limit upload

src/main/java/cz/kamma/darts/App.java

@@ -17,6 +17,7 @@ import java.util.stream.Collectors;
 public class App {
     private static final Gson GSON = new Gson();
     private static final String DATA_FILE = "stats.json";
+    private static final long MAX_UPLOAD_SIZE = 5 * 1024 * 1024; // 5MB
 
     public static void main(String[] args) throws IOException {
         int port = 8080;
@@ -68,8 +69,35 @@ public class App {
                 return;
             }
 
+            String contentLengthHeader = exchange.getRequestHeaders().getFirst("Content-Length");
+            if (contentLengthHeader != null) {
+                try {
+                    long contentLength = Long.parseLong(contentLengthHeader);
+                    if (contentLength > MAX_UPLOAD_SIZE) {
+                        sendError(exchange, 413, "File too large. Maximum size is 5MB.");
+                        return;
+                    }
+                } catch (NumberFormatException ignored) {
+                }
+            }
+
             InputStream is = exchange.getRequestBody();
-            String body = new String(is.readAllBytes(), StandardCharsets.UTF_8);
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            byte[] buffer = new byte[4096];
+            int bytesRead;
+            long totalRead = 0;
+
+            while ((bytesRead = is.read(buffer)) != -1) {
+                totalRead += bytesRead;
+                if (totalRead > MAX_UPLOAD_SIZE) {
+                    sendError(exchange, 413, "File too large. Maximum size is 5MB.");
+                    return;
+                }
+                baos.write(buffer, 0, bytesRead);
+            }
+
+            byte[] bytes = baos.toByteArray();
+            String body = new String(bytes, StandardCharsets.UTF_8);
             
             try {
                 List<RawGame> rawGames = GSON.fromJson(body, new TypeToken<List<RawGame>>(){}.getType());
@@ -78,15 +106,14 @@ public class App {
                 Files.writeString(Paths.get(DATA_FILE), GSON.toJson(convertedGames));
                 
                 String response = "Upload successful";
-                exchange.sendResponseHeaders(200, response.length());
+                byte[] responseBytes = response.getBytes(StandardCharsets.UTF_8);
-                exchange.getResponseBody().write(response.getBytes());
+                exchange.sendResponseHeaders(200, responseBytes.length);
+                try (OutputStream os = exchange.getResponseBody()) {
+                    os.write(responseBytes);
+                }
             } catch (Exception e) {
                 e.printStackTrace();
-                String response = "Error processing upload: " + e.getMessage();
+                sendError(exchange, 400, "Error processing upload: " + e.getMessage());
-                exchange.sendResponseHeaders(400, response.length());
-                exchange.getResponseBody().write(response.getBytes());
-            } finally {
-                exchange.getResponseBody().close();
             }
         }
 
@@ -139,7 +166,13 @@ public class App {
             return result;
         }
     }
-
+    private static void sendError(HttpExchange exchange, int statusCode, String message) throws IOException {
+        byte[] responseBytes = message.getBytes(StandardCharsets.UTF_8);
+        exchange.sendResponseHeaders(statusCode, responseBytes.length);
+        try (OutputStream os = exchange.getResponseBody()) {
+            os.write(responseBytes);
+        }
+    }
     static class StatsHandler implements HttpHandler {
         @Override
         public void handle(HttpExchange exchange) throws IOException {