Java application designed to process and reconstruct customer financial transaction from raw data files into a consistent state. Application parses transaction logs, validates transaction integrity, and restores accurate customer balance sheets.
- Transaction Processing: Reads from structured CSV files to process transaction records efficiently.
- Compliance and Validation: Ensures all transactions comply with busineess rules, such as verifying user statuses, transaction types, and payment methods.
- Security Checks: Includes validation of card authenticity and transaction integrity based on BIN mappings and user-specific rules.
- Output Generation: Produces detailed reports on updated user balances and transaction outcomes, aiding in transparency and auditing.
- User Management: Handles user data, including balance checks and status management.
- Transaction Validation: Filters and validates transactions based on predefined rules and conditions.
- BIN Mapping Verification: Validates debit and credit card transactions against BIN ranges and types.
- Report Generation: Outputs the results in CSV format, detailing every processed transaction and updated user balances.
Run application with providing paths to INPUT files (Users, Transactions, BinMappings) and OUTPUT files (Balances, Events) in the following order: Users, Transactions, BinMappings, Balances, Events.
File location can be absolute path such as: YourDrive:/location/to/input/file.csv OR you can use provided test files and pass the path as src/main/resources/test-data/small/users.csv
Each input file is expected to have first row as header OR file must have data columns in following input formats:
| File | Header |
|---|---|
| Users | USER_ID,USERNAME,BALANCE,COUNTRY,FROZEN,DEPOSIT_MIN,WITHDRAW_MIN,WITHDRAW_MAX |
| Transactions | TRANSACTION_ID,USER_ID,TYPE,AMOUNT,METHOD,ACCOUNT_NUMBER |
| BinMappings | NAME,RANGE_FROM,RANGE_TO,TYPE,COUNTRY |
user_id- used in transactions to refer to the user.username- not used for any validations; a readable name may help with debugging.balance- user's current balance amount.country- two-letter country code, ISO 3166-1 alpha-2.frozen- 0 for an active user, 1 for frozen.deposit_min- amount, minimum allowed deposit, inclusive.deposit_max- amount, maximum allowed deposit, inclusive.withdraw_min- amount, minimum allowed withdrawal, inclusive.withdraw_max- amount, maximum allowed withdrawal, inclusive.
transaction_id- ID of the transaction.user_id- ID of the user.type- transaction type (allowed values are DEPOSIT or WITHDRAW).amount- amount.method- payment method (allowed values are CARD or TRANSFER).account_number- depends on method; card number for method=CARD, or IBAN for method=TRANSFER.
name- issuing bank name.range_from- the lowest possible card number (first 10 digits of card number) that would be identified within this card range, inclusive.range_to- the highest possible card number (first 10 digits of card number) that would be identified within this card range, inclusive.type- DC for debit and CC for credit cards.country- three-letter country code, ISO 3166-1 alpha-3.