The app consists of two parts: backend containing different reactive and non-reactive service implementations and mobile frontend for using the exposed rest services.

Backend is a Spring Boot application and can be started by running:

apm287-stock-backend$ ./gradle bootRun

The properties of the application is defined in the application.properties and there it's possible to:

• select type of service implementation (akka, java-sync, java-concurrent, etc)
• define properties of the ApprovalService that can serve as bottle-neck in the app

Available REST points are:

• http://localhost:8080/balance
• http://localhost:8080/stocks
• http://localhost:8080/buy?c=code&s=size
• http://localhost:8080/sell?c=code&s=size

When started application can be remotely debugged on port 9080.

For mobile / web front end to start you need to install NodeJS on your machine. Then use npm command to install the following:

npm install ionic cordova -g
npm install chart.js --save

Then the app can be served with:

apm287-stock-mobile$ ionic serve

and accessible on http://localhost:8100.

If you wish to implement a new stock service and try out new library please implement the IStockService interface. Interface methods return Java Object as result so you can return anything you wish if this is allowed as result by Spring Rest. Thus, you can return DTO objects, but also Future, CompletableFuture, etc.

The general requirements are:

• There are at least 5 stocks
• Stocks are updated every second (by an external thread, executor, message)
• Stocks can be bought and sold with the current price
• Starting balance is 10,000 and can be used for buying stocks
• When buying more than 5 stocks, ApprovalService must be called to authorize the transaction
• You can only buy stocks if enough balance to pay them
• You can only sell stocks if you own them

To better understand the general requirements check de.novatec.apm287.java.sync.StockManager which implements requirements in plan Java using synchronized methods.

Once new service is implemented, please add the option to use in the de.novatec.apm287.Apm287Application and change the application.properties to use the new implementation.

Gatling load test is located under gatling/ folder. It can be used to generate considerable load on the backend. Please note that used service implementation and ApprovalService settings heavily affect the load test results.