fix: handle live stream reuse when already streaming and improve error handling

sample/src/main/java/com/dji/sample/manage/service/impl/LiveStreamServiceImpl.java

@@ -37,6 +37,8 @@ import java.util.stream.Collectors;
 @Slf4j
 public class LiveStreamServiceImpl implements ILiveStreamService {
 
+    private static final int LIVE_ALREADY_STREAMING_CODE = 513003;
+
     @Autowired
     private ICapacityCameraService capacityCameraService;
 
@@ -137,8 +139,14 @@ public class LiveStreamServiceImpl implements ILiveStreamService {
                         .setVideoId(liveParam.getVideoId())
                         .setVideoQuality(liveParam.getVideoQuality()));
 
-        if (!response.getData().getResult().isSuccess()) {
-            return HttpResultResponse.error(response.getData().getResult());
+        boolean isStartPushSuccess = response.getData().getResult().isSuccess();
+        if (!isStartPushSuccess) {
+            HttpResultResponse errorResponse = HttpResultResponse.error(response.getData().getResult());
+            // 复用场景：设备已在直播时，不应阻断新观看者会话注册
+            if (errorResponse.getCode() != LIVE_ALREADY_STREAMING_CODE) {
+                return errorResponse;
+            }
+            log.info("Live stream already started on device, reuse existing stream. videoId={}", liveParam.getVideoId());
         }
 
         LiveDTO live = new LiveDTO();
@@ -161,7 +169,15 @@ public class LiveStreamServiceImpl implements ILiveStreamService {
                         .toString());
                 break;
             case RTSP:
+                if (StringUtils.hasText(response.getData().getOutput())) {
                     live.setUrl(response.getData().getOutput());
+                } else {
+                    // RTSP 在“已在直播”且无 output 时无法构造可用地址，返回原始错误
+                    if (!isStartPushSuccess) {
+                        return HttpResultResponse.error(response.getData().getResult());
+                    }
+                    live.setUrl(url.toString());
+                }
                 break;
             case WHIP:
                 live.setUrl(url.toString().replace("whip", "whep"));