Code to compute the total amount of money owed including compounded interest over time. It was written to calculate the amount owed based on the use of a credit line with variable interest rate over a decade.

Provide an accurate calculation of a debt that includes compounded interest, accumulated over an extended period of time from a set of operations that include both withdrawals that increase the debt and deposits that reduce it, with changing interest rates.

• An Operation can be either a TransactionOperation or a RateChangeOperation.
  • The TransactionOperation can be a withdrawal or a deposit that respectively increases or reduces the capital owed.
  • The RateChangeOperation defines the date and new rate when there is a change in the interest rate.
• The OperationFileReader reads a CSV file that contains the operations and creates an ArrayList<Operation> with the data contained in 4 columns:
  1. Date (format is 26 Jul 2023 or "dd MMM uuuu")
  2. Description (string description)
  3. Rate (variable annual interest rate)
  4. Amount (non-null for transactions and null for rate changes)
• The DebtCalculator takes the list of operations (constructor takes ArrayList<Operation>) and computes the totaCapital, totalInterest, and their sum, balanceOwed. The interest is compounded on a daily basis, which approximates very closely monthly compounding.

Two sample files are provided.

Spans 9 years, and shows examples of the three types of operations that include withdrawals, deposits, and interest rate changes.

Date,Description,AnnualRate,Amount
28 May 2014,ABM Cash Withdrawal,3.5,500.00
12 Sep 2014,EB BILL PYMT VISA,3.5,550.99
15 Sep 2014,Pre-Auth Pymt CEPEO,3.5,136.30
28 Jan 2015,Interest rate change,3.35,
03 Jun 2015,Purchase AutoPro,3.35,600.00 
16 Dec 2015,Purchase Provigo LeMarche,3.20,17.53 
07 Mar 2016,Purchase Cinema des Galleries,3.20,51.52
07 Mar 2016,ABM Cash Withdrawal CDS,3.20,504.00
07 Mar 2016,Service Charge,3.20,1.50
01 May 2016,Interest rate change,3.20,
23 Feb 2017,Purchase Uniprix,3.20,7.69
27 Feb 2017,Purchase Canadian Tire Gas Bar,3.20,31.01
27 Feb 2017,Purchase Petro Canada,3.20,52.52
25 Oct 2018,Interest rate change,4.45,
02 Nov 2018,Purchase Clinique Dentaire,4.45,398.00
09 Nov 2018,Purchase Costco Wholesale,4.45,210.04
30 Sep 2019,Purchase Marche LaFlame,4.45,4.09
08 Nov 2019,Purchase A&W Resto Vanier,4.45,32.15
10 Feb 2020,Purchase IGA Extra Grenier Fort,4.45,94.00
06 Mar 2020,Interest rate change,3.95,
02 Jun 2022,Interest rate change,4.20,
16 Jun 2022,Purchase Dental Clinic Prestige,4.20,740.00
14 Jul 2022,Interest rate change,5.20,
15 Sep 2022,Repayment e-Transfer,5.95,-1276.84
27 Oct 2022,Interest rate change,6.45,
10 Nov 2022,Repayment e-Transfer,6.45,-207
09 May 2023,Purchase Canadian Tire Gas Bar,7.20,65.04
08 Jun 2023,Interest rate change,7.45,

Spans exactly 10 years, and contains a single initial withdrawal of 10000 and a fixed interest rate of 3%. The purpose of this is to validate the compound interest calculation against an online calculator.

Date,Description,AnnualRate,Amount
01 Jan 2013,Initial withdrawal,3,10000
01 Jan 2023,Final operation,3,

1. Clone git clone [email protected]:gbelanger/debt-calculator.git
2. Compile cd debt-calculator ; javac *.java
3. Run java ComputeDebt sample-operations.csv