diff --git a/pom.xml b/pom.xml
index c038e26..71835cf 100644
--- a/pom.xml
+++ b/pom.xml
@@ -54,11 +54,6 @@
             <version>4.12.1</version>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.testifyproject.mock</groupId>
-            <artifactId>mockito</artifactId>
-            <version>1.0.4</version>
-        </dependency>
     </dependencies>
 
 </project>
\ No newline at end of file
diff --git a/src/main/java/de/joethei/hs/java2/praktikum/praktikum1/GrosseZahl.java b/src/main/java/de/joethei/hs/java2/praktikum/praktikum1/GrosseZahl.java
index ba94468..9a3efab 100644
--- a/src/main/java/de/joethei/hs/java2/praktikum/praktikum1/GrosseZahl.java
+++ b/src/main/java/de/joethei/hs/java2/praktikum/praktikum1/GrosseZahl.java
@@ -68,7 +68,6 @@ public class GrosseZahl {
         if(this.equals(b)) {
             return new GrosseZahl(0);
         } else if(this.less(b)) {
-            System.out.println("sub() kann keine negativen Werte zurückgeben.");
             return new GrosseZahl(0);
         }
         GrosseZahl rueckgabe = new GrosseZahl(this.toString());
diff --git a/src/main/java/de/joethei/hs/java2/praktikum/praktikum4/KlausurenServer.java b/src/main/java/de/joethei/hs/java2/praktikum/praktikum4/KlausurenServer.java
index 10c46e1..8583a2a 100644
--- a/src/main/java/de/joethei/hs/java2/praktikum/praktikum4/KlausurenServer.java
+++ b/src/main/java/de/joethei/hs/java2/praktikum/praktikum4/KlausurenServer.java
@@ -2,22 +2,22 @@ package de.joethei.hs.java2.praktikum.praktikum4;
 
 import java.io.IOException;
 import java.net.ServerSocket;
-import java.net.Socket;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
+import java.util.concurrent.*;
 
 public class KlausurenServer {
 
     private ConcurrentMap<String, TreeSet<Integer>> data = new ConcurrentHashMap<>();
     private static ExecutorService executorService = Executors.newCachedThreadPool();
+    private static ServerSocket serverSocket;
+
     private static Map<String, CommandHandler> commands = new HashMap<>();
 
+    private boolean running;
+
     public KlausurenServer(int port) {
         commands.put("test", ((writer, args) -> writer.write("Hallo Welt")));
         commands.put("put", (writer, args) -> {
@@ -65,18 +65,26 @@ public class KlausurenServer {
         });
         commands.put("stop", ((writer, args) -> {
             writer.write("1");
-            executorService.shutdown();
-            System.exit(0);
+            running = false;
         }));
-
+        running = true;
         Runnable runnable = () -> {
             try {
-                ServerSocket serverSocket = new ServerSocket(port);
+                serverSocket = new ServerSocket(port);
                 System.out.println("waiting for clients");
-                while (true) {
-                    Socket clientSocket = serverSocket.accept();
-                    executorService.submit(new ClientRunnable(clientSocket));
+                while (running) {
+                    executorService.submit(new ClientRunnable(serverSocket.accept()));
                 }
+                executorService.shutdown();
+                try {
+                    executorService.awaitTermination(10, TimeUnit.MINUTES);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+                serverSocket.close();
+                System.out.println("server shutdown");
+                Thread.currentThread().interrupt();
             } catch (IOException e) {
                 e.printStackTrace();
             }
diff --git a/src/main/resources/praktikum4/data b/src/main/resources/praktikum4/data
new file mode 100644
index 0000000..e69de29
diff --git a/src/test/java/de/joethei/hs/java2/tests/KlausurenServerTest.java b/src/test/java/de/joethei/hs/java2/tests/KlausurenServerTest.java
index 48d43ae..638ca94 100644
--- a/src/test/java/de/joethei/hs/java2/tests/KlausurenServerTest.java
+++ b/src/test/java/de/joethei/hs/java2/tests/KlausurenServerTest.java
@@ -13,9 +13,11 @@ import static org.junit.Assert.assertEquals;
 @RunWith(OrderedRunner.class)
 public class KlausurenServerTest {
 
+    private static KlausurenServer server;
+
     @BeforeClass
     public static void before() {
-        new KlausurenServer(6767);
+       server = new KlausurenServer(6767);
     }
 
     @Test
@@ -29,6 +31,7 @@ public class KlausurenServerTest {
     public void put() {
         assertEquals("1", sendRequest("put max@maier 6, 5"));
         assertEquals("1 5, 6", sendRequest("put max@maier 7,8"));
+        assertEquals("0", sendRequest("put max@maier"));
     }
 
     @Test(timeout = 60L)
@@ -49,8 +52,20 @@ public class KlausurenServerTest {
     public void del() {
         assertEquals("0", sendRequest("del max@maier baum"));
         assertEquals("1 5, 6, 7, 8", sendRequest("del max@maier"));
+        assertEquals("0", sendRequest("get max@maier"));
     }
 
+    /*
+    @Test(timeout = 700L)
+    @Order(order = 6)
+    public void saved() throws InterruptedException {
+        assertEquals("1", sendRequest("stop"));
+        Thread.sleep(500L);
+        server = new KlausurenServer(6767);
+        assertEquals("1 [5, 6, 7, 8]", sendRequest("getall"));
+    }
+    */
+
     private String sendRequest(String command) {
         try {
             Socket socket = new Socket("localhost", 6767);