Create a blockchain data object operation to use a blockchain data object in a mapping.
You can create a read operation to use as a source in a mapping or to look up data on the blockchain. You can create a write operation to use as a target in a mapping. When you run the mapping, the Spark engine uses the transactions in the data object operation to send the appropriate HTTP requests to the REST web service that exposes the blockchain.
Requests and responses use hierarchical data in JSON format.