This is a Spring boot based Java backend intended to convert numbers from one number representation to another number representation. It is intended to be extended later on:
At the moment, the following number styles are supported:
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Any number format → Roman
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Roman → Any number format
This backend currently supports only number conversions up to 3,999 (MMMCMXCIX) and only supports full numbers without fractions.
A roman numeral is a number represented with letters.
| Symbol | Value |
|---|---|
I |
|
V |
|
X |
|
L |
|
C |
|
D |
|
M |
|
These letters are combined in the following order:
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Highest to lowest (left to right) → additive (XI → 11)
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If a lower number is left of a higher number → subtractive (IX → 9)
These notes are from Spring Boot to help getting started with the Spring boot framework
For further reference, please consider the following sections:
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[Official Apache Maven documentation](https://maven.apache.org/guides/index.html)
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[Spring Boot Maven Plugin Reference Guide](https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/maven-plugin/)
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[Spring Configuration Processor](https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/reference/htmlsingle/#configuration-metadata-annotation-processor)
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[Spring Web](https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/reference/htmlsingle/#boot-features-developing-web-applications)
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[Spring Data MongoDB](https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/reference/htmlsingle/#boot-features-mongodb)
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[Spring Boot DevTools](https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/reference/htmlsingle/#using-boot-devtools)
The following guides illustrate how to use some features concretely:
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[Building a RESTful Web Service](https://spring.io/guides/gs/rest-service/)
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[Serving Web Content with Spring MVC](https://spring.io/guides/gs/serving-web-content/)
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[Building REST services with Spring](https://spring.io/guides/tutorials/bookmarks/)
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[Accessing Data with MongoDB](https://spring.io/guides/gs/accessing-data-mongodb/)
Should be implemented as a SinglePageApplication (SPA). That app should allow users to enter a number into an input field and convert it into another format. Your UI should allow for converting numbers (1) from decimal to roman as well as (2) from binary to roman. The app should include a NumberConverter component that would render a UI control to toggle between conversion modes. As your co-workers will need the NumberConverter component for other use cases as well, it should be written in a generic and reusable way to allow extending it with new conversion operations (e.g., hexadecimal to roman). You do not have to implement these other use cases; but please make sure using NumberConverter in other contexts would require minimal changes to your code.
All conversions executed via the frontend should have an audit trail in the backend store. You can choose and implement any store you like, whether it is a flat file or a RDBMS (in-memory or persistent). Each audit record should include a timestamp, a type of conversion, incoming and outgoing params/results.
We are mainly interested in a way you solve this problem on a conceptual level. Therefore, we care more about code quality (cleanliness), separation of concerns and maintainability than about a polished UI design. Try applying OOP principles such as Dependency Injection thoughtfully.
We want you to implement this application using Java/Spring Boot as a self-contained app (with all the dependencies baked into one jar file) with Typescript/Javascript React/Angular (whatever you’re most comfortable with) frontend. Please do not use any external libraries to perform the conversions.