import org.apache.hadoop.hdfs.qjournal.protocol.QJournalProtocolProtos.CanRollBackResponseProto; //导入依赖的package包/类
@Override
public Boolean canRollBack(String journalId, StorageInfo storage,
    StorageInfo prevStorage, int targetLayoutVersion) throws IOException {
  try {
    CanRollBackResponseProto response = rpcProxy.canRollBack(
        NULL_CONTROLLER,
        CanRollBackRequestProto.newBuilder()
          .setJid(convertJournalId(journalId))
          .setStorage(PBHelper.convert(storage))
          .setPrevStorage(PBHelper.convert(prevStorage))
          .setTargetLayoutVersion(targetLayoutVersion)
          .build());
    return response.getCanRollBack();
  } catch (ServiceException e) {
    throw ProtobufHelper.getRemoteException(e);
  }
}
 

import org.apache.hadoop.hdfs.qjournal.protocol.QJournalProtocolProtos.CanRollBackResponseProto; //导入依赖的package包/类
@Override
public CanRollBackResponseProto canRollBack(RpcController controller,
    CanRollBackRequestProto request) throws ServiceException {
  try {
    StorageInfo si = PBHelper.convert(request.getStorage(), NodeType.JOURNAL_NODE);
    Boolean result = impl.canRollBack(convert(request.getJid()), si,
        PBHelper.convert(request.getPrevStorage(), NodeType.JOURNAL_NODE),
        request.getTargetLayoutVersion());
    return CanRollBackResponseProto.newBuilder()
        .setCanRollBack(result)
        .build();
  } catch (IOException e) {
    throw new ServiceException(e);
  }
}