#vulnerable code 
                                private void reSendLocalTx() throws NulsException {
        List<Transaction> txList = getLedgerService().getWaitingTxList();
        List<Transaction> helpList = new ArrayList<>();
        for (Transaction tx : txList) {
            if (TimeService.currentTimeMillis() - tx.getTime() < DateUtil.MINUTE_TIME * 2) {
                continue;
            }
            ValidateResult result = ledgerService.verifyTx(tx, helpList);
            if (result.isFailed()) {
                getLocalDataService().deleteUnCofirmTx(tx.getHash().getDigestHex());
                continue;
            }
            Transaction transaction = getLedgerService().getTx(tx.getHash());
            if (transaction != null) {
                getLocalDataService().deleteUnCofirmTx(tx.getHash().getDigestHex());
                continue;
            }
            helpList.add(tx);
            TransactionEvent event = new TransactionEvent();
            event.setEventBody(tx);
            getEventBroadcaster().publishToLocal(event);
        }
    } 
                            #location 2 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private void reSendLocalTx() throws NulsException {
        List<Transaction> txList = getLedgerCacheService().getUnconfirmTxList();
        List<Transaction> helpList = new ArrayList<>();
        for (Transaction tx : txList) {
            if (TimeService.currentTimeMillis() - tx.getTime() < DateUtil.MINUTE_TIME * 2) {
                continue;
            }
            ValidateResult result = getLedgerService().verifyTx(tx, helpList);
            if (result.isFailed()) {
                getLocalDataService().deleteUnCofirmTx(tx.getHash().getDigestHex());
                ledgerCacheService.removeLocalTx(tx.getHash().getDigestHex());
                continue;
            }
            Transaction transaction = getLedgerService().getTx(tx.getHash());
            if (transaction != null) {
                getLocalDataService().deleteUnCofirmTx(tx.getHash().getDigestHex());
                ledgerCacheService.removeLocalTx(tx.getHash().getDigestHex());
                continue;
            }
            helpList.add(tx);
            TransactionEvent event = new TransactionEvent();
            event.setEventBody(tx);
            getEventBroadcaster().publishToLocal(event);
        }
    }