REST API for Money Transfer Simulation

Table of contents

• General Info
• Technologies
• Implementation notes
• Copyright
• References

General Info

This API model an account service according to REST guidelines. It's able to create, access, find accounts and to transfer money between them.

For more info:

• Task Definition.pdf

Technologies

Project is created with:

• Java
• IntelliJ IDEA
• Spring Boot
• Spring Web MVC
• Spring Data JPA
• Spring HATEOAS
• H2
• JUnit 5
• Mockito
• Git

Implementation notes:

• Inputs will not be validated (for example with @Valid). The requirements do not ask for it, and I am short on time. It would be interesting to add it at some future point.
• 4 accounts functionalities have been implemented:
  • see all accounts at get(/accounts)
  • see an account at get(/accounts/{accountId})
  • create an account at post(/accounts)
  • edit an account at put(/accounts/{accountId})
• It has been decided that put also returns status 201
• The transfers will be modeled by the entity 'Transfer'
• transfers are perform at post(/transfers), passing as argument a 'Transfer' in json
• The @Transactional annotation has been used to ensure that transfers are perform transactionally
• The transaction propagation has been set to 'nested', considering it the most appropriate (source)
• when trying an illegal transaction or when trying to use an account that doesn't exist, the system returns an error message in json format
• there has been no need to unit test the persistence layer since no new queries have been added to the ones inherited from JpaRepository
• It would be interesting to take the currency into account when making transactions. For example, a service could be created to provide the exchange rate. In this exercise, for simplicity and due to not being explicitly indicated in the requirements, this issue has been ignored.

Copyright

• year: 2020
• project name: secondrest
• author: MISRRAIM SUÁREZ PÉREZ
• mail: misrraimsp@gmail.com
• last version: 13/09/2020

References

• Building REST services with Spring
• Unit Testing with Spring Boot
• Testing MVC Web Controllers with Spring Boot and @WebMvcTest
• Testing JPA Queries with Spring Boot and @DataJpaTest
• Integration Tests with Spring Boot and @SpringBootTest
• Mocking with (and without) Spring Boot
• Testing a HATEOAS service
• Global exception handling with @ControllerAdvice