jv-work-with-file

Implement method getStatistic(String fromFileName, String toFileName) which will return some data from the market after the working day.

This method has two parameters:

• String fromFileName - you should read data from this file
• String toFileName - you should write the result to this file

The input file has a .csv format. CSV is a simple file format used to store tabular data. This type of file is very popular for storing information. So we will start working with it. CSV stands for "comma-separated values". Its data fields are most often separated, or delimited by a comma.

For example, let's say you had a spreadsheet containing the following data:

operation type	amount
supply	30
buy	10
buy	13
supply	17
buy	10

The above data could be represented in a CSV-formatted file as follows:

supply,30
buy,10
buy,13
supply,17
buy,10

Your task is to read all data from an input CSV file, create a report, and write it to newFile (the name of this file is the second parameter in the method).

Example of the report:

supply,47
buy,33
result,14

Explanation:

• supply = 30 + 17 = 47
• buy = 10 + 13 + 10 = 33
• result = supply - buy = 47 - 33 = 14

Try to avoid these common mistakes, while solving task