rkrux / moneytransfer

REST service that allows users to create bank accounts, transfer money between them, view them, and handle concurrent transfers requests safely.

Money Transfer Service

Business Features

• Create few sample bank accounts on startup
• Allow the user to add more bank accounts through a POST API
• Retrieve an account through a GET API
• Retrieve all accounts through a GET API
• Transfer funds between 2 accounts
• Handles synchronization in a multi-threaded scenario, ensuring data integrity

Build And Run

• Environment:

  OpenJDK 8
  

• Build:

  mvn clean install
  

• Run:

  java -jar target/moneytransfer-1.0-SNAPSHOT.jar
  

Testing

• Numerous extensive test cases cover this service
  • Unit Tests
  • Functional Tests
  • Integration Tests
  • Multi-Threaded Integration Tests, several parallel threads started in TransferAndGetIntegrationParallelTest.java

AddBankAccount POST API

• Endpoint: /bankAccount/add
• Returns HTTP 200 OK on successful request without body
• Sample Request Body:

  {
      "id": 10,
      "balance": 1
  }
  

• Errors:
  • HTTP 404 with "Incomplete transfer parameters" in Response body
  • HTTP 412 with "Illegal add account parameters" in Response body
  • HTTP 412 with "Account already present" in Response body

GetAccountById GET API

• Endpoint: /bankAccount/{id}
• Returns HTTP 200 OK on successful request with body
• Sample Response Body:

  {
      "id": 2,
      "balance": 50.00
  }
  

• Errors:
  • HTTP 404 with "Illegal get account parameters" in Response body
  • HTTP 412 with "Account not found" in Response body

GetAllAccounts GET API

• Endpoint: /bankAccount/all
• Returns HTTP 200 OK on successful request with body
• Sample Response Body:

  {
      "allBankAccounts": [
          {
              "id": 1,
              "balance": 100.00
          },
          {
              "id": 2,
              "balance": 50.00
          },
          {
              "id": 3,
              "balance": 20.52
          },
          {
              "id": 4,
              "balance": 30.61
          }
      ]
  }
  

TransferMoney POST API

• Endpoint: /transferMoney
• Returns HTTP 200 OK on successful request with body
• Sample Request Body:

  {
      "from": 1,
      "to": 2,
      "amount": 10
  }
  

• Sample Response Body:

  {
      "updatedAccounts": {
          "from": {
              "id": 1,
              "balance": 90.00
          },
          "to": {
              "id": 2,
              "balance": 60.00
          }
      }
  }
  

• Errors:
  • HTTP 404 with "Incomplete transfer parameters" in Response body
  • HTTP 412 with "Can't transfer funds to self" in Response body
  • HTTP 412 with "Only positive amount transfer allowed" in Response body
  • HTTP 412 with "Account not found" in Response body
  • HTTP 412 with "Account balance insufficient for this transfer" in Response body

Dependencies

• Jetty server 9
• Jersey 2
• Jackson 2
• Junit 4
• Vmlens Concurrent JUnit
• Jersey Test Framework Provider Jetty
• lombok