Refactor ShardingSphereStatisticsFactory

mode/core/src/main/java/org/apache/shardingsphere/mode/metadata/ShardingSphereStatisticsFactory.java

@@ -53,21 +53,14 @@ public static ShardingSphereStatistics create(final MetaDataPersistService persi
         if (metaData.getAllDatabases().isEmpty()) {
             return new ShardingSphereStatistics();
         }
-        Optional<DialectStatisticsAppender> dialectStatisticsAppender = DatabaseTypedSPILoader.findService(DialectStatisticsAppender.class, getDatabaseType(metaData));
-        if (!dialectStatisticsAppender.isPresent()) {
-            return new ShardingSphereStatistics();
-        }
+
         ShardingSphereStatistics loadedStatistics = persistService.getShardingSphereDataPersistService().load(metaData).orElse(new ShardingSphereStatistics());
         Collection<ShardingSphereDatabase> unloadedDatabases = metaData.getAllDatabases().stream().filter(each -> !loadedStatistics.containsDatabase(each.getName())).collect(Collectors.toList());
-        return create(dialectStatisticsAppender.get(), unloadedDatabases, loadedStatistics);
-    }
-
-    private static ShardingSphereStatistics create(final DialectStatisticsAppender dialectStatisticsAppender,
-                                                   final Collection<ShardingSphereDatabase> unloadedDatabases, final ShardingSphereStatistics loadedStatistics) {
         ShardingSphereStatistics result = new ShardingSphereStatistics();
+        Optional<DialectStatisticsAppender> dialectStatisticsAppender = DatabaseTypedSPILoader.findService(DialectStatisticsAppender.class, getDatabaseType(metaData));
         for (ShardingSphereDatabase each : unloadedDatabases) {
             ShardingSphereDatabaseData databaseData = new ShardingSphereDefaultStatisticsBuilder().build(each);
-            dialectStatisticsAppender.append(databaseData, each);
+            dialectStatisticsAppender.ifPresent(optional -> optional.append(databaseData, each));
             if (!databaseData.getSchemaData().isEmpty()) {
                 result.putDatabase(each.getName(), databaseData);
             }

mode/core/src/test/java/org/apache/shardingsphere/mode/metadata/MetaDataContextsTest.java

@@ -26,18 +26,24 @@
 import org.junit.jupiter.api.Test;
 
 import java.util.Collections;
+import java.util.Optional;
 import java.util.Properties;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 class MetaDataContextsTest {
 
     @Test
     void assertGetDefaultMetaData() {
         ShardingSphereDatabase database = new ShardingSphereDatabase("foo_db", TypedSPILoader.getService(DatabaseType.class, "FIXTURE"), mock(), mock(), Collections.emptyList());
         ShardingSphereMetaData metaData = new ShardingSphereMetaData(Collections.singleton(database), mock(), mock(), new ConfigurationProperties(new Properties()));
-        assertThat(new MetaDataContexts(metaData, ShardingSphereStatisticsFactory.create(mock(MetaDataPersistService.class), metaData)).getMetaData().getDatabase("foo_db"), is(database));
+        MetaDataPersistService persistService = mock(MetaDataPersistService.class, RETURNS_DEEP_STUBS);
+        when(persistService.getShardingSphereDataPersistService().load(any())).thenReturn(Optional.empty());
+        assertThat(new MetaDataContexts(metaData, ShardingSphereStatisticsFactory.create(persistService, metaData)).getMetaData().getDatabase("foo_db"), is(database));
     }
 }