exception

backend/src/main/java/pdl/backend/ImageDao.java

@@ -16,68 +16,70 @@ import org.springframework.stereotype.Repository;
 @Repository
 public class ImageDao implements Dao<Image> {
 
-    private final Map<Long, Image> images = new HashMap<>();
+	private final Map<Long, Image> images = new HashMap<>();
 
-    public ImageDao() {
-        try {
-            final var folderPath = new ClassPathResource("images");
-            final var folder = folderPath.getFile();
-            getAllImages(folder);
-        } catch (final Exception e) {
-            e.printStackTrace();
-        }
-    }
+	public ImageDao() {
+		try {
+			final var folderPath = new ClassPathResource("images");
+			if (folderPath.exists())
+				throw new ImageResourceMissingException("folderPath is null");
+			final var folder = folderPath.getFile();
+			getAllImages(folder);
+		} catch (final Exception e) {
+			e.printStackTrace();
+		}
+	}
 
-    public void getAllImages(final File folder) {
-        for (final File file : folder.listFiles()) {
-            if (file.isDirectory()) {
-                getAllImages(file);
-            } else {
-                String extension = "";
+	public void getAllImages(final File folder) {
+		for (final File file : folder.listFiles()) {
+			if (file.isDirectory()) {
+				getAllImages(file);
+			} else {
+				String extension = "";
 
-                int i = file.getName().lastIndexOf('.');
-                if (i > 0) {
-                    extension = file.getName().substring(i + 1);
-                }
-                if (!extension.equals("jpg") && !extension.equals("png")) {
-                    continue;
-                }
-                byte[] fileContent;
-                try {
-                    fileContent = Files.readAllBytes(file.toPath());
-                    Image img = new Image(file.getName(), fileContent);
-                    images.put(img.getId(), img);
-                } catch (final IOException e) {
-                    e.printStackTrace();
-                }
-            }
-        }
-    }
+				int i = file.getName().lastIndexOf('.');
+				if (i > 0) {
+					extension = file.getName().substring(i + 1);
+				}
+				if (!extension.equals("jpg") && !extension.equals("png")) {
+					continue;
+				}
+				byte[] fileContent;
+				try {
+					fileContent = Files.readAllBytes(file.toPath());
+					Image img = new Image(file.getName(), fileContent);
+					images.put(img.getId(), img);
+				} catch (final IOException e) {
+					e.printStackTrace();
+				}
+			}
+		}
+	}
 
-    @Override
-    public Optional<Image> retrieve(final long id) {
-        return Optional.ofNullable(images.get(id));
-    }
+	@Override
+	public Optional<Image> retrieve(final long id) {
+		return Optional.ofNullable(images.get(id));
+	}
 
-    @Override
-    public List<Image> retrieveAll() {
-        return new ArrayList<Image>(images.values());
-    }
+	@Override
+	public List<Image> retrieveAll() {
+		return new ArrayList<Image>(images.values());
+	}
 
-    @Override
-    public void create(final Image img) {
-        images.put(img.getId(), img);
-    }
+	@Override
+	public void create(final Image img) {
+		images.put(img.getId(), img);
+	}
 
-    @Override
-    public void update(final Image img, final String[] params) {
-        img.setName(Objects.requireNonNull(params[0], "Name cannot be null"));
+	@Override
+	public void update(final Image img, final String[] params) {
+		img.setName(Objects.requireNonNull(params[0], "Name cannot be null"));
 
-        images.put(img.getId(), img);
-    }
+		images.put(img.getId(), img);
+	}
 
-    @Override
-    public void delete(final Image img) {
-        images.remove(img.getId());
-    }
+	@Override
+	public void delete(final Image img) {
+		images.remove(img.getId());
+	}
 }

backend/src/main/java/pdl/backend/ImageResourceMissingException.java

@@ -0,0 +1,9 @@
+package pdl.backend;
+
+import java.io.FileNotFoundException;
+
+public class ImageResourceMissingException extends FileNotFoundException {
+	public ImageResourceMissingException(String message) {
+		super(message);
+	}
+}