【Question】

The following transaction file is a CSV file that contains financial transactions, where each line is either a debit or a credit transaction on a specific account number.

 

00001500205568600,D,1520.15

00001500205568600,D,12500.00

00001500205568600,C,44.00

00001300220978215,C,59800.13

00001300220978215,C,80000.00

00001300220978215,C,15850.23

00001300220978215,D,85.60

00002200540006410,D,595550.03

00002200540006410,C,1200.00

00002200540006410,D,3250.00

00001300220978215,C,12.55

00009650025500020,C,290050.00

00009650025500020,D,96.00

 

Each line has the following format: <account number>,<D or C (D for debit and C for credit)>,<amount>. The file contains transactions for multiple account numbers, but more than one for each account number. I need to write a Java program that reads the transactions.txt file line by line and calculate the final balance of each account number. Assume that each account starts with 0 balance; and then the amount of each debit (D) transaction is subtracted from the balance and the amount of each credit (C) transaction is added to the balance. The program should print each account number with its final balance.

I have this code and I need help in making transaction and print them.

 

public class Test1 {

 

  public static void main(String[] args) {

 

      test1 obj = new test1();

    obj.run();

 

  }

 

  public void run() {

 

    String csvFile = "transactions.txt";

    BufferedReader br = null;

    String line = "";

    String cvsSplitBy = ",";

 

 

 

    try {

 

        br = new BufferedReader(new FileReader(csvFile));

        while ((line = br.readLine()) != null) {

 

                // use comma as separator

            String[] country = line.split(cvsSplitBy);

 

 

            System.out.println("Account Number " + country[0]

                                 + ", Account Balance=" + country[2] + "]");

 

        }

 

    } catch (FileNotFoundException e) {

        e.printStackTrace();

    } catch (IOException e) {

        e.printStackTrace();

    } finally {

        if (br != null) {

            try {

                br.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

 

    System.out.println("Done");

  }

 

}

 

【Answer】

When value of the 2^nd column is D, change the value in the 3^rd column into the negative, then group data and perform sums. Without further computing target, we can handle it in SPL (Structured Process Language). The code is simple and easy to understand:

	A
1	=file("d:\\source.csv").import@c()
2	=A1.run(if(#2=="D",#3=-#3))
3	=A2.groups(#1;sum(#3))

A1: Import source.csv.

 

A2: For D values in the 2^nd column, change the corresponding values in the 3^rd column to a negative.

 

A3: Group the 1^st column and the perform sum over the 3^rd column.

 

An SPL script is integration-friendly. See How to Call an SPL Script in Java to learn how to invoke an SPL script from a Java application.