most-active-cookie

Process a cookie log and return the most active cookie for a specific day

Tech

• Java 11, Spring Boot (framework), Maven (build tool)

Requirements

Given a cookie log file in the following format:

cookie,timestamp
AtY0laUfhglK3lC7,2018-12-09T14:19:00+00:00
SAZuXPGUrfbcn5UA,2018-12-09T10:13:00+00:00
5UAVanZf6UtGyKVS,2018-12-09T07:25:00+00:00
AtY0laUfhglK3lC7,2018-12-09T06:19:00+00:00
SAZuXPGUrfbcn5UA,2018-12-08T22:03:00+00:00
4sMM2LxV07bPJzwf,2018-12-08T21:30:00+00:00
fbcn5UAVanZf6UtG,2018-12-08T09:30:00+00:00
4sMM2LxV07bPJzwf,2018-12-07T23:30:00+00:00

• Write a command line program to process the log file and return the most active cookie for a specific day.
• Include a -f parameter for the filename to process and a -d parameter to specify the date.

e.g. we’d execute your program like this to obtain the most active cookie for 9th Dec 2018.

$ ./[command] -f cookie_log.csv -d 2018-12-09

And it would write to stdout:

AtY0laUfhglK3lC7

We define the most active cookie as one seen in the log the most times during a given day.

Assumptions

• If multiple cookies meet that criteria, please return all of them on separate lines.
• Only use additional libraries for testing, logging and cli-parsing.
• You can assume -d parameter takes date in UTC time zone.
• You have enough memory to store the contents of the whole file.
• Cookies in the log file are sorted by timestamp (most recent occurrence is the first line of the file).

Build

• Go to directory: cookie-filter
• Using Maven to build and package source code into a jar file:

mvn clean package

Build Successful

Run

• Still stand at the directory: cookie-filter
• Run the compiled jar file:

java -jar target\cookie-filter-version-SNAPSHOT.jar -f csv-file-path -d selected-date

• Example:

java -jar target\cookie-filter-0.0.1-SNAPSHOT.jar -f src\logs\cookie_log.csv -d 2018-12-09

Run Successful