fix sonar

server/src/main/java/org/apache/iotdb/db/engine/flush/VmMergeUtils.java

@@ -136,10 +136,7 @@ public class VmMergeUtils {
     for (RestorableTsFileIOWriter vmWriter : vmWriters) {
       TsFileSequenceReader reader = buildReaderFromVmWriter(vmWriter,
           writer, tsFileSequenceReaderMap, storageGroup);
-      if (reader == null) {
-        continue;
-      }
-      if (!vmWriter.getMetadatasForQuery().containsKey(deviceId)) {
+      if (reader == null || !vmWriter.getMetadatasForQuery().containsKey(deviceId)) {
         continue;
       }
       List<ChunkMetadata> chunkMetadataList = vmWriter.getMetadatasForQuery()

server/src/main/java/org/apache/iotdb/db/engine/storagegroup/StorageGroupProcessor.java

@@ -594,7 +594,7 @@ public class StorageGroupProcessor {
     }
     vmTsFileResourceMap.values()
         .forEach(tsFileResources -> tsFileResources
-            .forEach((subVmTsFileResources) -> subVmTsFileResources.sort(this::compareVMFileName)));
+            .forEach(subVmTsFileResources -> subVmTsFileResources.sort(this::compareVMFileName)));
     return vmTsFileResourceMap;
   }
 
@@ -632,7 +632,7 @@ public class StorageGroupProcessor {
         writer = pair.left;
         vmWriters = pair.right;
         vmWriters.forEach(
-            (subVmWriters) -> subVmWriters.forEach(RestorableTsFileIOWriter::makeMetadataVisible));
+            subVmWriters -> subVmWriters.forEach(RestorableTsFileIOWriter::makeMetadataVisible));
       } catch (StorageGroupProcessorException e) {
         logger.warn("Skip TsFile: {} because of error in recover: ", tsFileResource.getTsFilePath(),
             e);
@@ -2244,7 +2244,6 @@ public class StorageGroupProcessor {
    * @param filePartitionId the partition id of the new file
    * @return load the file successfully
    * @UsedBy sync module, load external tsfile module.
-   * @UsedBy sync module, load external tsfile module.
    */
   private boolean loadTsFileByType(LoadTsFileType type, File syncedTsFile,
       TsFileResource tsFileResource, long filePartitionId)

server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileProcessor.java

@@ -608,14 +608,14 @@ public class TsFileProcessor {
     try {
       TimeUnit.MILLISECONDS.sleep(1);
       File parent = tsFileResource.getTsFile().getParentFile();
-      File newVmFile = FSFactoryProducer.getFSFactory().getFile(parent,
+      return FSFactoryProducer.getFSFactory().getFile(parent,
           tsFileResource.getTsFile().getName() + IoTDBConstant.FILE_NAME_SEPARATOR + level
               + IoTDBConstant.FILE_NAME_SEPARATOR + System
               .currentTimeMillis() + VM_SUFFIX);
-      return newVmFile;
     } catch (InterruptedException e) {
       logger.error("{}: {}, closing task is interrupted.",
           storageGroupName, tsFileResource.getTsFile().getName(), e);
+      Thread.currentThread().interrupt();
       return null;
     } finally {
       vmFileCreateLock.writeLock().unlock();
@@ -716,7 +716,7 @@ public class TsFileProcessor {
         if (config.isEnableVm()) {
           logger.info("[Flush] flush a vm");
           File newVmFile = createNewVMFile(tsFileResource, 0);
-          if (vmWriters.size() <= 0) {
+          if (vmWriters.isEmpty()) {
             vmWriters.add(new ArrayList<>());
             vmTsFileResources.add(new ArrayList<>());
           }
@@ -1174,15 +1174,15 @@ public class TsFileProcessor {
       try {
         TimeUnit.MILLISECONDS.sleep(1);
         File parent = writer.getFile().getParentFile();
-        File newTmpFile = FSFactoryProducer.getFSFactory().getFile(parent,
+        return FSFactoryProducer.getFSFactory().getFile(parent,
             writer.getFile().getName() + IoTDBConstant.FILE_NAME_SEPARATOR + System
                 .currentTimeMillis()
                 + VM_SUFFIX + IoTDBConstant.PATH_SEPARATOR
                 + PATH_UPGRADE);
-        return newTmpFile;
       } catch (InterruptedException e) {
         logger.error("{}: {}, closing task is interrupted.",
             storageGroupName, tsFileResource.getTsFile().getName(), e);
+        Thread.currentThread().interrupt();
         return null;
       } finally {
         vmFileCreateLock.writeLock().unlock();

server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileResource.java

@@ -719,8 +719,8 @@ public class TsFileResource {
   }
 
   /**
-   * Used when load new TsFiles not generated by the server Check and get the time partition TODO:
-   * when the partition violation happens, split the file and load into different partitions
+   * Used when load new TsFiles not generated by the server Check and get the time partition
+   * TODO:when the partition violation happens, split the file and load into different partitions
    *
    * @throws PartitionViolationException if the data of the file cross partitions or it is empty
    */