LandTitleContract.java

public class LandTitleContract implements Contract {
    // This is used to identify our contract when building a transaction.
    public static final String ID = "net.corda.c5.sample.landregistry.LandContract";

    // A transaction is valid if the verify() function of the contract of all the transaction's input and output states
    // does not throw an exception.
    @Override
    public void verify(@NotNull LedgerTransaction tx) {
        // Implement your contract validation logic here.
    }

    // Used to indicate the transaction's intent.
    public interface Commands extends CommandData {
        //In our hello-world app, We will only have one command.
        class Issue implements Commands {}
        class Transfer implements Commands {}
    }
}