added lab13 ex1

src/lab13_proxy/ex1/Image.java

@@ -0,0 +1,27 @@
+package lab13_proxy.ex1;
+
+public class Image {
+    protected final String path;
+    protected final String resolution;
+    protected boolean loaded = false;
+
+    public Image(String path, String resolution) {
+        this.path = path;
+        this.resolution = resolution;
+    }
+
+    public void load() {
+        if (!loaded) {
+            System.out.println("Image " + path + " is loaded in " + resolution + " resolution");
+            loaded = true;
+        }
+    }
+
+    public boolean isLoaded() {
+        return loaded;
+    }
+
+    public void showImage(User user) {
+        System.out.println("Image " + path + " is shown in " + resolution + " resolution for user " + user.getName());
+    }
+}

src/lab13_proxy/ex1/ImageProxy.java

@@ -0,0 +1,24 @@
+package lab13_proxy.ex1;
+
+public class ImageProxy extends Image {
+    private final Image lowResImage;
+    private final Image highResImage;
+
+    public ImageProxy(String path) {
+        super(path, "high");
+        lowResImage = new Image(path, "low");
+        highResImage = new Image(path, "high");
+    }
+
+    public void showImage(User user) {
+        System.out.println(user.getName() + " selects preview image " + path + " and wants to see its full resolution.");
+        if (RegistrationService.isRegistered(user)) {
+            highResImage.load();
+            highResImage.showImage(user);
+        } else {
+            System.out.println("User " + user.getName() + " is not registered. Showing preview image in low resolution");
+            lowResImage.load();
+            lowResImage.showImage(user);
+        }
+    }
+}

src/lab13_proxy/ex1/Main.java

@@ -0,0 +1,19 @@
+package lab13_proxy.ex1;
+
+public class Main {
+    public static void main(String[] args) {
+        User jean = new User("Jean");
+        User paul = new User("Paul");
+        User pierre = new User("Pierre");
+
+        RegistrationService.register(paul);
+
+        Image highResolutionImage1 = new ImageProxy("sample/veryHighResPhoto1.jpeg");
+        Image highResolutionImage2 = new ImageProxy("sample/veryHighResPhoto2.jpeg");
+        Image highResolutionImage3 = new ImageProxy("sample/veryHighResPhoto3.jpeg");
+
+        highResolutionImage1.showImage(jean);
+        highResolutionImage2.showImage(paul);
+        highResolutionImage3.showImage(pierre);
+    }
+}

src/lab13_proxy/ex1/RegistrationService.java

@@ -0,0 +1,15 @@
+package lab13_proxy.ex1;
+
+import java.util.ArrayList;
+
+public class RegistrationService {
+    private static final ArrayList<User> users = new ArrayList<>();
+    public static void register(User user) {
+        System.out.println(user.getName() + " is now registered");
+        users.add(user);
+    }
+
+    public static boolean isRegistered(User user) {
+        return users.contains(user);
+    }
+}

src/lab13_proxy/ex1/User.java

@@ -0,0 +1,13 @@
+package lab13_proxy.ex1;
+
+public class User {
+    private final String name;
+
+    public User(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+}