如果想要在fabric中使用RS纠删码，可以按照以下步骤进行整合：

• 首先，需要在fabric中定义一个新的链码（chaincode）来实现RS纠删码的逻辑。可以使用Java编写链码，然后在fabric网络中部署它。
• 在链码中，需要使用Java库来实现RS纠删码的算法。可以使用开源库，如Jerasure或ErasureCode，也可以自己实现算法。
• 在链码中，需要定义一个函数来对数据进行编码和解码。编码函数将原始数据拆分为多个数据块，并使用RS纠删码算法生成一些冗余数据块。解码函数将数据块和冗余数据块合并以恢复原始数据。
• 最后，在应用程序中调用链码中的编码和解码函数来实现RS纠删码功能。可以使用fabric的Java SDK来访问链码。

整合RS纠删码需要一定的编程技能和算法知识。如果不熟悉这些知识，建议先学习相关的课程和文献，然后再尝试在fabric中实现RS纠删码。

以下是一个简单的示例，演示如何在fabric中使用Java实现RS纠删码。

1、首先，需要在fabric中定义一个新的链码。可以使用Java编写链码，例如：

public class RSEncodingChaincode implements Chaincode {
    @Override
    public Response init(ChaincodeStub stub) {
        return newSuccessResponse();
    }

    @Override
    public Response invoke(ChaincodeStub stub) {
        String func = stub.getFunction();
        List<String> args = stub.getParameters();

        if ("encode".equals(func)) {
            return encode(stub, args);
        } else if ("decode".equals(func)) {
            return decode(stub, args);
        } else {
            return newErrorResponse("Invalid function name");
        }
    }

    private Response encode(ChaincodeStub stub, List<String> args) {
        // TODO: Implement RS encoding algorithm
        return newSuccessResponse();
    }

    private Response decode(ChaincodeStub stub, List<String> args) {
        // TODO: Implement RS decoding algorithm
        return newSuccessResponse();
    }
}

2、在链码中，需要使用Java库来实现RS纠删码的算法。可以使用开源库，如Jerasure或ErasureCode，也可以自己实现算法。例如，使用Jerasure库：

import org.apache.commons.codec.binary.Base64;
import org.koka.erasure.Encoder;

private Response encode(ChaincodeStub stub, List<String> args) {
    String data = args.get(0);
    int k = Integer.parseInt(args.get(1));
    int m = Integer.parseInt(args.get(2));

    byte[][] dataBlocks = splitData(data, k);
    byte[][] parityBlocks = new byte[m][dataBlocks[0].length];

    Encoder encoder = new Encoder(k, m);
    encoder.encode(dataBlocks, parityBlocks);

    List<String> blocks = new ArrayList<>();
    for (byte[] block : dataBlocks) {
        blocks.add(Base64.encodeBase64String(block));
    }
    for (byte[] block : parityBlocks) {
        blocks.add(Base64.encodeBase64String(block));
    }

    return newSuccessResponse(blocks);
}

private Response decode(ChaincodeStub stub, List<String> args) {
    List<String> blocks = args.subList(0, Integer.parseInt(args.get(1)) + Integer.parseInt(args.get(2)));
    int k = Integer.parseInt(args.get(1));
    int m = Integer.parseInt(args.get(2));

    byte[][] dataBlocks = new byte[k][];
    byte[][] parityBlocks = new byte[m][];
    int i = 0;
    for (String block : blocks) {
        if (i < k) {
            dataBlocks[i] = Base64.decodeBase64(block);
        } else {
            parityBlocks[i - k] = Base64.decodeBase64(block);
        }
        i++;
    }

    Encoder encoder = new Encoder(k, m);
    int[] erasures = encoder.decode(dataBlocks, parityBlocks);

    if (erasures != null) {
        return newErrorResponse("Failed to decode data");
    }

    byte[] data = joinData(dataBlocks);
    return newSuccessResponse(Base64.encodeBase64String(data));
}

private byte[][] splitData(String data, int k) {
    byte[] bytes = data.getBytes();
    int n = (bytes.length + k - 1) / k;
    byte[][] blocks = new byte[k][n];
    for (int i = 0; i < bytes.length; i++) {
        blocks[i % k][i / k] = bytes[i];
    }
    return blocks;
}

private byte[] joinData(byte[][] blocks) {
    int n = blocks[0].length;
    byte[] bytes = new byte[blocks.length * n];
    for (int i = 0; i < bytes.length; i++) {
        bytes[i] = blocks[i % blocks.length][i / blocks.length];
    }
    return bytes;
}

3、在链码中，需要定义一个函数来对数据进行编码和解码。编码函数将原始数据拆分为多个数据块，并使用RS纠删码算法生成一些冗余数据块。解码函数将数据块和冗余数据块合并以恢复原始数据。例如：

private Response encode(ChaincodeStub stub, List<String> args) {
    String data = args.get(0);
    int k = Integer.parseInt(args.get(1));
    int m = Integer.parseInt(args.get(2));

    byte[][] dataBlocks = splitData(data, k);
    byte[][] parityBlocks = new byte[m][dataBlocks[0].length];

    Encoder encoder = new Encoder(k, m);
    encoder.encode(dataBlocks, parityBlocks);

    List<String> blocks = new ArrayList<>();
    for (byte[] block : dataBlocks) {
        blocks.add(Base64.encodeBase64String(block));
    }
    for (byte[] block : parityBlocks) {
        blocks.add(Base64.encodeBase64String(block));
    }

    return newSuccessResponse(blocks);
}

private Response decode(ChaincodeStub stub, List<String> args) {
    List<String> blocks = args.subList(0, Integer.parseInt(args.get(1)) + Integer.parseInt(args.get(2)));
    int k = Integer.parseInt(args.get(1));
    int m = Integer.parseInt(args.get(2));

    byte[][] dataBlocks = new byte[k][];
    byte[][] parityBlocks = new byte[m][];
    int i = 0;
    for (String block : blocks) {
        if (i < k) {
            dataBlocks[i] = Base64.decodeBase64(block);
        } else {
            parityBlocks[i - k] = Base64.decodeBase64(block);
        }
        i++;
    }

    Encoder encoder = new Encoder(k, m);
    int[] erasures = encoder.decode(dataBlocks, parityBlocks);

    if (erasures != null) {
        return newErrorResponse("Failed to decode data");
    }

    byte[] data = joinData(dataBlocks);
    return newSuccessResponse(Base64.encodeBase64String(data));
}

private byte[][] splitData(String data, int k) {
    byte[] bytes = data.getBytes();
    int n = (bytes.length + k - 1) / k;
    byte[][] blocks = new byte[k][n];
    for (int i = 0; i < bytes.length; i++) {
        blocks[i % k][i / k] = bytes[i];
    }
    return blocks;
}

private byte[] joinData(byte[][] blocks) {
    int n = blocks[0].length;
    byte[] bytes = new byte[blocks.length * n];
    for (int i = 0; i < bytes.length; i++) {
        bytes[i] = blocks[i % blocks.length][i / blocks.length];
    }
    return bytes;
}

4、最后，在应用程序中调用链码中的编码和解码函数来实现RS纠删码功能。例如：

public static void main(String[] args) throws Exception {
    HFClient client = HFClient.createNewInstance();
    client.setCryptoSuite(CryptoSuite.Factory.getCryptoSuite());

    User user = new UserImpl();
    client.setUserContext(user);

    Channel channel = client.newChannel("mychannel");
    channel.addPeer(client.newPeer("peer0.org1.example.com", "grpc://localhost:7051"));
    channel.addOrderer(client.newOrderer("orderer.example.com", "grpc://localhost:7050"));
    channel.initialize();

    ChaincodeID ccId = ChaincodeID.newBuilder().setName("rs-encoding").build();

    String data = "hello world";
    int k = 3;
    int m = 2;

    TransactionProposalRequest request = client.newTransactionProposalRequest();
    request.setChaincodeID(ccId);
    request.setFcn("encode");
    request.setArgs(Arrays.asList(data, String.valueOf(k), String.valueOf(m)));

    Collection<ProposalResponse> responses = channel.sendTransactionProposal(request);
    for (ProposalResponse response : responses) {
        if (response.getStatus() == ProposalResponse.Status.SUCCESS) {
            List<String> blocks = Arrays.asList(response.getChaincodeActionResponsePayload().toStringUtf8().split("\\s+"));
            System.out.println("Encoded blocks: " + blocks);
        } else {
            System.out.println("Failed to encode data: " + response.getMessage());
        }
    }

    List<String> blocks = Arrays.asList("block1", "block2", "block3", "block4", "block5");
    request = client.newTransactionProposalRequest();
    request.setChaincodeID(ccId);
    request.setFcn("decode");
    request.setArgs(blocks);

    responses = channel.sendTransactionProposal(request);
    for (ProposalResponse response : responses) {
        if (response.getStatus() == ProposalResponse.Status.SUCCESS) {
            String result = response.getChaincodeActionResponsePayload().toStringUtf8();
            System.out.println("Decoded data: " + result);
        } else {
            System.out.println("Failed to decode data: " + response.getMessage());
        }
    }
}

这是一个简单的示例，演示了如何在fabric中使用Java实现RS纠删码。实际应用中，可能需要更复杂的算法和更完整的功能。