GH-936 - Detect methods (meta-)annotated with @MessageMapping as module entry points.

We now consider all methods that are (meta-)annotated with Spring Messaging's @MessageMapping which is consistently used in a lot of broker annotations such as @(Rabbit|Kafka)Listener etc.

spring-modulith-core/src/main/java/org/springframework/modulith/core/Types.java

@@ -38,13 +38,24 @@ import com.tngtech.archunit.core.domain.JavaMethod;
 import com.tngtech.archunit.lang.ArchRule;
 
 /**
+ * Utility to deal with a variety of types.
+ *
  * @author Oliver Drotbohm
  */
-class Types {
+public class Types {
 
+	/**
+	 * Loads the class with the given name if present on the classpath.
+	 *
+	 * @param <T> the type to be loaded
+	 * @param name the fully-qualified name of the type to be loaded, must not be {@literal null} or empty.
+	 * @return can be {@literal null}.
+	 */
 	@Nullable
 	@SuppressWarnings("unchecked")
-	static <T> Class<T> loadIfPresent(String name) {
+	public static <T> Class<T> loadIfPresent(String name) {
+
+		Assert.hasText(name, "Name must not be null or empty!");
 
 		ClassLoader loader = Types.class.getClassLoader();