This is an exercise of Domain Driven Design and Spring Boot techniques.

The program manages books and readers of a library. Each reader can borrow up to three books, and one book can only be borrowed by one reader a time. When a book has been borrowed five times, it is marked as a 'hot' book. The admin can register new books and new readers. The admin can check who is holding a book and what books a reader has currently borrowed.

There are two domain models: Book and Reader.

This application uses:

• Domain Driven Design
• CQRS
• Event Sourcing
• Spring Boot
• Axon Framework
• RESTful service
• MongoDB

$ mvn package

net start MongoDB

java -jar target/book-library-saga-0.1.0.jar

curl -X POST -d '{"title":"Lord of the Rings", "author": "J. R. R. Tolkien"}' -H "Content-Type:application/json" http://localhost:8080/api/books curl -X POST -d '{"title":"The Importance of Living", "author": "Lin Yutang"}' -H "Content-Type:application/json" http://localhost:8080/api/books curl -X POST -d '{"title":"War and Peace", "author": "Leo Tolstoy"}' -H "Content-Type:application/json" http://localhost:8080/api/books

curl -X POST -d '{"name":"John Smith"}' -H "Content-Type:application/json" http://localhost:8080/api/readers curl -X POST -d '{"name":"Tom Hanks"}' -H "Content-Type:application/json" http://localhost:8080/api/readers

curl http://localhost:8080/api/books

curl http://localhost:8080/api/readers

curl -X POST -d '{"bookId":"3f7bf042-489a-4d5a-b0cb-ba62bf71ae32"}' -H "Content-Type:application/json" http://localhost:8080/api/readers/a5704803-ec72-4748-9453-8b7ac40674cf/borrow

curl -X POST -d '{"bookId":"dd6985cf-50b6-44b4-9cea-03c1770cb049"}' -H "Content-Type:application/json" http://localhost:8080/api/readers/a5704803-ec72-4748-9453-8b7ac40674cf/borrow

curl http://localhost:8080/api/readers/a5704803-ec72-4748-9453-8b7ac40674cf/return

> mongo

> show dbs > use axonframework switched to db axonframework

> show collections

domainevents system.indexes

> db.domainevents.find()

This version is just a rough sketch. Still lots to do.

What is an aggregate? http://cqrs.nu/Faq/aggregates

How You Can Implement Aggregates and Domain Entities Effectively in Domain Models https://www.youtube.com/watch?v=oFPbEi2463c&list=PLzsUBUx6tYGDmQEoi8i86eUar7moANEDS