Added groups

additionally added:
* serialVersionUID is now equal to 0L
* Renamed classes with a two-letter initialism according to convention

src/main/java/envoy/data/Contact.java

@@ -0,0 +1,58 @@
+package envoy.data;
+
+import java.io.Serializable;
+
+/**
+ * This class is the superclass for both {@link User} and {@link Group}.<br>
+ * It provides an id and a name for each user and group.<br>
+ * <br>
+ * Project: <strong>envoy-common</strong><br>
+ * File: <strong>Contact.java</strong><br>
+ * Created: <strong>24 Mar 2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy v0.1-beta
+ */
+public abstract class Contact implements Serializable {
+
+	private long	id;
+	private String	name;
+
+	private static final long serialVersionUID = 0L;
+
+	/**
+	 * Creates a new instance of a {@link Contact}.
+	 *
+	 * @param id   the id of this contact
+	 * @param name the name of this contact
+	 * @since Envoy Common v0.1-beta
+	 */
+	public Contact(long id, String name) {
+		this.id		= id;
+		this.name	= name;
+	}
+
+	/**
+	 * @return the ID of this {@link Contact}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public long getId() { return id; }
+
+	/**
+	 * @return the name of this {@link Contact}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public String getName() { return name; }
+
+	/**
+	 * @param newName the new name of this {@link Contact}
+	 * @since Envoy Common v0.1-beta
+	 */
+	public void setName(String newName) { name = newName; }
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String toString() { return String.format("Contact[id=%d,name=%s]", id, name); }
+}

src/main/java/envoy/data/Group.java

@@ -0,0 +1,68 @@
+package envoy.data;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Project: <strong>envoy-common</strong><br>
+ * File: <strong>Group.java</strong><br>
+ * Created: <strong>24 Mar 2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Common v0.1-beta
+ */
+public class Group extends Contact {
+
+	private static final long serialVersionUID = 0L;
+
+	// TODO add admins
+	private List<Long> memberIDs = new ArrayList<>();
+
+	/**
+	 * Creates a new instance of a {@link Group}.
+	 *
+	 * @param id   the id of this group
+	 * @param name the name of this group
+	 * @since Envoy Common v0.1-beta
+	 */
+	public Group(long id, String name) { super(id, name); }
+
+	/**
+	 * Creates a new instance of a {@link Group}.
+	 *
+	 * @param id        the id of this group
+	 * @param name      the name of this group
+	 * @param memberIDs the IDs of all members that should be preinitialized
+	 * @since Envoy Common v0.1-beta
+	 */
+	public Group(long id, String name, List<Long> memberIDs) {
+		super(id, name);
+		this.memberIDs = memberIDs;
+	}
+
+	/**
+	 * @return the IDs of all members of this group
+	 * @since Envoy Common v0.1-beta
+	 */
+	public List<Long> getMemberIDs() { return memberIDs; }
+
+	/**
+	 * @param memberIDs the member IDs to set
+	 * @since Envoy Common v0.1-beta
+	 */
+	public void setMemberIDs(List<Long> memberIDs) { this.memberIDs = memberIDs; }
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String toString() {
+		StringBuilder sb = new StringBuilder();
+		sb.append("Group[id=" + getId() + ",name=" + getName() + ",memberIDs=[");
+		memberIDs.forEach(id -> { sb.append(id); sb.append(", "); });
+		// deleting the final ", "
+		sb.delete(sb.length() - 2, sb.length());
+		sb.append("]]");
+		return sb.toString();
+	}
+}

src/main/java/envoy/data/IDGenerator.java

@@ -6,33 +6,33 @@ import java.io.Serializable;
  * Generates increasing IDs between two numbers.<br>
  * <br>
  * Project: <strong>envoy-common</strong><br>
- * File: <strong>IdGenerator.java</strong><br>
+ * File: <strong>IDGenerator.java</strong><br>
  * Created: <strong>31.12.2019</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Common v0.2-alpha
  */
-public class IdGenerator implements Serializable {
+public class IDGenerator implements Serializable {
 
 	private final long	end;
 	private long		current;
 
-	private static final long serialVersionUID = -1517378307055845147L;
+	private static final long serialVersionUID = 0L;
 
 	/**
-	 * Creates an instance of {@link IdGenerator}.
+	 * Creates an instance of {@link IDGenerator}.
 	 *
 	 * @param begin the first ID
 	 * @param size  the amount of IDs to provide
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public IdGenerator(long begin, long size) {
+	public IDGenerator(long begin, long size) {
 		current	= begin;
 		end		= begin + size;
 	}
 
 	@Override
-	public String toString() { return String.format("IdGenerator[current=%d,end=%d]", current, end); }
+	public String toString() { return String.format("IDGenerator[current=%d,end=%d]", current, end); }
 
 	/**
 	 * @return {@code true} if there are unused IDs remaining

src/main/java/envoy/data/MessageAttachment.java

@@ -19,7 +19,7 @@ import envoy.util.SerializationUtils;
  */
 public class MessageAttachment<T> implements Serializable {
 
-	private static final long	serialVersionUID	= 262683855157198013L;
+	private static final long	serialVersionUID	= 0L;
 	private T					value;
 
 	/**

src/main/java/envoy/data/MessageBuilder.java

@@ -33,11 +33,11 @@ public class MessageBuilder {
 	 *
 	 * @param senderId    the ID of the user who sends the {@link Message}
 	 * @param recipientId the ID of the user who receives the {@link Message}
-	 * @param idGenerator the ID generator used to generate a unique {@link Message}
+	 * @param iDGenerator the ID generator used to generate a unique {@link Message}
 	 *                    id
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public MessageBuilder(long senderId, long recipientId, IdGenerator idGenerator) { this(senderId, recipientId, idGenerator.next()); }
+	public MessageBuilder(long senderId, long recipientId, IDGenerator iDGenerator) { this(senderId, recipientId, iDGenerator.next()); }
 
 	/**
 	 * Creates an instance of {@link MessageBuilder} with all mandatory values
@@ -61,12 +61,12 @@ public class MessageBuilder {
 	 *
 	 * @param msg         the message to copy
 	 * @param recipientId the ID of the user who receives the {@link Message}
-	 * @param idGenerator the ID generator used to generate a unique {@link Message}
+	 * @param iDGenerator the ID generator used to generate a unique {@link Message}
 	 *                    id
 	 * @since Envoy v0.1-beta
 	 */
-	public MessageBuilder(Message msg, long recipientId, IdGenerator idGenerator) {
-		this(msg.getRecipientId(), recipientId, idGenerator.next());
+	public MessageBuilder(Message msg, long recipientId, IDGenerator iDGenerator) {
+		this(msg.getRecipientId(), recipientId, iDGenerator.next());
 		this.attachment		= msg.getAttachment();
 		this.creationDate	= new Date();
 		this.forwarded		= true;

src/main/java/envoy/data/User.java

@@ -1,7 +1,5 @@
 package envoy.data;
 
-import java.io.Serializable;
-
 /**
  * Represents a unique user with a unique, numeric ID, a name and a current
  * {@link UserStatus}.<br>
@@ -13,7 +11,7 @@ import java.io.Serializable;
  * @author Kai S. K. Engelbart
  * @since Envoy Common v0.2-alpha
  */
-public class User implements Serializable {
+public class User extends Contact {
 
 	/**
 	 * This enumeration defines all possible statuses a user can have.
@@ -44,24 +42,20 @@ public class User implements Serializable {
 		OFFLINE;
 	}
 
-	private final long		id;
-	private final String	name;
-
 	private UserStatus status;
 
-	private static final long serialVersionUID = 0L;
+	private static final long serialVersionUID = 1L;
 
 	/**
-	 * Initializes a {@link User}. The {@link UserStatus} is set to
-	 * {@link UserStatus#ONLINE}.
+	 * Initializes a {@link User}. <br>
+	 * The {@link UserStatus} is set to {@link UserStatus#ONLINE}.
 	 *
 	 * @param id   unique ID
 	 * @param name user name
 	 * @since Envoy Common v0.2-alpha
 	 */
 	public User(long id, String name) {
-		this.id		= id;
-		this.name	= name;
+		super(id, name);
 		status = UserStatus.ONLINE;
 	}
 
@@ -74,24 +68,12 @@ public class User implements Serializable {
 	 * @since Envoy Common v0.2-alpha
 	 */
 	public User(long id, String name, UserStatus status) {
-		this(id, name);
+		super(id, name);
 		this.status = status;
 	}
 
 	@Override
-	public String toString() { return String.format("User[id=%d,name=%s,status=%s]", id, name, status); }
-
-	/**
-	 * @return the ID of this {@link User}
-	 * @since Envoy Common v0.2-alpha
-	 */
-	public long getId() { return id; }
-
-	/**
-	 * @return the name of this {@link User}
-	 * @since Envoy Common v0.2-alpha
-	 */
-	public String getName() { return name; }
+	public String toString() { return String.format("User[id=%d,name=%s,status=%s]", getId(), getName(), status); }
 
 	/**
 	 * @return the current status of this user

src/main/java/envoy/event/ContactOperationEvent.java

@@ -39,7 +39,7 @@ public class ContactOperationEvent extends Event<User> {
 
 	private final Operation operationType;
 
-	private static final long serialVersionUID = -1166652868189511553L;
+	private static final long serialVersionUID = 0L;
 
 	/**
 	 * Initializes a {@link ContactOperationEvent}.

src/main/java/envoy/event/ContactSearchRequest.java

@@ -12,7 +12,7 @@ package envoy.event;
  */
 public class ContactSearchRequest extends Event<String> {
 
-	private static final long serialVersionUID = -7969312055630533627L;
+	private static final long serialVersionUID = 0L;
 
 	/**
 	 * Initializes a {@link ContactSearchRequest}.

src/main/java/envoy/event/ContactSearchResult.java

@@ -16,7 +16,7 @@ import envoy.data.User;
  */
 public class ContactSearchResult extends Event<List<User>> {
 
-	private static final long serialVersionUID = -8934154116102031561L;
+	private static final long serialVersionUID = 0L;
 
 	/**
 	 * Creates an instance of {@link ContactSearchResult}.

src/main/java/envoy/event/Event.java

@@ -15,7 +15,7 @@ public abstract class Event<T> implements Serializable {
 
 	protected final T value;
 
-	private static final long serialVersionUID = 4673659457380399167L;
+	private static final long serialVersionUID = 0L;
 
 	protected Event(T value) { this.value = value; }
 
@@ -39,7 +39,7 @@ public abstract class Event<T> implements Serializable {
 	 */
 	public static abstract class Valueless extends Event<Void> {
 
-		private static final long serialVersionUID = -9019362144094097997L;
+		private static final long serialVersionUID = 0L;
 
 		protected Valueless() { super(null); }
 

src/main/java/envoy/event/HandshakeRejectionEvent.java

@@ -44,7 +44,7 @@ public class HandshakeRejectionEvent extends Event<String> {
 	 */
 	public static final String UNKNOWN_REASON = "cause of failure is unknown";
 
-	private static final long serialVersionUID = -8723270093452609197L;
+	private static final long serialVersionUID = 0L;
 
 	/**
 	 * Creates an instance of {@link HandshakeRejectionEvent} with an empty reason.

src/main/java/envoy/event/IDGeneratorRequest.java

@@ -2,16 +2,16 @@ package envoy.event;
 
 /**
  * Signifies to the server that the client needs a new
- * {@link envoy.data.IdGenerator} instance.<br>
+ * {@link envoy.data.IDGenerator} instance.<br>
  * <br>
  * Project: <strong>envoy-common</strong><br>
- * File: <strong>IdGeneratorRequest.java</strong><br>
+ * File: <strong>IDGeneratorRequest.java</strong><br>
  * Created: <strong>28 Jan 2020</strong><br>
  *
  * @author Kai S. K. Engelbart
  * @since Envoy Common v0.3-alpha
  */
-public class IdGeneratorRequest extends Event.Valueless {
+public class IDGeneratorRequest extends Event.Valueless {
 
 	private static final long serialVersionUID = 1431107413883364583L;
 }

src/main/java/envoy/event/MessageStatusChangeEvent.java

@@ -17,7 +17,7 @@ public class MessageStatusChangeEvent extends Event<Message.MessageStatus> {
 	private final long	id;
 	private final Date	date;
 
-	private static final long serialVersionUID = 4566145392192761313L;
+	private static final long serialVersionUID = 0L;
 
 	/**
 	 * Initializes a {@link MessageStatusChangeEvent}.

src/main/java/envoy/event/UserStatusChangeEvent.java

@@ -15,7 +15,7 @@ public class UserStatusChangeEvent extends Event<UserStatus> {
 
 	private final long id;
 
-	private static final long serialVersionUID = 4566145392192761313L;
+	private static final long serialVersionUID = 0L;
 
 	/**
 	 * Initializes a {@link UserStatusChangeEvent}.