Now, create the definitions for the StockPricer
and StockWatcher
services. First, define the listener service:
public class StockWatcher implements StockListener { public StockWatcher () { } public void stockPriceUpdated (StockEvent ev) { System.out.println ("Stock " + ev.getSymbol () + " is at price " + ev.getPrice ()); } }
Not much is needed here. Like all services, this requires a public constructor with no arguments. Aside from that, it implements StockListener
by printing the current stock price.