updaterat i StaticFileHandler och skapat CacheFilter

# Conflicts:
#	src/main/java/org/example/StaticFileHandler.java

Author: Boppler12

src/main/java/org/example/CacheFilter.java

@@ -0,0 +1,23 @@
+package org.example;
+
+import java.io.IOException;
+
+public class CacheFilter {
+    private final FileCache cache = new FileCache();
+    
+    public byte[] getOrFetch(String uri, FileProvider provider) throws IOException {
+        if (cache.contains(uri)) {
+            System.out.println("✓ Cache hit for: " + uri);
+            return cache.get(uri);
+        }
+        System.out.println("✗ Cache miss for: " + uri);
+        byte[] fileBytes = provider.fetch(uri);
+        cache.put(uri, fileBytes);
+        return fileBytes;
+    }
+    
+    @FunctionalInterface
+    public interface FileProvider {
+        byte[] fetch(String uri) throws IOException;
+    }
+}