private ByteBuffer readByteBufferFromWALFile() throws WALPipeException {
    try {
      return walEntryPosition.readByteBufferViaCacheAfterCanRead();
    } catch (Exception e) {
      throw new WALPipeException("Fail to get value because the file content isn't correct.", e);
    }
  }
Get this handler's value.

@throws WALPipeException when failing to get the value.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/wal/utils/WALEntryHandler.java