This repository demonstrates various features of Corda.

To deploy different CorDapps:

1. Change the configurations in settings.gradle to include desired projects.
2. Change the 'app' property in gradle.properties.
3. Run ./gradlew jar to generate new jar files
4. Run ./update $app to copy these files to Node cordapp directories.

The database provided by Corda nodes can store both on-ledger data and off-ledger data. Database can be accessed via native jdbc connection or JPA.

States can be made queryable by implementing QueryableState interface. Off-ledger data storage needs to be registered with hibernate.

To use the Corda node built-in database, you need to subclass MappedSchema, which allows Corda knows what you want to do to the database.

Your created schema is required to belong to a schema family, which allows smooth future upgrade. Also required are various tables and constraints (hence Schema).

The way it works is that during the node start-up, Corda will read information defined in your cordapps and update database (migration) accordingly. Database migration currently (it seems) must be done manually by running java -jar corda.jar run-migration-scripts --core-schemas --app-schemas --allow-hibernate-to-manage-app-schema or else node start-up would fail.

QueryableState is a convenient feature in that it automates the process of creating new entries when new states are recorded. To implement it, you need to define two methods: supportedSchema() which tells Corda which schema this state will be recorded in, and generateMappedObject which maps the State object to Entity object based on the given schema.

An account is a LinearState, associated with arbitrary key-pairs certified by the host node. Transactions belonging to an account are signed by the node using one of the account's keys.