如何在HyperLedger Fabric中将字节数组传递给chaincode

Question

I am writing a chaincode to run on fabric, and this is code piece of 'fabcar.go', the sample of fabric chaincode.

I notice that I can pass a []string parameters from my java application using fabric-java-sdk, but I have problems when I try to pass some []byte parameters form my application.

I ve tried other funcs like

func (stub *ChaincodeStub) GetArgs() [][]byte
func (stub *ChaincodeStub) GetArgsSlice() ([]byte, error)
func (stub *ChaincodeStub) GetBinding() ([]byte, error)

but still do not know how to do it.

func (s *SmartContract) Invoke(APIstub shim.ChaincodeStubInterface) sc.Response {
        // Retrieve the requested Smart Contract function and arguments
        function, args := APIstub.GetFunctionAndParameters()
        // Route to the appropriate handler function to interact with the ledger appropriately
        if function == "queryCar" {
            return s.queryCar(APIstub, args)
        ...

Did I miss anything or it's not supported now? help me Please!

Answer 1

Turns out to be that all args are passed in type of [][]byte to chaincode. In the definition is

args           [][]byte

in

type ChaincodeStub struct {
    TxID           string
    ChannelId      string
    chaincodeEvent *pb.ChaincodeEvent
    args           [][]byte
    handler        *Handler
    signedProposal *pb.SignedProposal
    proposal       *pb.Proposal

    // Additional fields extracted from the signedProposal
    creator   []byte
    transient map[string][]byte
    binding   []byte

    decorations map[string][]byte
}

It's just the function GetFunctionAndParameters() wrapper those bytes to string.

// GetFunctionAndParameters documentation can be found in interfaces.go
func (stub *ChaincodeStub) GetFunctionAndParameters() (function string, params []string) {
    allargs := stub.GetStringArgs()
    function = ""
    params = []string{}
    if len(allargs) >= 1 {
        function = allargs[0]
        params = allargs[1:]
    }
    return
}

the returned value 'function' is actually string(allargs[0]), and the rest of the args will be in allargs[1:].