diff --git a/app/src/main/java/lightcontainer/storage/Adapter.java b/app/src/main/java/lightcontainer/storage/Adapter.java
index 29d5dc3..804f163 100644
--- a/app/src/main/java/lightcontainer/storage/Adapter.java
+++ b/app/src/main/java/lightcontainer/storage/Adapter.java
@@ -1,8 +1,8 @@
 package lightcontainer.storage;
 
 public interface Adapter {
-    
-    String toString();
+
+    String toString(AppData appData);
 
     AppData fromString(String appDataString);
 }
diff --git a/app/src/main/java/lightcontainer/storage/JsonAdapter.java b/app/src/main/java/lightcontainer/storage/JsonAdapter.java
index dcf09c3..4cb8060 100644
--- a/app/src/main/java/lightcontainer/storage/JsonAdapter.java
+++ b/app/src/main/java/lightcontainer/storage/JsonAdapter.java
@@ -9,18 +9,11 @@ import java.util.*;
  */
 public class JsonAdapter implements Adapter {
 
-    private AppData appData;
-
-    public JsonAdapter(AppData appData) {
-        this.appData = appData;
-    }
-
     /**
-     *
      * @return A Json String containing AppData properties
      */
     @Override
-    public String toString() {
+    public String toString(AppData appData) {
         return addData(appData);
     }
 
@@ -77,7 +70,6 @@ public class JsonAdapter implements Adapter {
     }
 
     /**
-     *
      * @param appDataString The Json String to convert
      * @return An AppData instance
      */
@@ -100,8 +92,7 @@ public class JsonAdapter implements Adapter {
             for (User user : users) {
                 appData.addUser(user.getName(), user.getPassword(), user.getAesKey());
             }
-            this.appData = appData;
-            return this.appData;
+            return appData;
         } catch (JsonParseException parseException) {
             System.out.println("[FFE] : Error while loading configuration file"); //TODO - changer en log
             return null;
diff --git a/app/src/main/java/lightcontainer/storage/Repository.java b/app/src/main/java/lightcontainer/storage/Repository.java
index 27457a5..324b125 100644
--- a/app/src/main/java/lightcontainer/storage/Repository.java
+++ b/app/src/main/java/lightcontainer/storage/Repository.java
@@ -12,13 +12,15 @@ public class Repository {
 
     private final String filePath;
     private final Adapter adapter;
+    private final AppData appData;
 
     /**
      * @param filePath The path to the configuration file
      * @param adapter  The adapter that converts objects to string and vice-versa
      */
-    public Repository(String filePath, Adapter adapter) {
+    public Repository(String filePath, AppData appData, Adapter adapter) {
         this.filePath = filePath;
+        this.appData = appData;
         this.adapter = adapter;
     }
 
diff --git a/app/src/test/java/lightcontainer/storage/JsonAdapterTests.java b/app/src/test/java/lightcontainer/storage/JsonAdapterTests.java
index dc87270..d00a0eb 100644
--- a/app/src/test/java/lightcontainer/storage/JsonAdapterTests.java
+++ b/app/src/test/java/lightcontainer/storage/JsonAdapterTests.java
@@ -22,17 +22,15 @@ public class JsonAdapterTests {
         appConfig.setMulticastPort(15502);
         appConfig.setNetworkInterface("My network interface");
         appConfig.setTls(false);
-        Map<String, File> files = new HashMap<>();
         Set<String> storage = new HashSet<>();
         storage.add("StorBackEnd1");
         File file1 = new File("File1", 15, "8d8d8d8d", storage);
-        files.put(file1.getName(), file1);
-        User user1 = new User("User1", "Password", "djdjjdj", files);
         appData.setAppConfig(appConfig);
-        //appData.addUser(user1);
-        JsonAdapter jsonAdapter = new JsonAdapter(appData);
+        appData.addUser("User1", "Password","djdjjdj");
+        appData.addFileFor(file1, "User1");
+        JsonAdapter jsonAdapter = new JsonAdapter();
         //WHEN the adapter converts AppData to Json
-        String jsonAppData = jsonAdapter.toString();
+        String jsonAppData = jsonAdapter.toString(appData);
         //THEN
         assertTrue(jsonAppData.contains("32000"));
         assertTrue(jsonAppData.contains("224.25.0.1"));
@@ -53,7 +51,7 @@ public class JsonAdapterTests {
         //GIVEN a Json string
         String json = "{\"unicast_port\":32000,\"multicast_ip\":\"224.25.0.1\",\"multicast_port\":15502,\"network_interface\":\"My network interface\",\"tls\":false,\"users\":[{\"name\":\"User1\",\"password\":\"Password\",\"aes_key\":\"djdjjdj\",\"files\":[{\"name\":\"File1\",\"size\":15,\"iv\":\"8d8d8d8d\",\"storage\":[\"StorBackEnd1\"]}]}]}";
         //WHEN the adapter converts Json to Appdata
-        JsonAdapter jsonAdapter = new JsonAdapter(null);
+        JsonAdapter jsonAdapter = new JsonAdapter();
         AppData appData = jsonAdapter.fromString(json);
         //THEN
         assertNotNull(appData.getAppConfig());
diff --git a/app/src/test/java/lightcontainer/storage/RepositoryTests.java b/app/src/test/java/lightcontainer/storage/RepositoryTests.java
index 543ee54..5f96ea5 100644
--- a/app/src/test/java/lightcontainer/storage/RepositoryTests.java
+++ b/app/src/test/java/lightcontainer/storage/RepositoryTests.java
@@ -40,11 +40,11 @@ public class RepositoryTests {
         File file1 = new File("File1", 15, "8d8d8d8d", storage);
         appData.setAppConfig(appConfig);
         appData.addUser("User1", "Password", "djdjjdj");
-        JsonAdapter jsonAdapter = new JsonAdapter(appData);
+        JsonAdapter jsonAdapter = new JsonAdapter();
         appData.addFileFor(file1, "User1");
         //WHEN Repository calls save method
         String filePath = "src/test/resources/test.json";
-        Repository repository = new Repository(filePath, jsonAdapter);
+        Repository repository = new Repository(filePath, appData, jsonAdapter);
         repository.save();
         //THEN
         assertTrue(Files.exists(Paths.get("src/test/resources/test.json").toAbsolutePath()));
@@ -53,9 +53,9 @@ public class RepositoryTests {
     @Test
     public void load() {
         //GIVEN a test json file loadTest.json
-        JsonAdapter jsonAdapter = new JsonAdapter(null);
+        JsonAdapter jsonAdapter = new JsonAdapter();
         //WHEN repository calls load method
-        Repository repository = new Repository("src/test/resources/loadTest.json", jsonAdapter);
+        Repository repository = new Repository("src/test/resources/loadTest.json", AppData.getInstance(), jsonAdapter);
         AppData appData = repository.load();
         //THEN
         assertNotNull(appData.getAppConfig());