Refactor output streaming for readability

The core loop was put together confusingly; this encapsulates the
process of constructing an OutputStream and reformats some.

airsonic-main/src/main/java/org/airsonic/player/controller/StreamController.java

@@ -208,32 +208,14 @@ public class StreamController {
 
             status = statusService.createStreamStatus(player);
 
-            in = new PlayQueueInputStream(player, status, maxBitRate, preferredTargetFormat, videoTranscodingSettings, transcodingService,
-                    audioScrobblerService, mediaFileService, searchService);
-            OutputStream out = RangeOutputStream.wrap(response.getOutputStream(), range);
-
-            // Enabled SHOUTcast, if requested.
-            boolean isShoutCastRequested = "1".equals(request.getHeader("icy-metadata"));
-            if (isShoutCastRequested && !isSingleFile) {
-                response.setHeader("icy-metaint", "" + ShoutCastOutputStream.META_DATA_INTERVAL);
-                response.setHeader("icy-notice1", "This stream is served using Airsonic");
-                response.setHeader("icy-notice2", "Airsonic - Free media streamer");
-                response.setHeader("icy-name", "Airsonic");
-                response.setHeader("icy-genre", "Mixed");
-                response.setHeader("icy-url", "https://airsonic.github.io/");
-                out = new ShoutCastOutputStream(out, player.getPlayQueue(), settingsService);
-            }
+            in = new PlayQueueInputStream(player, status, maxBitRate, preferredTargetFormat, videoTranscodingSettings,
+                    transcodingService, audioScrobblerService, mediaFileService, searchService);
 
+            try (OutputStream out = makeOutputStream(request, response, range, isSingleFile, player, settingsService)) {
                 final int BUFFER_SIZE = 2048;
                 byte[] buf = new byte[BUFFER_SIZE];
 
-            while (true) {
-
-                // Check if stream has been terminated.
-                if (status.terminated()) {
-                    return;
-                }
-
+                while (!status.terminated()) {
                     if (player.getPlayQueue().getStatus() == PlayQueue.Status.STOPPED) {
                         if (isPodcast || isSingleFile) {
                             break;
@@ -254,6 +236,7 @@ public class StreamController {
                         }
                     }
                 }
+            }
         } catch (IOException e) {
 
             // This happens often and outside of the control of the server, so
@@ -283,6 +266,31 @@ public class StreamController {
         return;
     }
 
+    /**
+     * Construct an appropriate output stream based on the request.
+     * <p>
+     * This is responsible for limiting the output to the given range (if not null) and injecting Shoutcast metadata
+     * into the stream if requested.
+     */
+    private OutputStream makeOutputStream(HttpServletRequest request, HttpServletResponse response, HttpRange range,
+                                          boolean isSingleFile, Player player, SettingsService settingsService)
+            throws IOException {
+        OutputStream out = RangeOutputStream.wrap(response.getOutputStream(), range);
+
+        // Enabled SHOUTcast, if requested.
+        boolean isShoutCastRequested = "1".equals(request.getHeader("icy-metadata"));
+        if (isShoutCastRequested && !isSingleFile) {
+            response.setHeader("icy-metaint", "" + ShoutCastOutputStream.META_DATA_INTERVAL);
+            response.setHeader("icy-notice1", "This stream is served using Airsonic");
+            response.setHeader("icy-notice2", "Airsonic - Free media streamer");
+            response.setHeader("icy-name", "Airsonic");
+            response.setHeader("icy-genre", "Mixed");
+            response.setHeader("icy-url", "https://airsonic.github.io/");
+            out = new ShoutCastOutputStream(out, player.getPlayQueue(), settingsService);
+        }
+        return out;
+    }
+
     private void setContentDuration(HttpServletResponse response, MediaFile file) {
         if (file.getDurationSeconds() != null) {
             response.setHeader("X-Content-Duration", String.format("%.1f", file.getDurationSeconds().doubleValue()));