rewrite favicon fetcher

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

@@ -0,0 +1,120 @@
+package com.commafeed.backend.favicon;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import org.apache.commons.lang.StringUtils;
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.select.Elements;
+
+import com.commafeed.backend.HttpGetter;
+import com.commafeed.backend.HttpGetter.HttpResult;
+import com.commafeed.backend.feed.FeedUtils;
+
+/**
+ * Inspired/Ported from https://github.com/potatolondon/getfavicon
+ * 
+ */
+@Slf4j
+@RequiredArgsConstructor(onConstructor = @__({ @Inject }))
+@Singleton
+public class DefaultFaviconFetcher extends AbstractFaviconFetcher {
+
+	private final HttpGetter getter;
+
+	@Override
+	public byte[] fetch(String url) {
+		if (url == null) {
+			log.debug("url is null");
+			return null;
+		}
+
+		int doubleSlash = url.indexOf("//");
+		if (doubleSlash == -1) {
+			doubleSlash = 0;
+		} else {
+			doubleSlash += 2;
+		}
+		int firstSlash = url.indexOf('/', doubleSlash);
+		if (firstSlash != -1) {
+			url = url.substring(0, firstSlash);
+		}
+
+		byte[] icon = getIconAtRoot(url);
+
+		if (icon == null) {
+			icon = getIconInPage(url);
+		}
+
+		return icon;
+	}
+
+	private byte[] getIconAtRoot(String url) {
+		byte[] bytes = null;
+		String contentType = null;
+
+		try {
+			url = FeedUtils.removeTrailingSlash(url) + "/favicon.ico";
+			log.debug("getting root icon at {}", url);
+			HttpResult result = getter.getBinary(url, TIMEOUT);
+			bytes = result.getContent();
+			contentType = result.getContentType();
+		} catch (Exception e) {
+			log.debug("Failed to retrieve iconAtRoot for url {}: ", url, e);
+		}
+
+		if (!isValidIconResponse(bytes, contentType)) {
+			bytes = null;
+		}
+		return bytes;
+	}
+
+	private byte[] getIconInPage(String url) {
+
+		Document doc = null;
+		try {
+			HttpResult result = getter.getBinary(url, TIMEOUT);
+			doc = Jsoup.parse(new String(result.getContent()), url);
+		} catch (Exception e) {
+			log.debug("Failed to retrieve page to find icon", e);
+			return null;
+		}
+
+		Elements icons = doc.select("link[rel~=(?i)^(shortcut|icon|shortcut icon)$]");
+
+		if (icons.isEmpty()) {
+			log.debug("No icon found in page {}", url);
+			return null;
+		}
+
+		String href = icons.get(0).attr("abs:href");
+		if (StringUtils.isBlank(href)) {
+			log.debug("No icon found in page");
+			return null;
+		}
+
+		log.debug("Found unconfirmed iconInPage at {}", href);
+
+		byte[] bytes = null;
+		String contentType = null;
+		try {
+			HttpResult result = getter.getBinary(href, TIMEOUT);
+			bytes = result.getContent();
+			contentType = result.getContentType();
+		} catch (Exception e) {
+			log.debug("Failed to retrieve icon found in page {}", href, e);
+			return null;
+		}
+
+		if (!isValidIconResponse(bytes, contentType)) {
+			log.debug("Invalid icon found for {}", href);
+			return null;
+		}
+
+		return bytes;
+	}
+}