diff -r 0f4f8f255c32 -r fecda0f466e6 src/main/java/de/uapcore/lightpit/entities/User.java
--- a/src/main/java/de/uapcore/lightpit/entities/User.java	Sun May 10 10:11:37 2020 +0200
+++ b/src/main/java/de/uapcore/lightpit/entities/User.java	Sun May 10 10:58:31 2020 +0200
@@ -28,23 +28,26 @@
  */
 package de.uapcore.lightpit.entities;
 
+import java.util.Objects;
+
 public final class User {
 
     public static final int ANONYMOUS_USERID = -1;
 
-    private int userID;
+    private final int userID;
     private String username;
+    private String mail;
     private String givenname;
     private String lastname;
 
+    public User(int userID) {
+        this.userID = userID;
+    }
+
     public int getUserID() {
         return userID;
     }
 
-    public void setUserID(int userID) {
-        this.userID = userID;
-    }
-
     public String getUsername() {
         return username;
     }
@@ -53,6 +56,14 @@
         this.username = username;
     }
 
+    public String getMail() {
+        return mail;
+    }
+
+    public void setMail(String mail) {
+        this.mail = mail;
+    }
+
     public String getGivenname() {
         return givenname;
     }
@@ -70,21 +81,15 @@
     }
 
     @Override
-    public int hashCode() {
-        int hash = 3;
-        hash = 41 * hash + this.userID;
-        return hash;
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        User user = (User) o;
+        return userID == user.userID;
     }
 
     @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj == null || getClass() != obj.getClass()) {
-            return false;
-        } else {
-            return this.userID == ((User) obj).userID;
-        }
+    public int hashCode() {
+        return Objects.hash(userID);
     }
 }