补齐连接反复断开和缓存失败重试边界

src/main/java/com/lion/lionwebsite/Service/RemoteService.java

@@ -386,6 +386,13 @@ public class RemoteService {
         } finally {
             monitorSocket = null;
             monitoring.set(false);
+            // A connection may flap while the previous monitor is still exiting.
+            if (!stopping && isDead()) {
+                try { networkGroup.next().schedule(this::startMonitor, 5, TimeUnit.SECONDS); }
+                catch (java.util.concurrent.RejectedExecutionException e) {
+                    if (!stopping) log.warn("安排节点监听重试失败", e);
+                }
+            }
         }
     }
 

src/test/java/com/lion/lionwebsite/Util/ImageFileCacheTest.java

@@ -25,6 +25,9 @@ class ImageFileCacheTest {
         assertThrows(Exception.class, () -> ImageFileCache.get(cache, "1", () -> root.resolve("missing.gif").toUri().toString()));
         assertNull(ImageFileCache.find(cache, "1"));
         try (var files = Files.list(cache)) { assertEquals(0, files.count()); }
+        Path source = root.resolve("retry.gif");
+        Files.writeString(source, "GIF89a retry");
+        assertNotNull(ImageFileCache.get(cache, "1", () -> source.toUri().toString()));
     }
 
     @Test void concurrentCallersShareTheSameOperation() throws Exception {