Loan Inquiry Application

A simple loan inquiry application which is assigned as GittiGidiyor Java-Spring Bootcamp graduation criteria. It is composed of three microservices: Findex Inquiry Service, Loan Application Service and SMS Service. All the three microservices communicate with each other through Spring Cloud Gateway and registered to Eureka Service Registry. For the visual representation of operations, I have built a simple UI with Spring-Thymeleaf.

Table of Contents

• Technologies
• Installing
  • Maven
  • Docker
• Usage
  • Loan Application Service
  • Findex Inquiry Service
  • SMS Service
  • Loan Application UI
• TODO
• Versions
• Contributing

Technologies

• OpenJDK 11
• Maven
• Spring Data JPA
• Spring Cloud Gateway
• Eureka Service Registry
• SpringFox Swagger 2
• Lombok
• JIB
• Thymeleaf

Installing

Can be installed and run as:

Maven

1. Clone the application

git clone https://github.com/113-GittiGidiyor-Java-Spring-Bootcamp/gittigidiyor-graduation-project-rhancav

2. Go to the project directory

cd gittigidiyor-graduation-project-rhancav

3. Run

mvnw spring-boot:run

Docker

1. Clone the application

git clone https://github.com/113-GittiGidiyor-Java-Spring-Bootcamp/gittigidiyor-graduation-project-rhancav

2. Go to the project directory

cd gittigidiyor-graduation-project-rhancav

3. Run

docker-compose up

Usage

The main requirement for the project was that the consumer would be able to apply for a loan(optionally through UI) with their forename, surname, identification number and phone. Then the eligibility for the consumer would be calculated server-side, and the result would be shown to the consumer and then persisted to database for later queries. Along with that, an SMS notification would be sent to the consumer. It was not necessary to go with microservice architecture and if we give it a second thought it is not reasonable for such a small task. But since it was part of the bootcamp process, and I was lacking knowledge on it, I have chosen it over monolithic architecture to push myself even further. Given that, it consists of three microservice mocks: Findex Inquiry Service, SMS Service, Loan Application Service. They are discovered by Eureka Service Registry and the incoming requests are routed by Spring Cloud Gateway to the corresponding services. Used RestTemplate to communicate with other services.

Loan Application Service

The main job of the service is to process the loan application request, send eligibility notices and log the applications to the database for later queries. It simply takes consumer info and returns a result message which contains eligibility status and credit limit. How it decides eligibility and credit limit? Well, if the credit score of the consumer which is acquired from Findex Inquiry Service is lower than 500, the consumer is not eligible. If it is higher, and the monthly income of the consumer is less then 5000 then the consumer is eligible for 10000 TRY, else if the monthly income is higher than 5000 the limit raises to 20000 TRY. If the score is higher then 1000, the credit limit is calculated as follows: limit = income*4. Credit score is acquired from Findex Inquiry Service. Always sends the result to the SMS Service to notify consumer on phone. Some unit tests are available under Test package for this service.

Endpoints

Endpoint	Method	Params	Description
/api/loan-applications	GET	id, filter	Get the application list by the given ID number. Support three types of filter : ASC, DESC, LAST. It is set to UNFILTERED by default.
/api/loan-applications	POST	none	Post a new application. Request a body which contains forename, surname, identificationNumber, monthlyIncome and the phone of the consumer.
/swagger-ui.html	GET	none	Swagger documentation page.

Findex Inquiry Service

This is a service which fictionally holds all the financial history of the consumer along with his/her credit score. In our situation, it just calculates the credit score according to a simple algorithm and returns it if queried. The credit score is calculated according to the last number of the identification number:

• 0 -> 2000
• 2 -> 550
• 4 -> 1000
• 6 -> 400
• 8 -> 900

Since it holds consumer related data, it has a Consumer database, on which basic CRUD operations are possible. Unit tests are available for this service under Test package.

Endpoints

Endpoint	Method	Params	Description
/api/creditscore-inquiry	POST	none	Get the credit score by the given CreditScoreInquiryRequest objec which contains forename, surname, identificationNumber of the consumer.
/api/consumers	POST	none	Create a new consumer, gets a request body which contains forename, surname, identificationNumber, monthlyIncome and the credit(it is optional, calculated automatically if not provided) of the consumer.
/api/consumers	GET	none	Get all the consumers.
/api/consumers	PUT	identificationNumber	Get the consumer with the given identification number and update it with the information provided in Consumer object.
/api/consumers	DELETE	identificaitonNumber	Delete the consumer with the given identification number.
/swagger-ui.html	GET	none	Swagger documentation page.

SMS Service

A simple service which takes a notification and simply prints it to the console. Just a mock, maybe could use Twilio or something? Sending real SMSs was not in the scope of the project anyways.

Endpoints

Endpoint	Method	Params	Description
/api/sms-dispatcher	POST	none	New SMS request which requires a SMSRequest object which contains phoneNumber, message and sentTime.
/swagger-ui.html	GET	none	Swagger documentation page.

Loan Application UI

It is made with Spring and Thymeleaf couple. Has a very simple design which consists of only seven pages, three of them for handling errors. Can be accessed on localhost:9191. !!!ATTENTION HERE!!! Be wary that form validations are purely HTML based. If it fails to validate you need to refresh the page to fill form again, or else it will keep giving the same validation error even if you enter a valid input. Unfortunately it is not possible to reset the form fields state without JS. Since this was not a frontend oriented project, I was lazy enough to not control validations via JS. :)

Past Applications Query Page

Filter can be set to sort the list. It will return the no logs found page if no logs found for the given consumer. Be wary that deleting the invalid input wont reset the forms state, you need to refresh the page.

New Credit Application Page

Consumer should already exist in the Findex Service consumer database or else it will return the consumer not found page. For it to acquire financial data, consumer needs to be exsistent right? Be wary that deleting the invalid input wont reset the forms state, you need to refresh the page.

Consumer List Page

Lists all the consumers available in the database. Some mock data are inserted during application initialization. From there you can also delete and update consumer information.

New Consumer Page

If the consumer is existent with the same identification number, it will return the consumer already existent error page. If credit score is not set, it will be calculated by the backend service. Be wary that deleting the invalid input wont reset the forms state, you need to refresh the page.

Consumer Update Page

You can update forename, surname and the credit score of the consumer. Be wary that deleting the invalid input wont reset the forms state, you need to refresh the page.

No Consumer Found Error Page

Is shown when the consumer is not found.

No Logs Found Error Page

Is shown when no logs found for the given consumer.

Consumer Already Exists Error Page

Is shown when the consumer already exists with the given identification number.

TODO

• Zipkin
• Spring Security
• Spring Cloud Hystrix
• Spring Cloud Config

Versions

All sub-modules 1.0 for initial stage.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.