Creating a contract

We are now ready to start implementing our contracts. We will focus on code examples from ExportLicenseContract implemented in Java and TradeContract implemented in Node.js.

Full documentation of Java and Node.js Contract APIs are available at:

• https://hyperledger.github.io/fabric-chaincode-java/
• https://hyperledger.github.io/fabric-chaincode-node/master/api/index.html

The contract interface

Every contract must implement the ContractInterface, whose methods are called in response to the received transaction proposals.

In Java, the ContractInterface is defined in the org.hyperledger.fabric.contract package and shown in the following code:

package org.hyperledger.fabric.contract;
public interface ContractInterface {
  default Context createContext(final ChaincodeStub stub);
  default void unknownTransaction(final Context ctx);
  default void beforeTransaction(final Context ctx);
  default void afterTransaction...