Add processing of Accept header to AudioServlet (#2960)

Signed-off-by: Jan N. Klug <github@klug.nrw>

bundles/org.openhab.core.audio/src/main/java/org/openhab/core/audio/internal/AudioServlet.java

@@ -18,10 +18,12 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -53,6 +55,8 @@ public class AudioServlet extends OpenHABServlet implements AudioHTTPServer {
 
     private static final long serialVersionUID = -3364664035854567854L;
 
+    private static final List<String> WAV_MIME_TYPES = List.of("audio/wav", "audio/x-wav", "audio/vnd.wave");
+
     private static final String SERVLET_NAME = "/audio";
 
     private final Map<String, AudioStream> oneTimeStreams = new ConcurrentHashMap<>();
@@ -90,8 +94,8 @@ public class AudioServlet extends OpenHABServlet implements AudioHTTPServer {
         }
     }
 
-    private @Nullable InputStream prepareInputStream(final String streamId, final HttpServletResponse resp)
+    private @Nullable InputStream prepareInputStream(final String streamId, final HttpServletResponse resp,
-            throws AudioException {
+            List<String> acceptedMimeTypes) throws AudioException {
         final AudioStream stream;
         final boolean multiAccess;
         if (oneTimeStreams.containsKey(streamId)) {
@@ -111,7 +115,7 @@ public class AudioServlet extends OpenHABServlet implements AudioHTTPServer {
         if (AudioFormat.CODEC_MP3.equals(stream.getFormat().getCodec())) {
             mimeType = "audio/mpeg";
         } else if (AudioFormat.CONTAINER_WAVE.equals(stream.getFormat().getContainer())) {
-            mimeType = "audio/wav";
+            mimeType = WAV_MIME_TYPES.stream().filter(acceptedMimeTypes::contains).findFirst().orElse("audio/wav");
         } else if (AudioFormat.CONTAINER_OGG.equals(stream.getFormat().getContainer())) {
             mimeType = "audio/ogg";
         } else {
@@ -158,7 +162,10 @@ public class AudioServlet extends OpenHABServlet implements AudioHTTPServer {
 
         final String streamId = substringBefore(substringAfterLast(requestURI, "/"), ".");
 
-        try (final InputStream stream = prepareInputStream(streamId, resp)) {
+        List<String> acceptedMimeTypes = Stream.of(Objects.requireNonNullElse(req.getHeader("Accept"), "").split(","))
+                .map(String::trim).collect(Collectors.toList());
+
+        try (final InputStream stream = prepareInputStream(streamId, resp, acceptedMimeTypes)) {
             if (stream == null) {
                 logger.debug("Received request for invalid stream id at {}", requestURI);
                 resp.sendError(HttpServletResponse.SC_NOT_FOUND);

bundles/org.openhab.core.audio/src/test/java/org/openhab/core/audio/internal/AbstractAudioServletTest.java

@@ -97,6 +97,11 @@ public abstract class AbstractAudioServletTest extends JavaTest {
         return getHttpRequest(url).send();
     }
 
+    protected ContentResponse getHttpResponseWithAccept(AudioStream audioStream, String acceptHeader) throws Exception {
+        String url = serveStream(audioStream);
+        return getHttpRequest(url).header("Accept", acceptHeader).send();
+    }
+
     protected String serveStream(AudioStream stream) throws Exception {
         return serveStream(stream, null);
     }

bundles/org.openhab.core.audio/src/test/java/org/openhab/core/audio/internal/AudioServletTest.java

@@ -62,7 +62,7 @@ public class AudioServletTest extends AbstractAudioServletTest {
     }
 
     @Test
-    public void audioServletProcessesStreamFromWavFile() throws Exception {
+    public void audioServletProcessesStreamFromWavFileWithoutAcceptHeader() throws Exception {
         try (BundledSoundFileHandler fileHandler = new BundledSoundFileHandler()) {
             AudioStream audioStream = new FileAudioStream(new File(fileHandler.wavFilePath()));
 
@@ -74,6 +74,18 @@ public class AudioServletTest extends AbstractAudioServletTest {
         }
     }
 
+    @Test
+    public void audioServletProcessesStreamFromWavFileWithAcceptHeader() throws Exception {
+        try (BundledSoundFileHandler fileHandler = new BundledSoundFileHandler()) {
+            AudioStream audioStream = new FileAudioStream(new File(fileHandler.wavFilePath()));
+
+            ContentResponse response = getHttpResponseWithAccept(audioStream, "audio/invalid, audio/x-wav");
+
+            assertThat("The response status was not as expected", response.getStatus(), is(HttpStatus.OK_200));
+            assertThat("The response media type was not as expected", response.getMediaType(), is("audio/x-wav"));
+        }
+    }
+
     @Test
     public void audioServletProcessesStreamFromOggContainer() throws Exception {
         AudioStream audioStream = getByteArrayAudioStream(testByteArray, AudioFormat.CONTAINER_OGG,