piyushjha97/EventAggregatorApp

Json file parsing and aggregated daily event data for each user

Event Aggregator App

Event Aggregator App is a command-line utility written in Java that reads a list of user events from a JSON file, aggregates the events, and writes daily summary reports for every user back to another JSON file.

Usage

To use the Event Aggregator App, follow these steps:

1. Compile the Code:

    $javac -cp .:json-20210307.jar EventAggregatorApp.java
   

2. Run the App:

   2.1 for a fresh input file:

     $java -cp .:json-20210307.jar EventAggregatorApp -i input.json -o output.json
   

   2.2 if same input file is updated with new events:

   $java -cp .:json-20210307.jar EventAggregatorApp -i input.json -o output.json --update
   

   Replace input.json with the path to your input file and output.json with the desired output file path.

3. Options:

   • -i or --input: Path to the input JSON file.
   • -o or --output: Path to the output JSON file.
   • --update: Use this option to support real-time aggregation. It updates the corresponding daily summary report without reprocessing all previous events.

Example

If your input.json file contains:

[
  {"userId": 1, "eventType": "post", "timestamp": 1672444800},
  {"userId": 1, "eventType": "likeReceived", "timestamp": 1672444801},
  // ...
]

The output.json may look like this:

[
  {"userId": 1, "date": "2023-01-01", "post": 1, "likeReceived": 2},
  {"userId": 1, "date": "2023-01-02", "post": 1},
  // ...
]