public List<AccountPO> search(String key) throws RemoteException {
    // TODO
    List<AccountPO> list = new ArrayList<AccountPO>();
    // 符合该关键字的po都加载到list里面
    for (AccountPO po : accounts) if (po.getName().contains(key)) list.add(po);

    return list;
  }
  private boolean update() throws RemoteException {
    try {

      FileWriter fw = new FileWriter(file);
      fw.write("");

      System.out.println(accounts.size());
      for (AccountPO po : accounts) {
        // 将列表中的数据再一次的更新到Account.txt文件中去
        fw.append(po.getName() + " " + po.getAccountID() + " " + po.getBalance() + "\n");
        fw.flush();
      }
      fw.close();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    return true;
  }