perf(SitemapController): reduce number of calls of synchronized print() method by using StringBuilder.

A little related to #1438

Author: php-coder

src/main/java/ru/mystamps/web/feature/site/SitemapController.java

@@ -67,11 +67,7 @@ public void generateSitemapXml(HttpServletResponse response) {
 			writer.print(INDEX_URL_ENTRY);
 
 			for (SitemapInfoDto item : seriesService.findAllForSitemap()) {
-				writer.print("<url><loc>");
-				writer.print(createLocEntry(item));
-				writer.print("</loc><lastmod>");
-				writer.print(createLastModEntry(dateFormatter, item));
-				writer.print("</lastmod></url>\n");
+				writer.print(createUrlEntry(dateFormatter, item));
 			}
 
 			writer.print("</urlset>\n");
@@ -80,6 +76,15 @@ public void generateSitemapXml(HttpServletResponse response) {
 		}
 	}
 
+	private static String createUrlEntry(DateFormat dateFormatter, SitemapInfoDto item) {
+		return new StringBuilder("<url><loc>")
+			.append(createLocEntry(item))
+			.append("</loc><lastmod>")
+			.append(createLastModEntry(dateFormatter, item))
+			.append("</lastmod></url>\n")
+			.toString();
+	}
+	
 	private static String createLocEntry(SitemapInfoDto item) {
 		return SiteUrl.PUBLIC_URL
 			+ SeriesUrl.INFO_SERIES_PAGE.replace("{id}", String.valueOf(item.getId()));