diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ICommunication.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ICommunication.java
new file mode 100644
index 0000000000000000000000000000000000000000..60683f26df3391e962e0a08889f0e783387b77fb
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ICommunication.java
@@ -0,0 +1,81 @@
+package unipotsdam.gf.interfaces;
+
+import unipotsdam.gf.modules.communication.model.chat.ChatMessage;
+import unipotsdam.gf.modules.communication.model.chat.ChatRoom;
+import unipotsdam.gf.modules.communication.model.user.User;
+import unipotsdam.gf.modules.communication.model.user.UserCredentials;
+import unipotsdam.gf.modules.communication.model.user.UserRegistrationInformation;
+
+import java.util.List;
+
+/**
+ * Provides connection to rocket chat
+ */
+public interface ICommunication {
+
+ /**
+ * related endpoint: https://rocket.chat/docs/developer-guides/rest-api/groups/history/
+ * get last 20 chat messages of specific chatroom
+ *
+ * @param roomId ID of room of user
+ * @return List of Chat Messages
+ */
+ List<ChatMessage> getChatHistory(String roomId);
+
+
+ /**
+ * endpoint: https://rocket.chat/docs/developer-guides/rest-api/groups/create/
+ * creates chatroom
+ *
+ * @param name chat room name
+ * @param userIds member of chat by id; can be empty
+ * @return chat room id
+ */
+ String createChatRoom(String name, List<String> userIds);
+
+
+ /**
+ * endpoint: https://rocket.chat/docs/developer-guides/rest-api/groups/invite/
+ *
+ * @param roomId chat room the user should be add to
+ * @param userId userID to add
+ * @return if user was added successfully
+ */
+ boolean addUserToChatRoom(String roomId, String userId);
+
+ /**
+ * endpoint: https://rocket.chat/docs/developer-guides/rest-api/groups/settopic/
+ *
+ * @param roomId chat room where topic should be set
+ * @param topic topic of chat room
+ * @return true, if topic was set correctly
+ */
+ boolean setChatRoomTopic(String roomId, String topic);
+
+
+ /**
+ * api: https://rocket.chat/docs/developer-guides/rest-api/groups/info/
+ * get information about the chat room
+ *
+ * @param roomId chat room id
+ * @return chat room information
+ */
+ ChatRoom getChatRoomInfo(String roomId);
+
+ /**
+ * api: https://rocket.chat/docs/developer-guides/rest-api/authentication/login/
+ *
+ * @param userCredentials username and password
+ * @return information about user, especially authtoken for later use of endpoints
+ */
+ User loginUser(UserCredentials userCredentials);
+
+ /**
+ * registers new user to rocket chat
+ *
+ * @param userRegistrationInformation registers user to rocket.chat
+ * @return user id
+ */
+ String registerUser(UserRegistrationInformation userRegistrationInformation);
+
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IContributionReview.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IContributionReview.java
new file mode 100644
index 0000000000000000000000000000000000000000..833670ba2c11c871b9dcbe9399b5e70e492ca1ea
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IContributionReview.java
@@ -0,0 +1,84 @@
+package unipotsdam.gf.interfaces;
+
+/**
+ * Interface that defines a review for a students/groups contribution
+ *
+ * A review contains a feedback text and several scales which can be rated
+ * It can also be exported to certain formats.
+ */
+public interface IContributionReview {
+
+ /**
+ * sets the reviews feedbackText.
+ *
+ * @param feedbackText
+ */
+ void setFeedbackText(String feedbackText);
+
+ /**
+ * returns the reviews feedbackText.
+ *
+ * @return feedbackText
+ */
+ String getFeedbackText();
+
+ /**
+ * adds a rating scale to the review. The scales name and the maximum value
+ * that can be selected must be provided. The function returns an ID by
+ * which the scale can be accessed.
+ *
+ * TODO: maybe address scales by their name instead?
+ *
+ * @param description
+ * @param maxValue
+ * @return scaleID
+ */
+ int addRatingScale(String description, int maxValue);
+
+ /**
+ * removes an existing scale from the review. The scale must be addressed by
+ * a scaleID that was returned when it was created.
+ *
+ * TODO: maybe not necessary anyway?
+ *
+ * @param scaleID
+ */
+ void removeRatingScale(int scaleID);
+
+ /**
+ * sets the rating of an existing scale. Will throw an
+ * IllegalArgumentException if the rating is higher than possible.
+ *
+ * @param scaleID
+ * @param rating
+ */
+ void setRatingForScale(int scaleID, int rating) throws IllegalArgumentException;
+
+ /**
+ * returns the rating of an existing scale, addressed by it's scaleID.
+ *
+ * @param scaleID
+ * @return rating
+ */
+ int getRatingOfScale(int scaleID);
+
+ /**
+ * exports (or rather serializes) the review as an object so that it can be
+ * used by other applications.
+ *
+ * TODO: think of exportTypes
+ * @param exportType
+ * @return this object in another format
+ */
+ String exportAs(String exportType);
+
+ /**
+ * override for toString. Might just call .exportAs() internally
+ * @return this objects String representation. Maybe not necessary, but nice
+ * for sure.
+ */
+ @Override
+ String toString();
+
+
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IJournal.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IJournal.java
new file mode 100644
index 0000000000000000000000000000000000000000..af88032ca1d32d94023eed01af4a3fc4fd9c59f4
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IJournal.java
@@ -0,0 +1,63 @@
+package unipotsdam.gf.interfaces;
+
+import unipotsdam.gf.modules.journal.JournalEntry;
+
+/**
+ * Interface for learning journal entry
+ */
+public interface IJournal {
+
+ /**
+ * Enum for visibility
+ */
+ enum Visibility{ALL, STUDENT, DOZENT, NONE}
+
+
+ /**
+ * Add a new journal entry
+ *
+ * @param text text of the entry
+ * @param visibility visibility of the entry
+ */
+ void addJournal(String text, Visibility visibility);
+
+ /**
+ * Change an existing journal entry
+ *
+ * @param newText the new text
+ */
+ void editJournal(String newText);
+
+ /**
+ * Delete a journal entry
+ *
+ * @param journaId id of the entry
+ */
+ void deleteJournal(long journaId);
+
+ /**
+ * change visibility of an entry
+ * @param journaId id of the entry
+ * @param visibility new visibility
+ */
+ void setVisibility(long journaId, Visibility visibility);
+
+ /**
+
+ * Get specific journal entry
+ *
+ * @param journaId id of the entry
+ * @return JournalEntry from database
+ */
+ JournalEntry getJournal(long journaId);
+
+ /**
+ * Get all JournalEntry for a project
+ *
+ * @param projectId id of project
+ * @return all JournalEnrys for that project
+ */
+ JournalEntry getAllJournalEntrysProject(long projectId);
+
+
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IProjectDescription.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IProjectDescription.java
new file mode 100644
index 0000000000000000000000000000000000000000..cc89a2870180ac12f5aaf13668e3291e3e63bcd6
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/IProjectDescription.java
@@ -0,0 +1,67 @@
+package unipotsdam.gf.interfaces;
+
+import java.util.ArrayList;
+
+/**
+ * Interface for Project Description
+ */
+public interface IProjectDescription {
+
+ /**
+ * Save description to database
+ * @param description
+ */
+ void saveDescription(String description);
+
+ /**
+ * Add a new link to ProjectDescription
+ * @param link url of the link
+ * @param name name to shoe on website
+ */
+ void addLink(String link, String name);
+
+ /**
+ * Delete link
+ * @param name name of the link
+ */
+ void deleteLink(String name);
+
+ /**
+ * Get name of the project
+ * @param projectId Id of the project
+ * @return name of the project
+ */
+
+ String getName(long projectId);
+
+ /**
+ * Get Description of the project
+ * @param projectId Id of the project
+ * @return Desription of the project
+ */
+ String getDescription(long projectId);
+
+ /**
+ * Get Lecturer of the project
+ * @param projectId Id of the project
+ * @return Lecturer of the project
+ */
+ long getLecturer(long projectId);
+
+ /**
+ * Get all Students of the project (Group)
+ * @param projectId Id of the Project
+ * @return Students of the project
+ */
+ ArrayList<Long> getStudents(long projectId);
+
+ /**
+ * Get all Links of the project
+ * @param projectId Id of the Project
+ * @return all links of the project
+ */
+ ArrayList<Long> getLinks(long projectId);
+
+
+
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ResearchReport.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ResearchReport.java
index f4d466100439a28ddcec7405f47b4dd778276bfd..a35936a46c5fd0facbb0c39d252e55740e3f2cc8 100644
--- a/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ResearchReport.java
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/interfaces/ResearchReport.java
@@ -1,5 +1,5 @@
package unipotsdam.gf.interfaces;
-
+import java.io.*;
/**
* Created by Johannes Zeiße on 30.05.2018.
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/chat/ChatMessage.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/chat/ChatMessage.java
new file mode 100644
index 0000000000000000000000000000000000000000..eb28777f80350922a2dd291b690e0d7134a15504
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/chat/ChatMessage.java
@@ -0,0 +1,52 @@
+package unipotsdam.gf.modules.communication.model.chat;
+
+import java.time.Instant;
+
+public class ChatMessage {
+
+ String id;
+ String message;
+ Instant timestamp;
+ String username;
+
+ public ChatMessage() {}
+
+ public ChatMessage(String id, String message, Instant timestamp, String username) {
+ this.id = id;
+ this.message = message;
+ this.timestamp = timestamp;
+ this.username = username;
+ }
+
+ public String getId() {
+ return id;
+ }
+
+ public void setId(String id) {
+ this.id = id;
+ }
+
+ public String getMessage() {
+ return message;
+ }
+
+ public void setMessage(String message) {
+ this.message = message;
+ }
+
+ public Instant getTimestamp() {
+ return timestamp;
+ }
+
+ public void setTimestamp(Instant timestamp) {
+ this.timestamp = timestamp;
+ }
+
+ public String getUsername() {
+ return username;
+ }
+
+ public void setUsername(String username) {
+ this.username = username;
+ }
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/chat/ChatRoom.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/chat/ChatRoom.java
new file mode 100644
index 0000000000000000000000000000000000000000..0a97bfcaa8956ee862866c8cb1df48335a9301ed
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/chat/ChatRoom.java
@@ -0,0 +1,30 @@
+package unipotsdam.gf.modules.communication.model.chat;
+
+public class ChatRoom {
+
+ String id;
+ String name;
+
+ public ChatRoom() {}
+
+ public ChatRoom(String id, String name) {
+ this.id = id;
+ this.name = name;
+ }
+
+ public String getId() {
+ return id;
+ }
+
+ public void setId(String id) {
+ this.id = id;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public void setName(String name) {
+ this.name = name;
+ }
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/User.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/User.java
new file mode 100644
index 0000000000000000000000000000000000000000..92914711702ca737194fd2c15544f3b6f9ab0909
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/User.java
@@ -0,0 +1,30 @@
+package unipotsdam.gf.modules.communication.model.user;
+
+public class User {
+
+ String id;
+ String authToken;
+
+ public User() {}
+
+ public User(String id, String authToken) {
+ this.id = id;
+ this.authToken = authToken;
+ }
+
+ public String getId() {
+ return id;
+ }
+
+ public void setId(String id) {
+ this.id = id;
+ }
+
+ public String getAuthToken() {
+ return authToken;
+ }
+
+ public void setAuthToken(String authToken) {
+ this.authToken = authToken;
+ }
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/UserCredentials.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/UserCredentials.java
new file mode 100644
index 0000000000000000000000000000000000000000..97ec8969ce07f4268ed61496aefd6d4baf9a1f45
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/UserCredentials.java
@@ -0,0 +1,30 @@
+package unipotsdam.gf.modules.communication.model.user;
+
+public class UserCredentials {
+
+ String username;
+ String password;
+
+ public UserCredentials() {}
+
+ public UserCredentials(String username, String password) {
+ this.username = username;
+ this.password = password;
+ }
+
+ public String getUsername() {
+ return username;
+ }
+
+ public void setUsername(String username) {
+ this.username = username;
+ }
+
+ public String getPassword() {
+ return password;
+ }
+
+ public void setPassword(String password) {
+ this.password = password;
+ }
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/UserRegistrationInformation.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/UserRegistrationInformation.java
new file mode 100644
index 0000000000000000000000000000000000000000..b109f1f66c64331254491af5eddaa50f35a6f032
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/communication/model/user/UserRegistrationInformation.java
@@ -0,0 +1,41 @@
+package unipotsdam.gf.modules.communication.model.user;
+
+public class UserRegistrationInformation {
+
+ private String username;
+ private String email;
+ private String pass;
+ private String name;
+
+ public String getUsername() {
+ return username;
+ }
+
+ public void setUsername(String username) {
+ this.username = username;
+ }
+
+ public String getEmail() {
+ return email;
+ }
+
+ public void setEmail(String email) {
+ this.email = email;
+ }
+
+ public String getPass() {
+ return pass;
+ }
+
+ public void setPass(String pass) {
+ this.pass = pass;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public void setName(String name) {
+ this.name = name;
+ }
+}
diff --git a/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/journal/JournalEntry.java b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/journal/JournalEntry.java
new file mode 100644
index 0000000000000000000000000000000000000000..496f0418ec8da00214b8d27c5061b691508bf9c4
--- /dev/null
+++ b/gemeinsamforschen/src/main/java/unipotsdam/gf/modules/journal/JournalEntry.java
@@ -0,0 +1,89 @@
+package unipotsdam.gf.modules.journal;
+
+import unipotsdam.gf.interfaces.IJournal;
+
+/**
+ * Prototype of JournalEntry Class
+ */
+public class JournalEntry {
+
+ long id;
+ long owner;
+ long project;
+ long timestamp;
+ IJournal.Visibility visibility;
+ String text;
+
+
+ public JournalEntry() {
+ }
+
+ public JournalEntry(long id, long owner, long project, long timestamp, IJournal.Visibility visibility, String text) {
+ this.id = id;
+ this.owner = owner;
+ this.project = project;
+ this.timestamp = timestamp;
+ this.visibility = visibility;
+ this.text = text;
+ }
+
+ public long getId() {
+ return id;
+ }
+
+ public void setId(long id) {
+ this.id = id;
+ }
+
+ public long getOwner() {
+ return owner;
+ }
+
+ public void setOwner(long owner) {
+ this.owner = owner;
+ }
+
+ public long getProject() {
+ return project;
+ }
+
+ public void setProject(long project) {
+ this.project = project;
+ }
+
+ public long getTimestamp() {
+ return timestamp;
+ }
+
+ public void setTimestamp(long timestamp) {
+ this.timestamp = timestamp;
+ }
+
+ public IJournal.Visibility getVisibility() {
+ return visibility;
+ }
+
+ public void setVisibility(IJournal.Visibility visibility) {
+ this.visibility = visibility;
+ }
+
+ public String getText() {
+ return text;
+ }
+
+ public void setText(String text) {
+ this.text = text;
+ }
+
+ @Override
+ public String toString() {
+ return "JournalEntry{" +
+ "id=" + id +
+ ", owner=" + owner +
+ ", project=" + project +
+ ", timestamp=" + timestamp +
+ ", visibility=" + visibility +
+ ", text='" + text + '\'' +
+ '}';
+ }
+}