🗃️ Prepare persistence layer

src/data/Loadable.java

@@ -1,4 +1,9 @@
 package data;
 
+import viewmodel.PromotionVM;
+
+import java.io.IOException;
+
 public interface Loadable {
+    PromotionVM load() throws IOException, ClassNotFoundException;
 }

src/data/Loader.java

@@ -0,0 +1,17 @@
+package data;
+
+import model.Promotion;
+import viewmodel.PromotionVM;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+
+public class Loader implements Loadable {
+    @Override
+    public PromotionVM load() throws IOException, ClassNotFoundException {
+        try(ObjectInputStream ois = new ObjectInputStream(new FileInputStream("save.bin"))) {
+            return new PromotionVM(ois.readObject());
+        }
+    }
+}

src/data/Savable.java

@@ -0,0 +1,9 @@
+package data;
+
+import viewmodel.PromotionVM;
+
+import java.io.IOException;
+
+public interface Savable {
+    void save(PromotionVM VM) throws IOException;
+}

src/data/Saver.java

@@ -0,0 +1,16 @@
+package data;
+
+import viewmodel.PromotionVM;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+
+public class Saver implements Savable {
+    @Override
+    public void save(PromotionVM VM) throws IOException {
+        try(ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("save.bin"))) {
+            oos.writeObject(VM.getModel());
+        }
+    }
+}

src/data/Stub.java

@@ -0,0 +1,15 @@
+package data;
+
+import viewmodel.PromotionVM;
+
+public class Stub implements Loadable {
+
+    @Override
+    public PromotionVM load(){
+        PromotionVM VM = new PromotionVM();
+
+        //... add studentVMs
+
+        return VM;
+    }
+}

src/launcher/Launcher.java

@@ -1,22 +1,39 @@
 package launcher;
 
+import data.Loadable;
+import data.Loader;
+import data.Saver;
+import data.Stub;
 import javafx.application.Application;
-import javafx.fxml.FXML;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
 import javafx.scene.Scene;
 import javafx.stage.Stage;
 import view.MainWindow;
+import viewmodel.PromotionVM;
+
+import java.io.IOException;
 
 public class Launcher extends Application {
 
-    //vm
+    private PromotionVM VM = null;
 
     @Override
     public void start(Stage primaryStage) throws Exception {
-        //load
+        Loadable loader;
+
+        try {
+            loader = new Loader();
+            VM = loader.load();
+        } catch (IOException | ClassNotFoundException __) {
+            System.err.println("could not load...");
+            loader = new Stub();
+            VM = loader.load();
+        }
+        if (VM == null) VM = new PromotionVM();
+
         FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/fxml/MainWindow.fxml"));
-        fxmlLoader.setController(new MainWindow(/*VM goes here*/));
+        fxmlLoader.setController(new MainWindow(VM));
         Parent root = fxmlLoader.load();
         Scene scene = new Scene(root);
         primaryStage.setScene(scene);
@@ -25,7 +42,12 @@ public class Launcher extends Application {
 
     @Override
     public void stop() throws Exception {
-        //save
+        try {
+            new Saver().save(VM);
+        } catch (IOException __) {
+            System.err.println("couls not save...");
+        }
+
         super.stop();
     }
 }

src/view/MainWindow.java

@@ -1,4 +1,11 @@
 package view;
 
+import viewmodel.PromotionVM;
+
 public class MainWindow {
+    private final PromotionVM VM;
+
+    public MainWindow(PromotionVM VM) {
+        this.VM = VM;
+    }
 }

src/viewmodel/PromotionVM.java

@@ -0,0 +1,20 @@
+package viewmodel;
+
+import model.Promotion;
+
+public class PromotionVM {
+
+    private Promotion model;
+
+    public PromotionVM(Object o) {
+
+    }
+
+    public PromotionVM() {
+
+    }
+
+    public Promotion getModel() {
+        return model;
+    }
+}