package u004;

/**

* Created by HuGuodong on 12/17/19.

*/

public interface MessageQueue {

void put();

}

interface MessageFormatter {

void format();

}

class KafkaMessageQueue implements MessageQueue {

@Override

public void put() {

}

}

class RocketMessageQueue implements MessageQueue {

@Override

public void put() {

}

}

class JsonMessageFormatter implements MessageFormatter {

@Override

public void format() {

}

}

class Demo {

MessageQueue queue;

Demo(MessageQueue queue) {

this.queue = queue;

}

void setNotification(MessageFormatter formatter) {

formatter.format();

}

public static void main(String[] args) {

}

}