return default content type if invalid instead of crashing

commafeed-server/src/main/java/com/commafeed/backend/favicon/AbstractFaviconFetcher.java

@@ -7,8 +7,6 @@ import org.apache.commons.lang3.StringUtils;
 
 import com.commafeed.backend.model.Feed;
 
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 @Slf4j
@@ -50,11 +48,4 @@ public abstract class AbstractFaviconFetcher {
 
 		return true;
 	}
-
-	@RequiredArgsConstructor
-	@Getter
-	public static class Favicon {
-		private final byte[] icon;
-		private final String mediaType;
-	}
 }

commafeed-server/src/main/java/com/commafeed/backend/favicon/Favicon.java

@@ -0,0 +1,30 @@
+package com.commafeed.backend.favicon;
+
+import jakarta.ws.rs.core.MediaType;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@RequiredArgsConstructor
+@Getter
+@Slf4j
+public class Favicon {
+
+	private static final MediaType DEFAULT_MEDIA_TYPE = MediaType.valueOf("image/x-icon");
+
+	private final byte[] icon;
+	private final MediaType mediaType;
+
+	public Favicon(byte[] icon, String contentType) {
+		this(icon, parseMediaType(contentType));
+	}
+
+	private static MediaType parseMediaType(String contentType) {
+		try {
+			return MediaType.valueOf(contentType);
+		} catch (Exception e) {
+			log.debug("invalid content type '{}' received, returning default value", contentType);
+			return DEFAULT_MEDIA_TYPE;
+		}
+	}
+}

commafeed-server/src/main/java/com/commafeed/backend/service/FeedService.java

@@ -9,7 +9,7 @@ import org.apache.commons.io.IOUtils;
 
 import com.commafeed.backend.dao.FeedDAO;
 import com.commafeed.backend.favicon.AbstractFaviconFetcher;
-import com.commafeed.backend.favicon.AbstractFaviconFetcher.Favicon;
+import com.commafeed.backend.favicon.Favicon;
 import com.commafeed.backend.feed.FeedUtils;
 import com.commafeed.backend.model.Feed;
 

commafeed-server/src/main/java/com/commafeed/frontend/resource/FeedREST.java

@@ -24,7 +24,7 @@ import com.commafeed.backend.cache.CacheService;
 import com.commafeed.backend.dao.FeedCategoryDAO;
 import com.commafeed.backend.dao.FeedEntryStatusDAO;
 import com.commafeed.backend.dao.FeedSubscriptionDAO;
-import com.commafeed.backend.favicon.AbstractFaviconFetcher.Favicon;
+import com.commafeed.backend.favicon.Favicon;
 import com.commafeed.backend.feed.FeedEntryKeyword;
 import com.commafeed.backend.feed.FeedFetcher;
 import com.commafeed.backend.feed.FeedFetcher.FeedFetcherResult;
@@ -364,10 +364,10 @@ public class FeedREST {
 		if (subscription == null) {
 			return Response.status(Status.NOT_FOUND).build();
 		}
+
 		Feed feed = subscription.getFeed();
 		Favicon icon = feedService.fetchFavicon(feed);
-
+		ResponseBuilder builder = Response.ok(icon.getIcon(), icon.getMediaType());
-		ResponseBuilder builder = Response.ok(icon.getIcon(), StringUtils.defaultIfBlank(icon.getMediaType(), "image/x-icon"));
 
 		CacheControl cacheControl = new CacheControl();
 		cacheControl.setMaxAge(2592000);

commafeed-server/src/main/java/com/commafeed/frontend/resource/fever/FeverREST.java

@@ -21,7 +21,7 @@ import com.commafeed.backend.dao.FeedCategoryDAO;
 import com.commafeed.backend.dao.FeedEntryDAO;
 import com.commafeed.backend.dao.FeedEntryStatusDAO;
 import com.commafeed.backend.dao.FeedSubscriptionDAO;
-import com.commafeed.backend.favicon.AbstractFaviconFetcher.Favicon;
+import com.commafeed.backend.favicon.Favicon;
 import com.commafeed.backend.model.Feed;
 import com.commafeed.backend.model.FeedCategory;
 import com.commafeed.backend.model.FeedEntry;