Java-Matching-Engine REST API
A matching engine written in Java.
What is a matching engine?
A matching engine matches buy and sell orders in a market.
Matching Algorithm
The matching engine uses a price-time-priority algorithm. The matching priority is firstly price, then time. Market participants are rewarded for offering the best price and coming early.
Usage
It is recommended that every user of this service audits and verifies all underlying code for its validity and suitability. Mistakes and bugs happen.
To use this project, you will need to include the 'core' and 'restapi' packages as part of your Spring configuration scanning (as seen below).
@SpringBootApplication(scanBasePackages = {"net.laffyco.javamatchingengine.core", "net.laffyco.javamatchingengine.restapi"})
public class ExampleApp {
public static void main(final String[] args) {
SpringApplication.run(ExampleApp.class, args);
}
}
Usage Examples
Buying and Selling Example
Creating a maker order
User A creates a buy order of 2 items (e.g. 2 shares, 2 bitcoin, etc) with a price of 5 (e.g. £5, $5, etc)
Request
POST /order/
?side=BUY
&amount=2
&price=5
Response
{
"trades": [],
"id": "02923822-070b-448d-9240-f3623f90927a"
}
A unique ID is generated for the order (so that it can be modified/viewed). A list of trades is also returned. In this example the list of trades returned is empty as no trades have been made (due to the order book being empty).
Creating a taker order
User B creates a sell order of 2 items with a price of 5.
Request
POST /order/
?side=SELL
&amount=2
&price=5
Response
{
"trades": [
{
"takerOrderId": "12964731-2cd4-401b-ac8d-3853f58f75c0",
"makerOrderId": "02923822-070b-448d-9240-f3623f90927a",
"amount": 2,
"price": 5
}
],
"id": "12964731-2cd4-401b-ac8d-3853f58f75c0"
}
As the sell order matches the buy order created earlier we can see that a trade has taken place.
