当然,
下面是“观察者”模式的具体示例,该模式在记录器系统中使用类和接口来实现多态行为:
interface ILogger{ public void handleEvent (String event);}class FileLogger implements ILogger{ public void handleEvent (String event){ //write to file }}class ConsoleLogger implements ILogger{ public void handleEvent (String event){ System.out.println( event ); }}class Log { public void registerLogger (ILogger logger){ listeners.add(logger); } public void log (String event){ foreach (ILogger logger in listeners){ logger.handleEvent(event); //pass the log string to both ConsoleLogger and FileLogger! } } private ArrayList<ILogger> listeners;}然后,您可以按以下方式使用它:
public static void main(String [] args){ Log myLog(); FileLogger myFile(); ConsoleLogger myConsole(); myLog.registerLogger( myFile ); myLog.registerLogger( myConsole ); myLog.log("Hello World!!"); myLog.log("Second log event!");}希望这有助于您理解接口和多态性。



