May org.json.JSONObject used in org.hyperledger.fabric.contract.execution.JSONTransactionSerializer lead submit payloads not matching?

[8f235831]

When I call a submit method from application via gateway, I received an Exception below.

Caused by: org.hyperledger.fabric.client.EndorseException: io.grpc.StatusRuntimeException: ABORTED: failed to collect enough transaction endorsements, see attached details for more info
        at org.hyperledger.fabric.client.GatewayClient.endorse(GatewayClient.java:74)
        at org.hyperledger.fabric.client.ProposalImpl.endorse(ProposalImpl.java:76)
        at org.hyperledger.fabric.client.Proposal.endorse(Proposal.java:64)
        at pers.u8f23.fabric.app.api.AbstractAssetContractSubmit.createAsset(AbstractAssetContractSubmit.java:13)
        at pers.u8f23.fabric.app.Main.chaincodeOperations(Main.java:84)
        at pers.u8f23.fabric.app.Main.main(Main.java:65)
Caused by: io.grpc.StatusRuntimeException: ABORTED: failed to collect enough transaction endorsements, see attached details for more info
        at io.grpc.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:268)
        at io.grpc.stub.ClientCalls.getUnchecked(ClientCalls.java:249)
        at io.grpc.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:167)
        at org.hyperledger.fabric.protos.gateway.GatewayGrpc$GatewayBlockingStub.endorse(GatewayGrpc.java:455)
        at org.hyperledger.fabric.client.GatewayClient.endorse(GatewayClient.java:72)
        ... 5 more

Detail message attached to this Exception is ProposalResponsePayloads do not match.

Returned type is a generic class. Both the generic type and the type argument are defined as type in fabric demo .

public interface AbstractAssetContractSubmit {
  Response<Asset> createAsset(Context context, String value);

  Response<Void> deleteAsset(Context context, String assetId);

  Response<Void> updateAsset(Context context, String assetId, String value);
}

@DataType
public final class Response<T> {
  @Property
  private final T body;

  @Property
  private final int code;

  @Property
  private final String msg;

  public Response(@JsonProperty("body") T body, @JsonProperty("code") int code,
      @JsonProperty("msg") String msg) {
    this.body = body;
    this.code = code;
    this.msg = msg;
  }

  public T getBody() {
    return this.body;
  }

  public int getCode() {
    return this.code;
  }

  public String getMsg() {
    return this.msg;
  }
}

@DataType
public final class Asset {
  @Property
  private final String id;

  @Property
  private final String creatorId;

  @Property
  private final String ownerId;

  @Property
  private final long createTime;

  @Property
  private final long lastTransferTime;

  @Property
  private final long lastUpdateTime;

  @Property
  private final String assetValue;

  public Asset(@JsonProperty("id") String id, @JsonProperty("creatorId") String creatorId,
      @JsonProperty("ownerId") String ownerId, @JsonProperty("createTime") long createTime,
      @JsonProperty("lastTransferTime") long lastTransferTime,
      @JsonProperty("lastUpdateTime") long lastUpdateTime,
      @JsonProperty("assetValue") String assetValue) {
    this.id = id;
    this.creatorId = creatorId;
    this.ownerId = ownerId;
    this.createTime = createTime;
    this.lastTransferTime = lastTransferTime;
    this.lastUpdateTime = lastUpdateTime;
    this.assetValue = assetValue;
  }

  public String getId() {
    return this.id;
  }

  public String getCreatorId() {
    return this.creatorId;
  }

  public String getOwnerId() {
    return this.ownerId;
  }

  public long getCreateTime() {
    return this.createTime;
  }

  public long getLastTransferTime() {
    return this.lastTransferTime;
  }

  public long getLastUpdateTime() {
    return this.lastUpdateTime;
  }

  public String getAssetValue() {
    return this.assetValue;
  }
}

Does this chaincode api support java generic type as method return type?
Anyone is welcome to answer this question.

[8f235831]

I found below codes from line 72 of org.hyperledger.fabric.contract.execution.JSONTransactionSerializer .

// at this point we can assert that the value is
// representing a complex data type
// so we can get this from
// the type registry, and get the list of propertyNames
// it should have
final DataTypeDefinition dtd = this.typeRegistry.getDataType(ts);
final Set<String> keySet = dtd.getProperties().keySet();
final String[] propNames = keySet.toArray(new String[keySet.size()]);


// Note: whilst the current JSON library does pretty much
// everything is required, this part is hard.
// we want to create a JSON Object based on the value,
// with certain property names.


// Based on the constructors available we need to have a two
// step process, create a JSON Object, then create the object
// we really want based on the propNames
final JSONObject obj = new JSONObject(new JSONObject(value), propNames);
buffer = obj.toString().getBytes(UTF_8);

Those codes seem to be used to serializer complex objects returned by chaincode methods. The given value is processed by org.json.JSONObject, which using java.util.HashMap to obtain key-value pairs and is not sure to make pairs ordered by fixed sequence. I suspect this is a bug.

[bestbeforetoday]

What logs do you see from the Gateway peer? The logs there should give you a breakdown of what the mismatch was between responses.

[bestbeforetoday]

I have had a quick look through the implementation and I suspect that you are correct about the built-in JSON serializer not ensuring consistent field ordering in JSON objects. Both the JSON org.json serializer and the fabric-chaincode-shim TypeSchema use unordered maps to store fields.

As a workaround, I would suggest using an alternative serialization solution, such as Jackson with its @JsonPropertyOrder annotation. You could either do the serialization of transaction function return values explicitly in your smart contract code, and declare the transaction function as returning a String, or provide your own serializer implementation that does the same.