Bus Route Challenge

Introduction

This is my solution to Bus Route Challenge. For more information about Bus Route Challenge please refer to CHALLENGE.md file.

Approach

I decided to use Java 8 and Spring Boot (https://projects.spring.io/spring-boot/) for running Tomcat embedded server application to serve the REST Api.

Dependencies

The application packaging uses Maven. Additional dependencies included into the project are:

• Spring Boot Web Starter
• Spring Boot AOP Starter
• Lombok project (https://projectlombok.org/)
• JAMM Java Agent (https://github.com/jbellis/jamm) (licence: Apache Licence 2.0)

Design considerations

To accomplish the challenge requirements:

Your task is to implement a micro service which is able to answer whether there is a bus route providing a direct connection between two given stations.

I decided that there is no restriction in station position along a route. For example when we have routeId:1 and its stationIds:[1,2,3,4] it means that when requesting dep_sid=1 and arr_sid=4 returns true it would return true for dep_sid=4 and arr_sid=1 also.

The bus route data file will be a local file and your service will get the path to file as the first command line argument. Your service will get restarted if the file or its location changes.

I decided to pass the bus route data file as java argument to the program. When there is no argument passed - the application uses default data/example file.

To pass custom file to the application please use --file.path=example/path as the argument to the application i.e:

./service.sh dev_run --file.path=data/example

When you run ./service.sh dev_run without any file path, default file is being used.

WARNING: The docker command has not been tested ant it might not work.

Requirements

To run service.sh please make sure you have Maven and Java installed locally.

Error Codes

There are defined a few error codes in case of runtime exceptions:

INVALID_REQUEST_PARAMS - 1000
FILE_READING_ERROR - 1001
NO_DATA_LOADED_ON_THE_SERVER - 1002
FILE_HAS_NOT_ENOUGH_DATA - 1003
FILE_CONTAINS_INVALID_CHARACTERS - 1004
DEP_AND_ARR_IDS_ARE_THE_SAME - 1005

How to start

You need to build the application firstly, then you can run it.

To build Invoke ./service.sh dev_build in microservice directory.

To run Invoke ./service.sh dev_run --file.path=my/data/example/file

Where --file.path is an optional argument. When not set, the default example bus data provider is used from data/example subdirectory.

Default server port is 8088. You can override server port settings by adding command line argument --server.port i.e:

./service.sh dev_run --server.port=8082

Tests

There is coverage of unit tests for both services and rest controllers.

I included additional performance tests regarding log execution time of methods (Using Spring AOP) and memory consumption by objects (using JAMM open source library).