fix: avoid accidentally deleting new appNamespaceCache of same appid and name with old appNamesppace.

CHANGES.md

@@ -22,5 +22,6 @@ Apollo 2.5.0
 * [optimize: Implement unified permission verification logic and Optimize the implementation of permission verification](https://github.com/apolloconfig/apollo/pull/5456)
 * [CI: Add code and header formatter by spotless plugin](https://github.com/apolloconfig/apollo/pull/5485)
 * [Fix: Operate the AccessKey multiple times within one second](https://github.com/apolloconfig/apollo/pull/5490)
+* [Bugfix: Prevent accidental cache deletion when recreating AppNamespace with the same name and appid](https://github.com/apolloconfig/apollo/issues/5502)
 ------------------
 All issues and pull requests are [here](https://github.com/apolloconfig/apollo/milestone/16?closed=1)

apollo-configservice/src/main/java/com/ctrip/framework/apollo/configservice/service/AppNamespaceServiceWithCache.java

@@ -37,10 +37,7 @@
 import org.springframework.stereotype.Service;
 import org.springframework.util.CollectionUtils;
 
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -261,7 +258,13 @@ private void handleDeletedAppNamespaces(Set<Long> deletedIds) {
       if (deleted == null) {
         continue;
       }
-      appNamespaceCache.remove(assembleAppNamespaceKey(deleted));
+
+      String appNamespaceKey = assembleAppNamespaceKey(deleted);
+      AppNamespace appNamespace = appNamespaceCache.get(appNamespaceKey);
+      if (appNamespace != null && Objects.equals(appNamespace.getId(), deletedId)) {
+        appNamespaceCache.remove(appNamespaceKey);
+      }
+
       if (deleted.isPublic()) {
         AppNamespace publicAppNamespace = publicAppNamespaceCache.get(deleted.getName());
         // in case there is some dirty data, e.g. public namespace deleted in some app and now

apollo-configservice/src/test/java/com/ctrip/framework/apollo/configservice/service/AppNamespaceServiceWithCacheTest.java

@@ -38,6 +38,7 @@
 
 import static org.awaitility.Awaitility.await;
 import static org.junit.Assert.*;
+import static org.mockito.ArgumentMatchers.anyList;
 import static org.mockito.Mockito.when;
 
 /**
@@ -311,4 +312,54 @@ private AppNamespace assembleAppNamespace(long id, String appId, String name, bo
     appNamespace.setDataChangeLastModifiedTime(new Date());
     return appNamespace;
   }
+
+  /**
+   * fix issue #5502
+   */
+  @Test
+  public void doubleCheckForAppNamespaceCache() throws Exception {
+    String appId = "app1";
+    String namespaceName = "name1";
+
+    AppNamespace oldNs = assembleAppNamespace(1, appId, namespaceName, false);
+
+    AppNamespace newNs = assembleAppNamespace(2, appId, namespaceName, false);
+
+    when(appNamespaceRepository.findFirst500ByIdGreaterThanOrderByIdAsc(0))
+        .thenReturn(Lists.newArrayList(oldNs));
+
+    invokePrivateMethod("scanNewAppNamespaces");
+
+    AppNamespace cached =
+        appNamespaceServiceWithCache.findByAppIdAndNamespace(appId, namespaceName);
+    assertNotNull(cached);
+    assertEquals(1, cached.getId());
+
+    when(appNamespaceRepository.findFirst500ByIdGreaterThanOrderByIdAsc(1))
+        .thenReturn(Lists.newArrayList(newNs));
+
+    invokePrivateMethod("scanNewAppNamespaces");
+
+    cached = appNamespaceServiceWithCache.findByAppIdAndNamespace(appId, namespaceName);
+    assertNotNull(cached);
+    assertEquals(2, cached.getId());
+
+    when(appNamespaceRepository.findAllById(anyList()))
+        .thenAnswer(invocation -> Lists.newArrayList(newNs));
+
+    invokePrivateMethod("updateAndDeleteCache");
+
+    cached = appNamespaceServiceWithCache.findByAppIdAndNamespace(appId, namespaceName);
+
+    assertNotNull("new cache is accidentally deleted", cached);
+    assertEquals(2, cached.getId());
+  }
+
+  private void invokePrivateMethod(String methodName) throws Exception {
+    java.lang.reflect.Method method =
+        AppNamespaceServiceWithCache.class.getDeclaredMethod(methodName);
+    method.setAccessible(true);
+    method.invoke(appNamespaceServiceWithCache);
+  }
+
 }