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Examples for optional lambda parameters and polymorphism with default methods
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| package example; | |
| import java.util.ArrayList; | |
| import java.util.List; | |
| import java.util.function.BiConsumer; | |
| import java.util.function.Consumer; | |
| /** | |
| * Created by beders on 7/7/15. | |
| */ | |
| public class BetterBus { | |
| public static class Event {} | |
| public static class Header {} | |
| public interface BaseHandler { | |
| default void dispatch(Event evt, Header header) {} | |
| } | |
| public interface EventHandler extends BaseHandler { | |
| void handle(Event evt); | |
| default void dispatch(Event evt, Header header) { | |
| handle(evt); // ignore header | |
| } | |
| } | |
| public interface EventAndHeaderHandler extends BaseHandler { | |
| void handle(Event evt, Header header); | |
| default void dispatch(Event evt, Header header) { | |
| handle(evt, header); | |
| } | |
| } | |
| List<BaseHandler> handlers = new ArrayList(); | |
| public void register(EventHandler handler) { | |
| handlers.add(handler); | |
| } | |
| public void register(EventAndHeaderHandler handler) { handlers.add(handler); } | |
| public void dispatch(Event event, Header header) { | |
| handlers.forEach(handler -> handler.dispatch(event, header)); | |
| } | |
| public static void main(String... args) { | |
| BetterBus bus = new BetterBus(); | |
| bus.register(event -> System.out.println("I gots an event")); | |
| bus.register((event,header) -> System.out.println("I gots an event w/ header")); | |
| bus.dispatch(new Event(), new Header()); | |
| } | |
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| package example; | |
| import java.util.ArrayList; | |
| import java.util.List; | |
| import java.util.function.BiConsumer; | |
| import java.util.function.Consumer; | |
| /** | |
| * Created by beders on 7/7/15. | |
| */ | |
| public class Bus { | |
| public static class Event {} | |
| public static class Header {} | |
| List<Object> handlers = new ArrayList(); | |
| public void register(Consumer<Event> handler) { | |
| handlers.add(handler); | |
| } | |
| public void register(BiConsumer<Event,Header> handler) { | |
| handlers.add(handler); | |
| } | |
| public void dispatch(Event event, Header header) { | |
| for (Object obj : handlers) { | |
| if (obj instanceof Consumer) { | |
| Consumer<Event> c = (Consumer<Event>) obj; | |
| c.accept(event); | |
| } else if (obj instanceof BiConsumer) { | |
| BiConsumer<Event, Header> b = (BiConsumer<Event, Header>) obj; | |
| b.accept(event, header); | |
| } | |
| } | |
| } | |
| public static void main(String... args) { | |
| Bus bus = new Bus(); | |
| bus.register(event -> System.out.println("I gots an event")); | |
| bus.register((event,header) -> System.out.println("I gots an event w/ header")); | |
| bus.dispatch(new Event(), new Header()); | |
| } | |
| } |
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