Bookstore Demo Application

Background

This is a demo application for online bookstore, providing browsing, purchasing book via end user's browser etc.

It is built on top of Spring Boot framework, since Spring Boot is a great framework for building microservices quickly and easily, and also the Spring Community is very active and has a lot of great resources and outstanding solutions for common problems.

To simplify demo, here putting book service and cart service into one project.

Tech Stack

• Java 21
• Spring Boot 3.3.4
• Spring Data JPA
• Spring Event
• Hibernate
• H2 Database
• Lombok
• JUnit5
• Mockito
• Mapstruct
• Swagger UI
• Gradle 8+
• Flyway
• RFC-9457
• Version Catalog
• Checkstyle
• Spotless
• Testcontainers

Error Response

follow RFC-9457 specification to response with standard error output, it is clean and easier to align with Frontend or other integration point.

API Specification

• The api specification is generated by Swagger UI. You can access it via API Specification
• API Versioning on URL path is supported.

API Usage

• export above Api Specification into JSON file and import into Postman or other similar tools
• checkout each API and try it out
• you can also try it out via curl or other tools
• API explanation as below:

• /books/v1/: create a book with title and price etc.
• /books/v1/{id}: get a book by id, if not found then return 404.
• /books/v1/{index}/{size}: get a page of books with index and size.
• /carts/v1/book/: add a book into current user's cart, will return cart id.
• /carts/v1/{id}/book/: incr or decr a book's purchased amount from current user's cart by cart id.
• /carts/v1/books/: get all books from current user's cart.
• /checkouts/v1/summary: get a summary (total price) of current user's cart.

How to run the application?

1. Clone this repository
2. Run the following command in the root directory of the project

if you have installed Gradle in your environment, then just run:

gradle clean bootRun

otherwise, then run

./gradlew clean bootRun

How to run unit test?

1. Clone this repository
2. Run the following command in the root directory of the project

gradle clean test

otherwise, then run

./gradlew clean test

3. Test Report will be generated under

build/reports/tests/test/index.html

How to run unit test with coverage?

1. Clone this repository
2. Run the following command in the root directory of the project

gradle clean jacocoTestReport

3.Coverage report will be generated under

build/reports/jacoco/test/index.html

4.Report example as following

Actuator

http://localhost:8080/actuator http://localhost:8080/actuator/refresh http://localhost:8080/actuator/health

Redis

https://github.com/redis/lettuce/wiki/Connection-Pooling

Capabilities

• Global Exception Handler
• Entity Convertor
• Distributed Lock
• Custom Metrics
• Auto reload yaml file and refresh properties bean
• Checkstyle (https://checkstyle.sourceforge.io/google_style.html)
• Spotless https://github.com/diffplug/spotless/tree/main/plugin-gradle#requirements
• API Doc https://springdoc.org/
• Testcontainers https://testcontainers.com/guides/testing-spring-boot-rest-api-using-testcontainers/
• Native https://docs.spring.io/spring-boot/docs/3.2.3/reference/html/native-image.html

Startup time

Raw executable jar: 3.383 seconds

Unpack executable jar: 2.815 seconds (+16%)

Unpack + CDS executable jar: 1.966 seconds (+30%)

Unpack + CDS + AOT executable jar: 1.54 seconds (+21%)

GraalVM jar: 0.365 seconds (+90%)

Hey Benchmark

from ben-logs files, showing that native image outperform jvm on requests/sec.

AOT Notes

• Code generation does not support org.springframework.cloud.context.scope.refresh.RefreshScope
• in AOT, Unable to find 'record-request-start-time' in UndertowOptions