Java program for file processing.

Given a list of [FileName, FileSize, [Collection]] - Collection is optional, i.e., a collection can have 1 or more files. Same file can be a part of more than 1 collection.

How would you design a system

To calculate total size of files processed.

To calculate Top K collections based on size.

Example:

file1.txt(size: 100)

file2.txt(size: 200) in collection "collection1"

file3.txt(size: 200) in collection "collection1"

file4.txt(size: 300) in collection "collection2"

file5.txt(size: 100)

Output:

Total size of files processed: 900

Top 2 collections:

collection1 : 400

collection2 : 300

Follow up questions:

1] Concurrent calls handling - Synchronization

2] Tradeoff between speed and storage of file information

3] IF you used list not Set ,then why set etc.