return the correct media type for favicons (fix #736)

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

@@ -3,6 +3,8 @@ package com.commafeed.backend.favicon;
 import java.util.Arrays;
 import java.util.List;
 
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import org.apache.commons.lang3.StringUtils;
@@ -18,7 +20,7 @@ public abstract class AbstractFaviconFetcher {
 
 	protected static int TIMEOUT = 4000;
 
-	public abstract byte[] fetch(Feed feed);
+	public abstract Favicon fetch(Feed feed);
 
 	protected boolean isValidIconResponse(byte[] content, String contentType) {
 		if (content == null) {
@@ -48,4 +50,11 @@ public abstract class AbstractFaviconFetcher {
 
 		return true;
 	}
+
+	@RequiredArgsConstructor
+	@Getter
+	public static class Favicon {
+		private final byte[] icon;
+		private final String mediaType;
+	}
 }

src/main/java/com/commafeed/backend/favicon/DefaultFaviconFetcher.java

@@ -28,15 +28,15 @@ public class DefaultFaviconFetcher extends AbstractFaviconFetcher {
 	private final HttpGetter getter;
 
 	@Override
-	public byte[] fetch(Feed feed) {
+	public Favicon fetch(Feed feed) {
-		byte[] icon = fetch(feed.getLink());
+		Favicon icon = fetch(feed.getLink());
 		if (icon == null) {
 			icon = fetch(feed.getUrl());
 		}
 		return icon;
 	}
 
-	private byte[] fetch(String url) {
+	private Favicon fetch(String url) {
 		if (url == null) {
 			log.debug("url is null");
 			return null;
@@ -53,7 +53,7 @@ public class DefaultFaviconFetcher extends AbstractFaviconFetcher {
 			url = url.substring(0, firstSlash);
 		}
 
-		byte[] icon = getIconAtRoot(url);
+		Favicon icon = getIconAtRoot(url);
 
 		if (icon == null) {
 			icon = getIconInPage(url);
@@ -62,7 +62,7 @@ public class DefaultFaviconFetcher extends AbstractFaviconFetcher {
 		return icon;
 	}
 
-	private byte[] getIconAtRoot(String url) {
+	private Favicon getIconAtRoot(String url) {
 		byte[] bytes = null;
 		String contentType = null;
 
@@ -78,12 +78,12 @@ public class DefaultFaviconFetcher extends AbstractFaviconFetcher {
 		}
 
 		if (!isValidIconResponse(bytes, contentType)) {
-			bytes = null;
+			return null;
 		}
-		return bytes;
+		return new Favicon(bytes, contentType);
 	}
 
-	private byte[] getIconInPage(String url) {
+	private Favicon getIconInPage(String url) {
 
 		Document doc = null;
 		try {
@@ -127,6 +127,6 @@ public class DefaultFaviconFetcher extends AbstractFaviconFetcher {
 			return null;
 		}
 
-		return bytes;
+		return new Favicon(bytes, contentType);
 	}
 }

src/main/java/com/commafeed/backend/favicon/FacebookFaviconFetcher.java

@@ -26,7 +26,7 @@ public class FacebookFaviconFetcher extends AbstractFaviconFetcher {
 	private final HttpGetter getter;
 
 	@Override
-	public byte[] fetch(Feed feed) {
+	public Favicon fetch(Feed feed) {
 		String url = feed.getUrl();
 
 		if (!url.toLowerCase().contains("www.facebook.com")) {
@@ -54,9 +54,9 @@ public class FacebookFaviconFetcher extends AbstractFaviconFetcher {
 		}
 
 		if (!isValidIconResponse(bytes, contentType)) {
-			bytes = null;
+			return null;
 		}
-		return bytes;
+		return new Favicon(bytes, contentType);
 	}
 
 	private String extractUserName(String url) {

src/main/java/com/commafeed/backend/favicon/YoutubeFaviconFetcher.java

@@ -36,7 +36,7 @@ public class YoutubeFaviconFetcher extends AbstractFaviconFetcher {
 	private final CommaFeedConfiguration config;
 
 	@Override
-	public byte[] fetch(Feed feed) {
+	public Favicon fetch(Feed feed) {
 		String url = feed.getUrl();
 
 		if (!url.toLowerCase().contains("youtube.com/feeds/videos.xml")) {
@@ -94,8 +94,8 @@ public class YoutubeFaviconFetcher extends AbstractFaviconFetcher {
 		}
 
 		if (!isValidIconResponse(bytes, contentType)) {
-			bytes = null;
+			return null;
 		}
-		return bytes;
+		return new Favicon(bytes, contentType);
 	}
 }

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

@@ -12,6 +12,7 @@ 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.feed.FeedUtils;
 import com.commafeed.backend.model.Feed;
 
@@ -21,7 +22,7 @@ public class FeedService {
 	private final FeedDAO feedDAO;
 	private final Set<AbstractFaviconFetcher> faviconFetchers;
 
-	private byte[] defaultFavicon;
+	private Favicon defaultFavicon;
 
 	@Inject
 	public FeedService(FeedDAO feedDAO, Set<AbstractFaviconFetcher> faviconFetchers) {
@@ -29,7 +30,7 @@ public class FeedService {
 		this.faviconFetchers = faviconFetchers;
 
 		try {
-			defaultFavicon = IOUtils.toByteArray(getClass().getResource("/images/default_favicon.gif"));
+			defaultFavicon = new Favicon(IOUtils.toByteArray(getClass().getResource("/images/default_favicon.gif")), "image/gif");
 		} catch (IOException e) {
 			throw new RuntimeException("could not load default favicon", e);
 		}
@@ -49,9 +50,9 @@ public class FeedService {
 		return feed;
 	}
 
-	public byte[] fetchFavicon(Feed feed) {
+	public Favicon fetchFavicon(Feed feed) {
 
-		byte[] icon = null;
+		Favicon icon = null;
 		for (AbstractFaviconFetcher faviconFetcher : faviconFetchers) {
 			icon = faviconFetcher.fetch(feed);
 			if (icon != null) {

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

@@ -12,6 +12,7 @@ import java.util.Comparator;
 import java.util.Date;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 import javax.inject.Inject;
@@ -45,6 +46,7 @@ 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.feed.FeedEntryKeyword;
 import com.commafeed.backend.feed.FeedFetcher;
 import com.commafeed.backend.feed.FeedQueues;
@@ -339,9 +341,9 @@ public class FeedREST {
 			return Response.status(Status.NOT_FOUND).build();
 		}
 		Feed feed = subscription.getFeed();
-		byte[] icon = feedService.fetchFavicon(feed);
+		Favicon icon = feedService.fetchFavicon(feed);
 
-		ResponseBuilder builder = Response.ok(icon, "image/x-icon");
+		ResponseBuilder builder = Response.ok(icon.getIcon(), Optional.ofNullable(icon.getMediaType()).orElse("image/x-icon"));
 
 		CacheControl cacheControl = new CacheControl();
 		cacheControl.setMaxAge(2592000);