event bus implementation that uses dynamic method invocation

core/src/main/groovy/com/muwire/core/EventBus.groovy

@@ -0,0 +1,30 @@
+package com.muwire.core
+
+import java.util.concurrent.CopyOnWriteArrayList
+
+import com.muwire.core.files.FileSharedEvent
+
+class EventBus {
+	
+	private Map handlers = new HashMap()
+
+	void publish(Event e) {
+		def currentHandlers
+		final def clazz = e.getClass()
+		synchronized(handlers) {
+			currentHandlers = handlers.getOrDefault(clazz, [])
+		}
+		currentHandlers.each {
+			it."on${clazz.getSimpleName()}"(e)
+		}
+	}
+	
+	synchronized void register(Class<? extends Event> eventType, def handler) {
+		def currentHandlers = handlers.get(eventType)
+		if (currentHandlers == null) {
+			currentHandlers = new CopyOnWriteArrayList()
+			handlers.put(eventType, currentHandlers)
+		}
+		currentHandlers.add handler
+	}
+}

core/src/test/groovy/com/muwire/core/EventBusTest.groovy

@@ -0,0 +1,26 @@
+package com.muwire.core
+
+import org.junit.Test
+
+class EventBusTest {
+
+	class FakeEvent extends Event {}
+	
+	class FakeEventHandler {
+		def onFakeEvent(FakeEvent e) {
+			assert e == fakeEvent
+		}
+	}
+	
+	FakeEvent fakeEvent = new FakeEvent()
+	
+	EventBus bus = new EventBus()
+	def handler = new FakeEventHandler()
+	
+	@Test
+	void testDynamicEvent() {
+		bus.register(FakeEvent.class, handler)
+		bus.publish(fakeEvent)
+	}
+
+}