unfinished code

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesList.java

@@ -115,10 +115,10 @@ public class ModulesList extends HTTPService {
             this.upgrade(success -> {
                 if (this.mModules == null)
                     this.mModules = success;
-                else
-                    this.mModules.updateList(success);
-                mListener.onModuleListChange();
-                store();
+                else if (this.mModules.updateList(success)) {
+                    mListener.onModuleListChange();
+                    store();
+                }
                 callback.onResponse(this.mModules);
                 mQueue.next();
             }, error -> {

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Announcement.java

@@ -2,12 +2,16 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.ArrayList;
+import java.util.HashSet;
 
 import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Announcement implements Serializable {
+public class Announcement implements UtilsJson.JsonConvertible {
     private final String id;
     private final String title;
     private final String body;
@@ -24,6 +28,19 @@ public class Announcement implements Serializable {
         this.urls = urls;
     }
 
+    public Announcement(JSONObject json) throws JSONException {
+        this.id = json.getString("id");
+        this.title = json.getString("title");
+        this.body = json.getString("body");
+        this.createdBy = json.getString("createdBy");
+        this.createdOn = json.getLong("createdOn");
+        ArrayList<String> urls = new ArrayList<>();
+        for (String url: UtilsJson.jsonArrayToIterableString(json.getJSONArray("urls"))) {
+            urls.add(url);
+        }
+        this.urls = urls;
+    }
+
     public ArrayList<String> getUrls() {
         return urls;
     }
@@ -63,4 +80,16 @@ public class Announcement implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getId(), getBody(), getCreatedBy(), getCreatedOn(), getTitle(), getUrls());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("id", id);
+        json.put("title", title);
+        json.put("body", body);
+        json.put("createdBy", createdBy);
+        json.put("createdOn", createdOn);
+        json.put("urls", UtilsJson.collectionToJson(urls));
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Assignment.java

@@ -2,12 +2,15 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.ArrayList;
 
 import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Assignment implements Serializable {
+public class Assignment implements UtilsJson.JsonConvertible {
     private final String id;
     private final String title;
     private final long dueTime;
@@ -59,4 +62,15 @@ public class Assignment implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getId(), getDueDate(), getInstructions(), getTitle(), getUrls());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("id", id);
+        json.put("title", title);
+        json.put("dueTime", dueTime);
+        json.put("createdBy", UtilsJson.collectionToJson(urls));
+        json.put("instructions", instructions);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Event.java

@@ -2,15 +2,18 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
 import androidx.annotation.NonNull;
 import de.sebse.fuplanner.tools.ColorRGB;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Event implements Serializable {
+public class Event implements UtilsJson.JsonConvertible {
     private final String siteId;
     private final String id;
     private final String type;
@@ -120,4 +123,17 @@ public class Event implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getId(), getType(), getStartDate(), getEndDate(), getTitle(), getLocation());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("siteId", siteId);
+        json.put("id", id);
+        json.put("type", type);
+        json.put("title", title);
+        json.put("duration", duration);
+        json.put("firstTime", firstTime);
+        json.put("location", location);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Grade.java

@@ -2,11 +2,13 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Grade implements Serializable {
+public class Grade implements UtilsJson.JsonConvertible {
     private final String itemName;
     private final double grade;
     private final double maxPoints;
@@ -41,4 +43,13 @@ public class Grade implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getItemName(), getPoints(), getMaxPoints());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("itemName", itemName);
+        json.put("grade", grade);
+        json.put("maxPoints", maxPoints);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Lecturer.java

@@ -1,12 +1,17 @@
 package de.sebse.fuplanner.services.kvv.types;
 
-import java.io.Serializable;
+import com.google.android.gms.common.internal.Objects;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Lecturer implements Serializable {
+public class Lecturer implements UtilsJson.JsonConvertible {
     private final String firstName;
     private final String surname;
     private final String mail;
@@ -24,6 +29,13 @@ public class Lecturer implements Serializable {
         this.isResponsible = matcher.group(4).equals("true");
     }
 
+    public Lecturer(JSONObject json) throws JSONException {
+        this.firstName = json.getString("firstName");
+        this.surname = json.getString("surname");
+        this.mail = json.getString("mail");
+        this.isResponsible = json.getBoolean("isResponsible");
+    }
+
     public String getFirstName() {
         return firstName;
     }
@@ -55,4 +67,19 @@ public class Lecturer implements Serializable {
                 "\nSurname: "+getSurname()+
                 "\nMail: "+getMail();
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(getFirstName(), getSurname(), getMail(), isResponsible());
+    }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("firstName", firstName);
+        json.put("surname", surname);
+        json.put("mail", mail);
+        json.put("isResponsible", isResponsible);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/LoginToken.java

@@ -19,10 +19,7 @@ import de.sebse.fuplanner.tools.logging.Logger;
  * Created by sebastian on 29.10.17.
  */
 
-public class LoginToken implements Serializable {
-    static Logger log = new Logger("LoginToken");
-    private static final String FILE_NAME = "LoginTokenSaving";
-
+public class LoginToken {
     private final String username;
     private final String shibsessionKey;
     private final String shibsessionName;

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Modules.java

@@ -2,14 +2,23 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import android.content.Context;
 
-import org.jetbrains.annotations.NotNull;
+import com.google.android.gms.common.internal.Objects;
 
+import org.jetbrains.annotations.NotNull;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.BufferedReader;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
-import java.io.Serializable;
+import java.io.OutputStreamWriter;
+import java.lang.reflect.Array;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -17,16 +26,22 @@ import java.util.LinkedHashSet;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import de.sebse.fuplanner.tools.UtilsJson;
+
+import static de.sebse.fuplanner.tools.UtilsJson.collectionToJson;
+import static de.sebse.fuplanner.tools.UtilsJson.jsonArrayToIterableObject;
 
 /**
  * Created by sebastian on 29.10.17.
  */
 
-public class Modules implements Iterable<Modules.Module>, Serializable {
+public class Modules implements Iterable<Modules.Module> {
     private SortedListModule list;
     private final String mUsername;
+    private long mLoadTime;
     //private transient Logger log = new Logger(this);
     private static final String FILE_NAME = "ModuleListSaving";
+    private static final String FILE_NAME_TIMESTAMP = "ModuleListSavingTimestamp";
 
     public Modules(String username) {
         this.mUsername = username;
@@ -66,24 +81,54 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
         return this.list.get(index);
     }
 
-    public static Modules load(Context context) throws IOException, ClassNotFoundException {
-        FileInputStream fis = context.openFileInput(FILE_NAME);
-        ObjectInputStream is = new ObjectInputStream(fis);
-        Object readObject = is.readObject();
-        if (!(readObject instanceof Modules))
-            return null;
-        Modules modules = (Modules) readObject;
-        is.close();
-        fis.close();
-        return modules;
+    public static Modules load(Context context) throws IOException {
+        String ret = "";
+        InputStream inputStream = context.openFileInput(FILE_NAME);
+        if (inputStream != null) {
+            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
+            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
+            String receiveString;
+            StringBuilder stringBuilder = new StringBuilder();
+            while ((receiveString = bufferedReader.readLine()) != null) {
+                stringBuilder.append(receiveString);
+            }
+            inputStream.close();
+            ret = stringBuilder.toString();
+        }
+
+        try {
+            JSONObject json = new JSONObject(ret);
+            Modules mod = new Modules(json.getString("username"));
+            JSONArray arr = json.getJSONArray("modules");
+            for (JSONObject jsonObject: jsonArrayToIterableObject(arr)) {
+                mod.list.add(new Module(jsonObject));
+            }
+            FileInputStream ofi = context.openFileInput(FILE_NAME_TIMESTAMP);
+            ObjectInputStream inputStream1 = new ObjectInputStream(ofi);
+            mod.mLoadTime = inputStream1.readLong();
+            return mod;
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+        return null;
     }
 
     public void save(Context context) throws IOException {
-        FileOutputStream fos = context.openFileOutput(FILE_NAME, Context.MODE_PRIVATE);
-        ObjectOutputStream os = new ObjectOutputStream(fos);
-        os.writeObject(this);
-        os.close();
-        fos.close();
+        JSONObject json = new JSONObject();
+        try {
+            json.put("username", mUsername);
+            json.put("modules", UtilsJson.collectionToJson(list));
+            OutputStreamWriter osw = new OutputStreamWriter(context.openFileOutput(FILE_NAME, Context.MODE_PRIVATE));
+            osw.write(json.toString());
+            osw.close();
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+
+        mLoadTime = System.currentTimeMillis();
+        FileOutputStream ofo = context.openFileOutput(FILE_NAME_TIMESTAMP, Context.MODE_PRIVATE);
+        ObjectOutputStream outputStream = new ObjectOutputStream(ofo);
+        outputStream.writeLong(mLoadTime);
     }
 
     public void delete(Context context) {
@@ -94,27 +139,41 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
         return mUsername;
     }
 
-    public void updateList(Modules modules) {
+    public boolean updateList(Modules modules) {
         SortedListModule old = this.list;
         this.list = modules.list;
+        boolean isChanged = false;
         for (Module oldModule : old) {
             Module newModule = this.list.getById(oldModule.getID());
             if (newModule != null) {
+                if (!isChanged && !hashEquals(oldModule, newModule))
+                    isChanged = true;
                 newModule.announcements = oldModule.announcements;
                 newModule.assignments = oldModule.assignments;
                 newModule.events = oldModule.events;
                 newModule.gradebook = oldModule.gradebook;
                 newModule.resources = oldModule.resources;
+            } else {
+                isChanged = true;
             }
         }
+        return isChanged;
     }
 
-    public class Module implements Serializable {
+    private boolean hashEquals(Module o1, Module o2) {
+        if (o1 == null && o2 == null)
+            return true;
+        else if (o1 == null || o2 == null)
+            return false;
+        else
+            return o1.hashCode() == o2.hashCode();
+    }
+
+    public static class Module implements UtilsJson.JsonConvertible {
         @Nullable public final Semester semester;
         @NotNull final HashSet<String> lvNumber;
         @NotNull public final String title;
-        @NotNull
-        public final ArrayList<Lecturer> lecturer;
+        @NotNull public final ArrayList<Lecturer> lecturer;
         @Nullable public final String type;
         @Nullable public final String description;
         @NotNull private final String ID;
@@ -124,6 +183,29 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
         @Nullable public ArrayList<Grade> gradebook;
         @Nullable public ArrayList<Resource> resources;
 
+        @Override
+        public int hashCode() {
+            return Objects.hashCode(semester, lvNumber, title, lecturer, type, description, ID);
+        }
+
+        @Override
+        public JSONObject toJSONObject() throws JSONException {
+            JSONObject json = new JSONObject();
+            json.put("semester", semester != null ? semester.toJSONObject() : null);
+            json.put("lvNumber", collectionToJson(lvNumber));
+            json.put("title", title);
+            json.put("lecturer", collectionToJson(lecturer));
+            json.put("type", type);
+            json.put("description", description);
+            json.put("ID", ID);
+            json.put("announcements", collectionToJson(announcements));
+            json.put("assignments", collectionToJson(assignments));
+            json.put("events", collectionToJson(events));
+            json.put("gradebook", collectionToJson(gradebook));
+            json.put("resources", collectionToJson(resources));
+            return json;
+        }
+
         public float getGradebookPercent(){
             float maxPoint = 0;
             float userPoint = 0;
@@ -151,6 +233,71 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
             this.ID = ID;
         }
 
+        private Module(@NotNull JSONObject json) throws JSONException {
+            HashSet<String> lv = new HashSet<>();
+            for (String number: UtilsJson.jsonArrayToIterableString(json.getJSONArray("lvNumber"))) {
+                lv.add(number);
+            }
+            LinkedHashSet<Lecturer> lecturer = new LinkedHashSet<>();
+            for (JSONObject l: UtilsJson.jsonArrayToIterableObject(json.getJSONArray("lecturer"))) {
+                lecturer.add(new Lecturer(l));
+            }
+            JSONObject obj = json.optJSONObject("semester");
+
+            this.semester = obj != null ? new Semester(obj) : null;
+            this.lvNumber = lv;
+            this.title = json.getString("title");
+            this.lecturer = new ArrayList<>(lecturer);
+            this.type = json.getString("type");
+            this.description = json.getString("description");
+            this.ID = json.getString("ID");
+
+            JSONArray arr = json.optJSONArray("announcements");
+            if (obj != null) {
+                ArrayList<Announcement> announce = new ArrayList<>();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    announce.add(new Announcement(l));
+                }
+                this.announcements = announce;
+            }
+            arr = json.optJSONArray("assignments");
+            if (obj != null) {
+                AssignmentList assign = new AssignmentList();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    assign.add(new Assignment(l));
+                }
+                this.assignments = assign;
+            }
+
+            arr = json.optJSONArray("events");
+            if (obj != null) {
+                EventList events = new EventList();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    events.add(new Event(l));
+                }
+                this.events = events;
+            }
+            arr = json.optJSONArray("gradebook");
+            if (obj != null) {
+                ArrayList<Grade> grades = new ArrayList<>();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    grades.add(new Grade(l));
+                }
+                this.gradebook = grades;
+            }
+            arr = json.optJSONArray("resources");
+            if (obj != null) {
+                ArrayList<Resource> res = new ArrayList<>();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    if (l.getString("restype").equals("file"))
+                        res.add(new Resource.File(l));
+                    else
+                        res.add(new Resource.Folder(l));
+                }
+                this.resources = res;
+            }
+        }
+
         @NonNull
         public String getID() {
             return ID;

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Resource.java

@@ -2,17 +2,20 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.ArrayList;
 
 import androidx.annotation.LayoutRes;
 import androidx.annotation.NonNull;
 import de.sebse.fuplanner.R;
+import de.sebse.fuplanner.tools.UtilsJson;
 import de.sebse.fuplanner.tools.ui.treeview.LayoutItemType;
 import de.sebse.fuplanner.tools.ui.treeview.TreeNode;
 
 
-public abstract class Resource implements Serializable {
+public abstract class Resource implements UtilsJson.JsonConvertible {
 
     final String author;
     final long modifiedDate;
@@ -62,6 +65,19 @@ public abstract class Resource implements Serializable {
         return Objects.hashCode(getAuthor(), getContainer(), getModifiedDate(), getTitle(), getUrl());
     }
 
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("author", author);
+        json.put("modifiedDate", modifiedDate);
+        json.put("title", title);
+        json.put("url", url);
+        json.put("visible", visible);
+        json.put("container", container);
+        json.put("restype", "");
+        return json;
+    }
+
     public static class File extends Resource implements LayoutItemType {
         private final String type;
 
@@ -91,6 +107,14 @@ public abstract class Resource implements Serializable {
         public @LayoutRes int getLayoutId() {
             return R.layout.item_file;
         }
+
+        @Override
+        public JSONObject toJSONObject() throws JSONException {
+            JSONObject json = super.toJSONObject();
+            json.put("type", type);
+            json.put("restype", "file");
+            return json;
+        }
     }
 
     public static class Folder extends Resource implements LayoutItemType {
@@ -138,6 +162,14 @@ public abstract class Resource implements Serializable {
         public @LayoutRes int getLayoutId() {
             return R.layout.item_dir;
         }
+
+        @Override
+        public JSONObject toJSONObject() throws JSONException {
+            JSONObject json = super.toJSONObject();
+            json.put("children", UtilsJson.collectionToJson(children));
+            json.put("restype", "dir");
+            return json;
+        }
     }
 }
 

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Semester.java

@@ -1,11 +1,13 @@
 package de.sebse.fuplanner.services.kvv.types;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 import androidx.annotation.Nullable;
 import de.sebse.fuplanner.tools.Regex;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Semester implements Serializable {
+public class Semester implements UtilsJson.JsonConvertible {
     public static final int SEM_WS = 1;
     public static final int SEM_SS = 2;
     private int type;
@@ -17,25 +19,17 @@ public class Semester implements Serializable {
     }
 
     public Semester(String semester_string) throws NoSuchFieldException {
-        /*Semester sem = null;
-            if (semester != null) {
-                sem = new Semester(semester)
-                semester = semester.replace("SS", "S");
-                semester = semester.replaceAll("[0-9]{2}([0-9]{2})", "$1");
-            }*/
-
-
-        /*String s1type = Regex.regex("^(S|WS) ", a);
-        int s1year = Integer.parseInt(Regex.regex("^(S|WS) ([0-9]{2})", a, 2));
-        String s2type = Regex.regex("^(S|WS) ", b);
-        int s2year = Integer.parseInt(Regex.regex("^(S|WS) ([0-9]{2})", b, 2));*/
-
         String type = Regex.regex("^(SS|WS) ", semester_string);
         String year = Regex.regex("^(SS|WS) ([0-9]{2})", semester_string, 2);
         this.type = type.equals("SS") ? SEM_SS : SEM_WS;
         this.year = Integer.parseInt(year);
     }
 
+    public Semester(JSONObject json) throws JSONException {
+        this.type = json.getInt("type");
+        this.year = json.getInt("year");
+    }
+
     public int getType() {
         return type;
     }
@@ -52,4 +46,12 @@ public class Semester implements Serializable {
         }
         return false;
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("type", type);
+        json.put("year", year);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/SortedListModule.java

@@ -1,5 +1,8 @@
 package de.sebse.fuplanner.services.kvv.types;
 
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import androidx.annotation.Nullable;
 import de.sebse.fuplanner.tools.SortedList;
 

app/src/main/java/de/sebse/fuplanner/tools/SortedList.java

@@ -3,12 +3,11 @@ package de.sebse.fuplanner.tools;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
 
-public abstract class SortedList<T, I, F> implements Iterable<T>, Serializable {
+public abstract class SortedList<T, I, F> implements Iterable<T> {
 
     private final ArrayList<T> internalList = new ArrayList<>();
 

app/src/main/java/de/sebse/fuplanner/tools/UtilsJson.java

@@ -0,0 +1,109 @@
+package de.sebse.fuplanner.tools;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+public class UtilsJson {
+    public static JSONArray collectionToJson(@Nullable HashSet<String> coll) {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (String e: coll) {
+            arr.put(e);
+        }
+        return arr;
+    }
+
+    public static <E extends JsonConvertible> JSONArray collectionToJson(@Nullable Collection<E> coll) throws JSONException {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (E e: coll) {
+            arr.put(e.toJSONObject());
+        }
+        return arr;
+    }
+
+    public static JSONArray collectionToJson(@Nullable ArrayList<String> coll) throws JSONException {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (String e: coll) {
+            arr.put(e);
+        }
+        return arr;
+    }
+
+    public static <A extends JsonConvertible> JSONArray collectionToJson(@Nullable SortedList<A, ?, ?> coll) throws JSONException {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (A e: coll) {
+            arr.put(e.toJSONObject());
+        }
+        return arr;
+    }
+
+    public static <T> Iterator<T> jsonArrayToIterator(JSONArray array, GetInterface<T> func) {
+        return new Iterator<T>() {
+            int size = array == null ? 0 : array.length();
+            int pos = 0;
+            @Override
+            public boolean hasNext() {
+                return pos < size;
+            }
+
+            @Override
+            public T next() {
+                try {
+                    return func.get(array, pos++);
+                } catch (JSONException e) {
+                    e.printStackTrace();
+                    return null;
+                }
+            }
+        };
+    }
+
+    @FunctionalInterface
+    private interface GetInterface<T> {
+        T get(JSONArray array, int index) throws JSONException;
+    }
+
+    public static JsonIterable<JSONObject> jsonArrayToIterableObject(JSONArray array) {
+        return new JsonIterable<>(array, JSONArray::getJSONObject);
+    }
+
+    public static JsonIterable<String> jsonArrayToIterableString(JSONArray array) {
+        return new JsonIterable<>(array, JSONArray::getString);
+    }
+
+    public static class JsonIterable<T> implements Iterable<T> {
+        private JSONArray array;
+        private GetInterface<T> getInterface;
+
+        JsonIterable(JSONArray array, GetInterface<T> getInterface) {
+            this.array = array;
+            this.getInterface = getInterface;
+        }
+        @NonNull
+        @Override
+        public Iterator<T> iterator() {
+            return UtilsJson.jsonArrayToIterator(array, getInterface);
+        }
+    }
+
+    public interface JsonConvertible {
+        JSONObject toJSONObject() throws JSONException;
+    }
+
+}

gradle.properties

@@ -17,12 +17,3 @@ org.gradle.jvmargs=-Xmx1536m
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
-
-systemProp.http.proxyHost=proxy1-3.biotronik.int
-systemProp.http.proxyPort=9090
-systemProp.http.proxyUser=Sebastian%20Seedorf
-systemProp.http.proxyPassword=1111ApoTheke
-systemProp.https.proxyHost=proxy1-3.biotronik.int
-systemProp.https.proxyPort=9090
-systemProp.https.proxyUser=Sebastian%20Seedorf
-systemProp.https.proxyPassword=1111ApoTheke