Provide hashCode, equals and toString implementations for Entity

src/main/java/de/thm/arsnova/entities/Answer.java

@@ -4,73 +4,21 @@ import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonView;
 import de.thm.arsnova.entities.serialization.View;
 
-import java.util.Date;
 import java.util.Map;
+import java.util.Objects;
 
 @JsonTypeInfo(
 		use = JsonTypeInfo.Id.MINIMAL_CLASS,
 		include = JsonTypeInfo.As.PROPERTY,
 		property = "type"
 )
-public abstract class Answer implements Entity {
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
+public abstract class Answer extends Entity {
 	private String contentId;
 	private String roomId;
 	private String creatorId;
 	private int round;
 	private Map<String, Map<String, ?>> extensions;
 
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getId() {
-		return id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setId(final String id) {
-		this.id = id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getRevision() {
-		return rev;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setRevision(final String rev) {
-		this.rev = rev;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public String getContentId() {
 		return contentId;
@@ -119,4 +67,26 @@ public abstract class Answer implements Entity {
 	public void setExtensions(Map<String, Map<String, ?>> extensions) {
 		this.extensions = extensions;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * The following fields of <tt>Answer</tt> are excluded from equality checks:
+	 * {@link #extensions}.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final Answer answer = (Answer) o;
+
+		return round == answer.round &&
+				Objects.equals(contentId, answer.contentId) &&
+				Objects.equals(roomId, answer.roomId) &&
+				Objects.equals(creatorId, answer.creatorId);
+	}
 }

src/main/java/de/thm/arsnova/entities/Attachment.java

@@ -3,13 +3,9 @@ package de.thm.arsnova.entities;
 import com.fasterxml.jackson.annotation.JsonView;
 import de.thm.arsnova.entities.serialization.View;
 
-import java.util.Date;
+import java.util.Objects;
 
-public class Attachment implements Entity {
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
+public class Attachment extends Entity {
 	private String mediaType;
 	private long size;
 	private String originalSourceUrl;
@@ -39,30 +35,6 @@ public class Attachment implements Entity {
 		this.rev = rev;
 	}
 
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public String getMediaType() {
 		return mediaType;
@@ -102,4 +74,25 @@ public class Attachment implements Entity {
 	public void setStorageLocation(String storageLocation) {
 		this.storageLocation = storageLocation;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * All fields of <tt>Attachment</tt> are included in equality checks.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final Attachment that = (Attachment) o;
+
+		return size == that.size &&
+				Objects.equals(mediaType, that.mediaType) &&
+				Objects.equals(originalSourceUrl, that.originalSourceUrl) &&
+				Objects.equals(storageLocation, that.storageLocation);
+	}
 }

src/main/java/de/thm/arsnova/entities/Comment.java

@@ -5,12 +5,9 @@ import de.thm.arsnova.entities.serialization.View;
 
 import java.util.Date;
 import java.util.Map;
+import java.util.Objects;
 
-public class Comment implements Entity {
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
+public class Comment extends Entity {
 	private String roomId;
 	private String creatorId;
 	private String subject;
@@ -19,54 +16,6 @@ public class Comment implements Entity {
 	private boolean read;
 	private Map<String, Map<String, ?>> extensions;
 
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getId() {
-		return id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setId(final String id) {
-		this.id = id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getRevision() {
-		return rev;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setRevision(final String rev) {
-		this.rev = rev;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public String getRoomId() {
 		return roomId;
@@ -136,4 +85,29 @@ public class Comment implements Entity {
 	public void setExtensions(Map<String, Map<String, ?>> extensions) {
 		this.extensions = extensions;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * The following fields of <tt>LogEntry</tt> are excluded from equality checks:
+	 * {@link #extensions}.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final Comment comment = (Comment) o;
+
+		return read == comment.read &&
+				Objects.equals(roomId, comment.roomId) &&
+				Objects.equals(creatorId, comment.creatorId) &&
+				Objects.equals(subject, comment.subject) &&
+				Objects.equals(body, comment.body) &&
+				Objects.equals(timestamp, comment.timestamp) &&
+				Objects.equals(extensions, comment.extensions);
+	}
 }

src/main/java/de/thm/arsnova/entities/Content.java

@@ -6,13 +6,14 @@ import de.thm.arsnova.entities.serialization.View;
 
 import java.util.Date;
 import java.util.Map;
+import java.util.Objects;
 
 @JsonTypeInfo(
 		use = JsonTypeInfo.Id.MINIMAL_CLASS,
 		include = JsonTypeInfo.As.PROPERTY,
 		property = "type"
 )
-public class Content implements Entity {
+public class Content extends Entity {
 	public enum Format {
 		CHOICE,
 		BINARY,
@@ -91,10 +92,6 @@ public class Content implements Entity {
 		}
 	}
 
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
 	private String roomId;
 	private String subject;
 	private String body;
@@ -105,54 +102,6 @@ public class Content implements Entity {
 	private Map<String, Map<String, ?>> extensions;
 	private Map<String, String> attachments;
 
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getId() {
-		return id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setId(final String id) {
-		this.id = id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getRevision() {
-		return rev;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setRevision(final String rev) {
-		this.rev = rev;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public String getRoomId() {
 		return roomId;
@@ -246,4 +195,28 @@ public class Content implements Entity {
 	public void setAttachments(final Map<String, String> attachments) {
 		this.attachments = attachments;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * The following fields of <tt>LogEntry</tt> are excluded from equality checks:
+	 * {@link #state}, {@link #extensions}, {@link #attachments}.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final Content content = (Content) o;
+
+		return Objects.equals(roomId, content.roomId) &&
+				Objects.equals(subject, content.subject) &&
+				Objects.equals(body, content.body) &&
+				format == content.format &&
+				Objects.equals(group, content.group) &&
+				Objects.equals(timestamp, content.timestamp);
+	}
 }

src/main/java/de/thm/arsnova/entities/Entity.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2018 The ARSnova Team
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.entities;
 
 import com.fasterxml.jackson.annotation.JsonView;
 import de.thm.arsnova.entities.serialization.View;
+import org.springframework.core.style.ToStringCreator;
 
 import java.util.Date;
+import java.util.Objects;
 
-public interface Entity {
-	String getId();
-	void setId(String id);
+/**
+ * Used as base for classes that represent persistent data with an unique ID.
+ *
+ * @author Daniel Gerhardt
+ */
+public abstract class Entity {
+	protected String id;
+	protected String rev;
+	protected Date creationTimestamp;
+	protected Date updateTimestamp;
 
-	String getRevision();
-	void setRevision(String rev);
+	@JsonView({View.Persistence.class, View.Public.class})
+	public String getId() {
+		return id;
+	}
+
+	@JsonView({View.Persistence.class, View.Public.class})
+	public void setId(final String id) {
+		this.id = id;
+	}
+
+	@JsonView({View.Persistence.class, View.Public.class})
+	public String getRevision() {
+		return rev;
+	}
+
+	@JsonView({View.Persistence.class, View.Public.class})
+	public void setRevision(final String rev) {
+		this.rev = rev;
+	}
 
-	Date getCreationTimestamp();
-	void setCreationTimestamp(Date creationTimestamp);
+	@JsonView(View.Persistence.class)
+	public Date getCreationTimestamp() {
+		return creationTimestamp;
+	}
+
+	@JsonView(View.Persistence.class)
+	public void setCreationTimestamp(final Date creationTimestamp) {
+		this.creationTimestamp = creationTimestamp;
+	}
+
+	@JsonView(View.Persistence.class)
+	public Date getUpdateTimestamp() {
+		return updateTimestamp;
+	}
 
-	Date getUpdateTimestamp();
-	void setUpdateTimestamp(Date updateTimestamp);
+	@JsonView(View.Persistence.class)
+	public void setUpdateTimestamp(final Date updateTimestamp) {
+		this.updateTimestamp = updateTimestamp;
+	}
 
 	@JsonView(View.Persistence.class)
-	default Class<? extends Entity> getType() {
+	public Class<? extends Entity> getType() {
 		return getClass();
 	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(id, rev, creationTimestamp, updateTimestamp);
+	}
+
+	/**
+	 * Use this helper method when overriding {@link #hashCode()}.
+	 *
+	 * @param init The result of <tt>super.hashCode()</tt>
+	 * @param additionalFields Fields introduced by the subclass which should be included in the hash code generation
+	 *
+	 * @see java.util.Arrays#hashCode(Object[])
+	 */
+	protected int hashCode(final int init, final Object... additionalFields) {
+		int result = init;
+		if (additionalFields == null) {
+			return result;
+		}
+		for (Object element : additionalFields) {
+			result = 31 * result + (element == null ? 0 : element.hashCode());
+		}
+
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		final Entity entity = (Entity) o;
+
+		return Objects.equals(id, entity.id) &&
+				Objects.equals(rev, entity.rev) &&
+				Objects.equals(creationTimestamp, entity.creationTimestamp) &&
+				Objects.equals(updateTimestamp, entity.updateTimestamp);
+	}
+
+	@Override
+	public String toString() {
+		return buildToString().toString();
+	}
+
+	/**
+	 * Use this helper method to adjust the output of {@link #toString()}.
+	 * Override this method instead of <tt>toString()</tt> and call <tt>super.buildToString()</tt>.
+	 * Additional fields can be added to the String by calling
+	 * {@link org.springframework.core.style.ToStringCreator#append} on the <tt>ToStringCreator</tt>.
+	 */
+	protected ToStringCreator buildToString() {
+		ToStringCreator toStringCreator = new ToStringCreator(this);
+		toStringCreator
+				.append("id", id)
+				.append("revision", rev)
+				.append("creationTimestamp", creationTimestamp)
+				.append("updateTimestamp", updateTimestamp);
+
+		return toStringCreator;
+	}
 }

src/main/java/de/thm/arsnova/entities/LogEntry.java

@@ -6,8 +6,9 @@ import de.thm.arsnova.entities.serialization.View;
 
 import java.util.Date;
 import java.util.Map;
+import java.util.Objects;
 
-public class LogEntry implements Entity {
+public class LogEntry extends Entity {
 	public enum LogLevel {
 		TRACE,
 		DEBUG,
@@ -109,4 +110,28 @@ public class LogEntry implements Entity {
 	public void setPayload(final Map<String, Object> payload) {
 		this.payload = payload;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * The following fields of <tt>LogEntry</tt> are excluded from equality checks:
+	 * {@link #payload}.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final LogEntry logEntry = (LogEntry) o;
+
+		return level == logEntry.level &&
+				Objects.equals(id, logEntry.id) &&
+				Objects.equals(rev, logEntry.rev) &&
+				Objects.equals(creationTimestamp, logEntry.creationTimestamp) &&
+				Objects.equals(updateTimestamp, logEntry.updateTimestamp) &&
+				Objects.equals(event, logEntry.event);
+	}
 }

src/main/java/de/thm/arsnova/entities/MigrationState.java

@@ -6,8 +6,9 @@ import de.thm.arsnova.entities.serialization.View;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
+import java.util.Objects;
 
-public class MigrationState implements Entity {
+public class MigrationState extends Entity {
 	public static class Migration {
 		private String id;
 		private Date start;
@@ -38,12 +39,13 @@ public class MigrationState implements Entity {
 	}
 
 	public static final String ID = "MigrationState";
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
 	private Migration active;
 	private List<String> completed = new ArrayList<>();
 
+	{
+		id = ID;
+	}
+
 	@Override
 	@JsonView(View.Persistence.class)
 	public String getId() {
@@ -70,30 +72,6 @@ public class MigrationState implements Entity {
 		this.rev = rev;
 	}
 
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public Migration getActive() {
 		return active;
@@ -117,4 +95,23 @@ public class MigrationState implements Entity {
 	public void setCompleted(final List<String> completed) {
 		this.completed = completed;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * All fields of <tt>MigrationState</tt> are included in equality checks.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final MigrationState that = (MigrationState) o;
+
+		return Objects.equals(active, that.active) &&
+				Objects.equals(completed, that.completed);
+	}
 }

src/main/java/de/thm/arsnova/entities/Motd.java

@@ -4,8 +4,9 @@ import com.fasterxml.jackson.annotation.JsonView;
 import de.thm.arsnova.entities.serialization.View;
 
 import java.util.Date;
+import java.util.Objects;
 
-public class Motd implements Entity {
+public class Motd extends Entity {
 	public enum Audience {
 		ALL,
 		AUTHENTICATED,
@@ -14,10 +15,6 @@ public class Motd implements Entity {
 		ROOM
 	}
 
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
 	private String roomId;
 	private Date startDate;
 	private Date endDate;
@@ -25,38 +22,6 @@ public class Motd implements Entity {
 	private String body;
 	private Audience audience;
 
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getId() {
-		return id;
-	}
-
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setId(final String id) {
-		this.id = id;
-	}
-
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setRevision(final String rev) {
-		this.rev = rev;
-	}
-
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getRevision() {
-		return rev;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
 	@Override
 	@JsonView(View.Persistence.class)
 	public Date getUpdateTimestamp() {
@@ -128,4 +93,27 @@ public class Motd implements Entity {
 	public void setAudience(final Audience audience) {
 		this.audience = audience;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * All fields of <tt>Motd</tt> are included in equality checks.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final Motd motd = (Motd) o;
+
+		return Objects.equals(roomId, motd.roomId) &&
+				Objects.equals(startDate, motd.startDate) &&
+				Objects.equals(endDate, motd.endDate) &&
+				Objects.equals(title, motd.title) &&
+				Objects.equals(body, motd.body) &&
+				audience == motd.audience;
+	}
 }

src/main/java/de/thm/arsnova/entities/Room.java

@@ -3,11 +3,11 @@ package de.thm.arsnova.entities;
 import com.fasterxml.jackson.annotation.JsonView;
 import de.thm.arsnova.entities.serialization.View;
 
-import java.util.Date;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
-public class Room implements Entity {
+public class Room extends Entity {
 	public static class ContentGroup {
 		private List<String> contentIds;
 		private boolean autoSort;
@@ -240,10 +240,6 @@ public class Room implements Entity {
 		}
 	}
 
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
 	private String shortId;
 	private String ownerId;
 	private String name;
@@ -258,54 +254,6 @@ public class Room implements Entity {
 	private Map<String, String> attachments;
 	private RoomStatistics statistics;
 
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getId() {
-		return id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setId(final String id) {
-		this.id = id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getRevision() {
-		return rev;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setRevision(final String rev) {
-		this.rev = rev;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public String getShortId() {
 		return shortId;
@@ -438,4 +386,29 @@ public class Room implements Entity {
 	public void setStatistics(final RoomStatistics statistics) {
 		this.statistics = statistics;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * The following fields of <tt>Room</tt> are excluded from equality checks:
+	 * {@link #contentGroups}, {@link #settings}, {@link #author}, {@link #poolProperties}, {@link #extensions},
+	 * {@link #attachments}, {@link #statistics}.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final Room room = (Room) o;
+
+		return closed == room.closed &&
+				Objects.equals(shortId, room.shortId) &&
+				Objects.equals(ownerId, room.ownerId) &&
+				Objects.equals(name, room.name) &&
+				Objects.equals(abbreviation, room.abbreviation) &&
+				Objects.equals(description, room.description);
+	}
 }

src/main/java/de/thm/arsnova/entities/UserProfile.java

@@ -8,9 +8,10 @@ import java.util.Date;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
-public class UserProfile implements Entity {
+public class UserProfile extends Entity {
 	public enum AuthProvider {
 		NONE,
 		UNKNOWN,
@@ -100,10 +101,6 @@ public class UserProfile implements Entity {
 		}
 	}
 
-	private String id;
-	private String rev;
-	private Date creationTimestamp;
-	private Date updateTimestamp;
 	private AuthProvider authProvider;
 	private String loginId;
 	private Date lastLoginTimestamp;
@@ -121,54 +118,6 @@ public class UserProfile implements Entity {
 		this.loginId = loginId;
 	}
 
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getId() {
-		return id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setId(final String id) {
-		this.id = id;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public String getRevision() {
-		return rev;
-	}
-
-	@Override
-	@JsonView({View.Persistence.class, View.Public.class})
-	public void setRevision(final String rev) {
-		this.rev = rev;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getCreationTimestamp() {
-		return creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setCreationTimestamp(final Date creationTimestamp) {
-		this.creationTimestamp = creationTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public Date getUpdateTimestamp() {
-		return updateTimestamp;
-	}
-
-	@Override
-	@JsonView(View.Persistence.class)
-	public void setUpdateTimestamp(final Date updateTimestamp) {
-		this.updateTimestamp = updateTimestamp;
-	}
-
 	@JsonView({View.Persistence.class, View.Public.class})
 	public AuthProvider getAuthProvider() {
 		return authProvider;
@@ -238,4 +187,25 @@ public class UserProfile implements Entity {
 	public void setExtensions(Map<String, Map<String, ?>> extensions) {
 		this.extensions = extensions;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * The following fields of <tt>UserProfile</tt> are excluded from equality checks:
+	 * {@link #account}, {@link #roomHistory}, {@link #acknowledgedMotds}, {@link #extensions}.
+	 */
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (!super.equals(o)) {
+			return false;
+		}
+		final UserProfile that = (UserProfile) o;
+
+		return authProvider == that.authProvider &&
+				Objects.equals(loginId, that.loginId) &&
+				Objects.equals(lastLoginTimestamp, that.lastLoginTimestamp);
+	}
 }

src/test/java/de/thm/arsnova/entities/EntityTest.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2018 The ARSnova Team
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package de.thm.arsnova.entities;
+
+import org.junit.Test;
+import org.springframework.core.style.ToStringCreator;
+
+import java.util.Date;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+
+/**
+ * Tests {@link Entity}'s overrides for {@link Object#hashCode()}, {@link Object#equals(Object)}, and
+ * {@link Object#toString()}.
+ *
+ * @author Daniel Gerhardt
+ */
+public class EntityTest {
+	class SomeEntity extends Entity {
+		private String testA;
+
+		public SomeEntity(String id, String rev, Date creationTimestamp, Date updateTimestamp, String testA) {
+			this.id = id;
+			this.rev = rev;
+			this.creationTimestamp = creationTimestamp;
+			this.updateTimestamp = updateTimestamp;
+			this.testA = testA;
+		}
+
+		@Override
+		public int hashCode() {
+			return hashCode(super.hashCode(), testA);
+		}
+
+		@Override
+		public ToStringCreator buildToString() {
+			return super.buildToString().append("testA", testA);
+		}
+	}
+
+	class AnotherEntity extends SomeEntity {
+		private String testB;
+
+		public AnotherEntity(String id, String rev, Date creationTimestamp, Date updateTimestamp, String testA, String testB) {
+			super(id, rev, creationTimestamp, updateTimestamp, testA);
+			this.testB = testB;
+		}
+
+		@Override
+		public int hashCode() {
+			return hashCode(super.hashCode(), testB);
+		}
+
+		@Override
+		public ToStringCreator buildToString() {
+			return super.buildToString().append("testB", testB);
+		}
+	}
+
+	@Test
+	public void testHashCode() {
+		SomeEntity entity1 = new SomeEntity("id", "rev", new Date(0), new Date(0), "test");
+		SomeEntity entity2 = new SomeEntity("id", "rev", new Date(0), new Date(0), "test");
+		SomeEntity entity3 = new SomeEntity("wrongId", "rev", new Date(0), new Date(0), "test");
+		assertEquals(entity1.hashCode(), entity2.hashCode());
+		assertNotEquals(entity1.hashCode(), entity3.hashCode());
+		AnotherEntity entity4 = new AnotherEntity("id", "rev", new Date(0), new Date(0), "someTest", "anotherTest");
+		AnotherEntity entity5 = new AnotherEntity("id", "rev", new Date(0), new Date(0), "someTest", "anotherTest");
+		AnotherEntity entity6 = new AnotherEntity("id", "rev", new Date(0), new Date(0), "someTest", "wrong");
+		assertEquals(entity4.hashCode(), entity5.hashCode());
+		assertNotEquals(entity4.hashCode(), entity6.hashCode());
+	}
+
+	@Test
+	public void testEquals() {
+		SomeEntity entity1 = new SomeEntity("id", "rev", new Date(0), new Date(0), "test");
+		SomeEntity entity2 = new SomeEntity("id", "rev", new Date(0), new Date(0), "test");
+		SomeEntity entity3 = new SomeEntity("wrongId", "rev", new Date(0), new Date(0), "test");
+		assertEquals(entity1, entity2);
+		assertNotEquals(entity1, entity3);
+	}
+
+	@Test
+	public void testToString() {
+		SomeEntity entity1 = new SomeEntity("id", "rev", new Date(0), new Date(0), "test");
+		assertThat(entity1.toString(), startsWith("[EntityTest.SomeEntity"));
+		assertThat(entity1.toString(), endsWith("testA = 'test']"));
+		AnotherEntity entity2 = new AnotherEntity("id", "rev", new Date(0), new Date(0), "someTest", "anotherTest");
+		assertThat(entity2.toString(), startsWith("[EntityTest.AnotherEntity"));
+		assertThat(entity2.toString(), endsWith("testA = 'someTest', testB = 'anotherTest']"));
+	}
+}