refaturing message system, step 3: making use of queue

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

core/src/main/java/de/srsoftware/umbrella/core/api/PostBox.java

@@ -4,5 +4,5 @@ package de.srsoftware.umbrella.core.api;
 import de.srsoftware.umbrella.core.model.Envelope;
 
 public interface PostBox {
-	public void send(Envelope envelope);
+	public void send(Envelope<?> envelope);
 }

core/src/main/java/de/srsoftware/umbrella/core/model/Envelope.java

@@ -17,16 +17,16 @@ import java.util.stream.Collectors;
 import org.json.JSONArray;
 import org.json.JSONObject;
 
-public class Envelope<T> {
-	private final Message<T> message;
+public class Envelope<T extends Message<?>> {
+	private final T message;
 	private final Set<User> receivers;
 	private final LocalDateTime time;
 
-	public Envelope(Message<T> message, User receiver){
+	public Envelope(T message, User receiver){
 		this(message,new HashSet<>(Set.of(receiver)));
 	}
 
-	public Envelope(Message<T> message, HashSet<User> receivers) {
+	public Envelope(T message, HashSet<User> receivers) {
 		this.message = message;
 		this.receivers = receivers;
 		time = LocalDateTime.now();
@@ -38,7 +38,7 @@ public class Envelope<T> {
 	 * @return
 	 * @throws UmbrellaException
 	 */
-	public static Envelope from(JSONObject json) throws UmbrellaException {
+	public static Envelope<TranslatedMessage> from(JSONObject json) throws UmbrellaException {
 		if (!json.has(RECEIVERS)) throw missingField(RECEIVERS);
 		var message = TranslatedMessage.from(json);
 		var obj = json.get(RECEIVERS);
@@ -49,12 +49,12 @@ public class Envelope<T> {
 			if (!(o instanceof JSONObject receiverData)) throw invalidField("entries of "+ RECEIVERS, t(JSONOBJECT));
 			receivers.add(User.of(receiverData));
 		}
-		return new Envelope(message,receivers);
+		return new Envelope<>(message,receivers);
 	}
 
 	@Override
 	public final boolean equals(Object o) {
-		if (!(o instanceof Envelope envelope)) return false;
+		if (!(o instanceof Envelope<?> envelope)) return false;
 		return message.equals(envelope.message) && time.equals(envelope.time);
 	}
 
@@ -67,7 +67,7 @@ public class Envelope<T> {
 		return receivers.contains(receiver);
 	}
 
-	public Message<T> message(){
+	public T message(){
 		return message;
 	}