Added MessageBuilder, enhanced Javadoc

src/main/java/envoy/data/LoginCredentials.java

@@ -6,6 +6,8 @@ import java.security.NoSuchAlgorithmException;
 import java.util.Formatter;
 
 /**
+ * Contains a {@link User}'s login information.<br>
+ * <br>
  * Project: <strong>envoy-common</strong><br>
  * File: <strong>LoginCredentials.java</strong><br>
  * Created: <strong>29.12.2019</strong><br>
@@ -15,10 +17,11 @@ import java.util.Formatter;
  */
 public class LoginCredentials implements Serializable {
 
-	private static final long	serialVersionUID	= -7395245059059523314L;
 	private final String		name;
 	private final byte[]		passwordHash;
 
+	private static final long serialVersionUID = -7395245059059523314L;
+
 	/**
 	 * Creates an in stance of {@link LoginCredentials}.
 	 *
@@ -44,10 +47,7 @@ public class LoginCredentials implements Serializable {
 	 */
 	public byte[] getPasswordHash() { return passwordHash; }
 
-	private byte[] getSha256(byte[] input) throws NoSuchAlgorithmException {
-		MessageDigest md = MessageDigest.getInstance("SHA-256");
-		return md.digest(input);
-	}
+	private byte[] getSha256(byte[] input) throws NoSuchAlgorithmException { return MessageDigest.getInstance("SHA-256").digest(input); }
 
 	private byte[] toByteArray(char[] chars) {
 		byte[] bytes = new byte[chars.length * 2];
@@ -62,12 +62,9 @@ public class LoginCredentials implements Serializable {
 	public String toString() {
 		try (Formatter form = new Formatter()) {
 			form.format("LoginCredentials[name=%s,passwordHash=", name);
-			for (byte element : passwordHash) {
+			for (byte element : passwordHash)
 				form.format("%02x", element);
-			}
-			form.format("]");
-			String str = form.toString();
-			return str;
+			return form.format("]").toString();
 		}
 	}
 }

src/main/java/envoy/data/Message.java

@@ -3,7 +3,6 @@ package envoy.data;
 import java.io.Serializable;
 import java.text.SimpleDateFormat;
 import java.util.Date;
-import java.util.Optional;
 
 /**
  * Represents a unique message with a unique, numeric ID. Further metadata
@@ -18,10 +17,10 @@ import java.util.Optional;
  * @author Leon Hofmeister
  * @since Envoy Common v0.2-alpha
  */
-public abstract class Message implements Serializable {
+public class Message implements Serializable {
 
 	/**
-	 * This enum defines all possible statuses a {link Message} can have.
+	 * This enumeration defines all possible statuses a {link Message} can have.
 	 *
 	 * @since Envoy Common v0.2-alpha
 	 */
@@ -49,48 +48,41 @@ public abstract class Message implements Serializable {
 		READ
 	}
 
-	private static final long	serialVersionUID	= -4393477412979594435L;
-	private final long			id;
-
-	private final User sender, recipient;
-
-	private final Date date;
-
-	private final String text;
-
-	private final MessageAttachment<?> messageAttachment;
+	private final long					id;
+	private final User					sender, recipient;
+	private final Date					date;
+	private final String				text;
+	private final MessageAttachment<?>	attachment;
 
 	private MessageStatus status;
 
+	private static final long serialVersionUID = -4393477412979594435L;
+
 	/**
-	 * Initializes a {@link Message} from the client's perspective. The current date
-	 * is used as the message date and the status is set to
-	 * {@link MessageStatus#WAITING}.
+	 * Initializes a {@link Message} with values for all of its properties. The use
+	 * of this constructor is only intended for the {@link MessageBuilder} class, as
+	 * this class provides {@code null} checks and default values for all
+	 * properties.
 	 *
-	 * @param <T>        the type of the attachment
 	 * @param id         unique ID
 	 * @param sender     the user who sends the message
 	 * @param recipient  the user who receives the message
+	 * @param date       the creation date of the message
 	 * @param text       the text content of the message
 	 * @param attachment the attachment of the message, if present
+	 * @param status     the current {@link MessageStatus} of the message
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public <T> Message(long id, User sender, User recipient, String text, @SuppressWarnings("rawtypes") Optional<MessageAttachment> attachment) {
-		this.id					= id;
-		this.sender				= sender;
-		this.recipient			= recipient;
-		this.text				= text;
-		this.messageAttachment	= attachment.isEmpty() ? null : attachment.get();
-		this.date				= new Date();
-		this.status				= MessageStatus.WAITING;
+	Message(long id, User sender, User recipient, Date date, String text, MessageAttachment<?> attachment, MessageStatus status) {
+		this.id			= id;
+		this.sender		= sender;
+		this.recipient	= recipient;
+		this.date		= date;
+		this.text		= text;
+		this.attachment	= attachment;
+		this.status		= status;
 	}
 
-	/**
-	 * @return the date at which this message was created
-	 * @since Envoy Common v0.2-alpha
-	 */
-	public Date getDate() { return date; }
-
 	/**
 	 * @return the ID of this message
 	 * @since Envoy Common v0.2-alpha
@@ -98,11 +90,10 @@ public abstract class Message implements Serializable {
 	public long getId() { return id; }
 
 	/**
-	 * @param <T> the type of the message attachment
-	 * @return the messageAttachment
+	 * @return the sender of this message
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public <T> MessageAttachment<?> getMessageAttachment() { return messageAttachment; }
+	public User getSender() { return sender; }
 
 	/**
 	 * @return the recipient of this message
@@ -111,16 +102,10 @@ public abstract class Message implements Serializable {
 	public User getRecipient() { return recipient; }
 
 	/**
-	 * @return the sender of this message
+	 * @return the date at which this message was created
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public User getSender() { return sender; }
-
-	/**
-	 * @return the current status of this message
-	 * @since Envoy Common v0.2-alpha
-	 */
-	public MessageStatus getStatus() { return status; }
+	public Date getDate() { return date; }
 
 	/**
 	 * @return the text content of this message
@@ -128,6 +113,18 @@ public abstract class Message implements Serializable {
 	 */
 	public String getText() { return text; }
 
+	/**
+	 * @return the messageAttachment
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageAttachment<?> getAttachment() { return attachment; }
+
+	/**
+	 * @return the current status of this message
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageStatus getStatus() { return status; }
+
 	/**
 	 * Changes the current {@link MessageStatus} to the next logical status.<br>
 	 * <br>
@@ -148,7 +145,7 @@ public abstract class Message implements Serializable {
 
 	@Override
 	public String toString() {
-		return String.format("TextMessage[id=%d,sender=%s,recipient=%s,date=%s,status=%s,content=%s]",
+		return String.format("TextMessage[id=%d,sender=%s,recipient=%s,date=%s,status=%s,text=%s]",
 				id,
 				sender,
 				recipient,

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

@@ -2,10 +2,8 @@ package envoy.data;
 
 import java.io.Serializable;
 
-import javax.swing.Scrollable;
-
 /**
- * This Interface should be used for any type supposed to be a {@link Message}
+ * This interface should be used for any type supposed to be a {@link Message}
  * attachment (i.e. images or sound).<br>
  * <br>
  * Project: <strong>envoy-common</strong><br>
@@ -16,7 +14,7 @@ import javax.swing.Scrollable;
  * @param <T> the type of this message attachment
  * @since Envoy Common v0.2-alpha
  */
-public interface MessageAttachment<T> extends Serializable, Scrollable {
+public interface MessageAttachment<T> extends Serializable {
 
 	/**
 	 * @return the type implementing this interface

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

@@ -0,0 +1,125 @@
+package envoy.data;
+
+import java.util.Date;
+
+import envoy.data.Message.MessageStatus;
+
+/**
+ * Provides a method of constructing the {@link Message} class.<br>
+ * <br>
+ * Project: <strong>envoy-common</strong><br>
+ * File: <strong>MessageBuilder.java</strong><br>
+ * Created: <strong>31.12.2019</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy Common v0.2-alpha
+ */
+public class MessageBuilder {
+
+	// Mandatory properties without default values
+	private final User sender, recipient;
+
+	// Properties with default values
+	private long					id;
+	private Date					date;
+	private String					text;
+	private MessageAttachment<?>	attachment;
+	private Message.MessageStatus	status;
+
+	/**
+	 * Creates an instance of {@link MessageBuilder} with all mandatory values
+	 * without defaults for the {@link Message} class.
+	 *
+	 * @param sender    the user who sends the {@link Message}
+	 * @param recipient the user who received the {@link Message}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageBuilder(User sender, User recipient) {
+		if (sender == null) throw new NullPointerException("Message sender is null");
+		if (recipient == null) throw new NullPointerException("Message recipient is null");
+		this.sender		= sender;
+		this.recipient	= recipient;
+	}
+
+	/**
+	 * Creates an instance of {@link Message} with the previously supplied values.
+	 * If a mandatory value is not set, a default value will be used instead:<br>
+	 * <br>
+	 * <table border="1">
+	 * <tr>
+	 * <td>{@code date}</td>
+	 * <td>{@code new Date()}</td>
+	 * <tr>
+	 * <tr>
+	 * <td>{@code text}</td>
+	 * <td>{@code ""}</td>
+	 * <tr>
+	 * <tr>
+	 * <td>{@code status}</td>
+	 * <td>{@code MessageStatus.WAITING}</td>
+	 * <tr>
+	 * </table>
+	 * 
+	 * @return a new instance of {@link Message}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public Message build() {
+		// Supplement default values
+		if (date == null) date = new Date();
+		if (text == null) text = "";
+		if (status == null) status = MessageStatus.WAITING;
+
+		return new Message(id, sender, recipient, date, text, attachment, status);
+	}
+
+	/**
+	 * @param id the unique ID of the {@link Message} to create
+	 * @return this {@link MessageBuilder}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageBuilder setId(long id) {
+		this.id = id;
+		return this;
+	}
+
+	/**
+	 * @param date the creation date of the {@link Message} to create
+	 * @return this {@link MessageBuilder}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageBuilder setDate(Date date) {
+		this.date = date;
+		return this;
+	}
+
+	/**
+	 * @param text the text of the {@link Message} to create
+	 * @return this {@link MessageBuilder}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageBuilder setText(String text) {
+		this.text = text;
+		return this;
+	}
+
+	/**
+	 * @param attachment the {@link MessageAttachment} of the {@link Message} to
+	 *                   create
+	 * @return this {@link MessageBuilder}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageBuilder setAttachment(MessageAttachment<?> attachment) {
+		this.attachment = attachment;
+		return this;
+	}
+
+	/**
+	 * @param status the {@link MessageStatus} of the {@link Message} to create
+	 * @return this {@link MessageBuilder}
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public MessageBuilder setStatus(Message.MessageStatus status) {
+		this.status = status;
+		return this;
+	}
+}

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

@@ -16,7 +16,7 @@ import java.io.Serializable;
 public class User implements Serializable {
 
 	/**
-	 * This enum defines all possible statuses a user can have.
+	 * This enumeration defines all possible statuses a user can have.
 	 *
 	 * @since Envoy Common v0.2-alpha
 	 */
@@ -44,14 +44,13 @@ public class User implements Serializable {
 		OFFLINE;
 	}
 
-	private static final long serialVersionUID = 3530947374856708236L;
-
 	private final long id;
-
 	private final String name;
 
 	private UserStatus status;
 
+	private static final long serialVersionUID = 3530947374856708236L;
+
 	/**
 	 * Initializes a {@link User}. The {@link UserStatus} is set to
 	 * {@link UserStatus#OFFLINE}.

src/main/java/envoy/event/MessageEvent.java

@@ -11,6 +11,9 @@ import envoy.data.Message;
  */
 public class MessageEvent implements Event<Message> {
 
+	/**
+	 * the {@link Message} attached to this {@link MessageEvent}.
+	 */
 	protected final Message message;
 
 	/**