ormanli / order-book

Order Book implementation example

Order Book

An exchange allows the buyers and sellers of a product to discover each other and trade. Buyers and sellers (traders) submit orders to the exchange and the exchange applies simple rules to determine if a trade has occurred. The dominant kind of exchange is a central limit order book (CLOB) where orders are matched using ‘price time priority’.

When placing an order, traders specify if they wish to buy or sell, the limit price ie. worst possible price they will trade at, and the quantity (number of shares) they wish to trade. Trades only occur during the processing of a newly posted order, and happen immediately, which is known as ‘continuous trading’.

Requirements

• Java 19+
• Maven 3

Info

• Application starts and creates InputStreamReader from System.in and OutputStreamWriter from System.out.
• There two threads, first one is reading orders from InputStreamReader and pushing to a LinkedBlockingQueue.
• Second thread is consuming orders from LinkedBlockingQueue and adding to OrderBook. If trades happen after adding an order, it prints trades to OutputStreamWriter.
• After both of the threads are finished, the order book is printed to OutputStreamWriter.
• If an exception is thrown, application tries to process the orders to order book as much as possible.

How to create executable

mvn package

How to run

java -jar ./target/orderbook-1.0-SNAPSHOT.jar < ./src/test/resources/test2.txt