#vulnerable code 
                                public void init() {
        accountService = NulsContext.getInstance().getService(AccountService.class);
        //default local account
        List<Account> list = this.accountService.getLocalAccountList();
        if (null != list && !list.isEmpty()) {
            Locla_acount_id = list.get(0).getId();
        }
    } 
                            #location 4 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public void init() {
        accountService = AccountServiceImpl.getInstance();
        //default local account
        List<Account> list = this.accountService.getLocalAccountList();
        if (null != list && !list.isEmpty()) {
            Locla_acount_id = list.get(0).getId();
        }
    }