Allow event handlers with non-void return type

Also removed unnecessary files from the Event Bus Proc JAR and
configured GPG signing as well as deployment to Sonatype OSSRH.

README.md

@@ -5,13 +5,13 @@
 This library allows passing events between different objects without them having a direct reference to each other.
 Any object can serve as an event.
 
-Using an instance of the `EventBus` class, an instant of the event class can be dispatched.
+Using an instance of the `EventBus` class, an instance of the event class can be dispatched.
 This means that it will be forwarded to all listeners registered for it at the event bus.
 
 In addition, a singleton instance of the event bus is provided by the `EventBus#getInstance()` method.
 
 To listen to events, register event handling methods using the `Event` annotation.
-For this to work, the method must have a return type of `void` and declare a single parameter of the desired event type.
+For this to work, the method must declare a single parameter of the desired event type.
 Alternatively, a parameter-less event handler can be declared as shown [below](#parameter-less-event-handlers).
 
 ## A Simple Example
@@ -125,21 +125,14 @@ As event handlers are ordered by priority, it is not defined which of them will
 
 ## Installation
 
-Event Bus is currently hosted at [kske.dev](https://kske.dev/maven-repo/dev/kske/event-bus/).
+Event Bus is available in Maven Central.
-To include it inside your project, just add the Maven repository and the dependency to your `pom.xml`:
+To include it inside your project, just add the following dependency to your `pom.xml`:
 
 ```xml
-<repositories>
-	<repository>
-		<id>kske-repo</id>
-		<url>https://kske.dev/maven-repo</url>
-	</repository>
-</repositories>
-
 <dependencies>
     <dependency>
         <groupId>dev.kske</groupId>
-        <artifactId>event-bus</artifactId>
+        <artifactId>event-bus-core</artifactId>
         <version>1.0.0</version>
     </dependency>
 </dependencies>
@@ -175,7 +168,7 @@ When using Maven, it can be registered using the Maven Compiler Plugin:
         <annotationProcessorPaths>
             <annotationProcessorPath>
                 <groupId>dev.kske</groupId>
-                <artifactId>event-bus-ap</artifactId>
+                <artifactId>event-bus-proc</artifactId>
                 <version>1.0.0</version>
             </annotationProcessorPath>
         </annotationProcessorPaths>
@@ -183,4 +176,4 @@ When using Maven, it can be registered using the Maven Compiler Plugin:
 </plugin>
 ```
 
-Alternatively, a JAR file containing the processor is offered with each release for the use within IDEs and environments without Maven support.
+Alternatively, a JAR file containing the processor is offered with each release for the use within IDEs and environments without Maven support.

event-bus-core/src/main/java/dev/kske/eventbus/core/Event.java

@@ -6,17 +6,10 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
 import java.lang.annotation.*;
 
 /**
- * Indicates that a method is an event handler. To be successfully used as such, the method has to
+ * Indicates that a method is an event handler.
- * comply with the following specifications:
+ * <p>
- * <ul>
+ * To be successfully used as such, the method has to specify the event type by either declaring one
- * <li>Specifying an event type by either
+ * parameter of that type or setting the annotation value to the corresponding class.
- * <ul>
- * <li>Declaring one object parameter</li>
- * <li>Defining the class of the event using the annotation value</li>
- * </ul>
- * </li>
- * <li>Return type of {@code void}</li>
- * </ul>
  *
  * @author Kai S. K. Engelbart
  * @since 0.0.1

event-bus-core/src/main/java/dev/kske/eventbus/core/EventHandler.java

@@ -43,7 +43,7 @@ final class EventHandler implements Comparable<EventHandler> {
 		this.method		= method;
 		useParameter	= annotation.value() == USE_PARAMETER.class;
 
-		// Check for correct method signature and return type
+		// Check handler signature
 		if (method.getParameterCount() == 0 && useParameter)
 			throw new EventBusException(method + " does not define an event type!");
 
@@ -53,9 +53,6 @@ final class EventHandler implements Comparable<EventHandler> {
 		if (method.getParameterCount() > 1)
 			throw new EventBusException(method + " defines more than one parameter!");
 
-		if (!method.getReturnType().equals(void.class))
-			throw new EventBusException(method + " does not have a return type of void!");
-
 		// Determine handler properties
 		eventType	= useParameter ? method.getParameterTypes()[0] : annotation.value();
 		polymorphic	= method.isAnnotationPresent(Polymorphic.class);

event-bus-proc/pom.xml

@@ -50,6 +50,21 @@
 						</goals>
 						<configuration>
 							<minimizeJar>true</minimizeJar>
+							<filters>
+								<filter>
+									<artifact>dev.kske:event-bus-core</artifact>
+									<excludes>
+										<exclude>META-INF/MANIFEST.MF</exclude>
+									</excludes>
+								</filter>
+								<filter>
+									<artifact>*:*</artifact>
+									<excludes>
+										<exclude>module-info.class</exclude>
+										<exclude>META-INF/maven/**</exclude>
+									</excludes>
+								</filter>
+							</filters>
 						</configuration>
 					</execution>
 				</executions>

event-bus-proc/src/main/java/dev/kske/eventbus/proc/EventProcessor.java

@@ -60,8 +60,6 @@ public class EventProcessor extends AbstractProcessor {
 					"Either the method or the annotation must define the event type");
 			else if (eventHandler.getParameters().size() > 1)
 				error(eventHandler, "Method must not have more than one parameter");
-			else if (eventHandler.getReturnType().getKind() != TypeKind.VOID)
-				error(eventHandler, "Method must return void");
 			else
 				pass = true;
 

pom.xml

@@ -41,6 +41,7 @@
 	<scm>
 		<connection>scm:git:https://git.kske.dev/kske/event-bus.git</connection>
 		<developerConnection>scm:git:ssh://git@git.kske.dev:420/kske/event-bus.git</developerConnection>
+		<url>https://git.kske.dev/kske/event-bus</url>
 	</scm>
 
 	<properties>
@@ -50,6 +51,18 @@
 		<maven.compiler.target>11</maven.compiler.target>
 	</properties>
 
+	<!-- Configure deployment to OSSRH -->
+	<distributionManagement>
+		<snapshotRepository>
+			<id>ossrh</id>
+			<url>https://oss.sonatype.org/content/repositories/snapshots</url>
+		</snapshotRepository>
+		<repository>
+			<id>ossrh</id>
+			<url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
+		</repository>
+	</distributionManagement>
+
 	<build>
 
 		<!-- Disable test resource folder -->
@@ -64,7 +77,7 @@
 				<version>3.8.1</version>
 			</plugin>
 
-			<!-- Attach sources and Javadoc to JAR -->
+			<!-- Attach sources to JAR -->
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-source-plugin</artifactId>
@@ -78,6 +91,8 @@
 					</execution>
 				</executions>
 			</plugin>
+
+			<!-- Attach Javadoc to JAR -->
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-javadoc-plugin</artifactId>
@@ -92,6 +107,22 @@
 				</executions>
 			</plugin>
 
+			<!-- GPG sign JAR -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-gpg-plugin</artifactId>
+				<version>1.6</version>
+				<executions>
+					<execution>
+						<id>sign-artifacts</id>
+						<phase>verify</phase>
+						<goals>
+							<goal>sign</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+
 		</plugins>
 	</build>
 </project>