保存大量实体时，Hibernate会导致内存不足异常

        Session session = headerdao.getSessionFactory().openSession();
        Transaction tx = session.beginTransaction();

        int count = 0;
        String[] nextLine;

        while ((nextLine = reader.readNext()) != null) {
            try {

                if (nextLine.length == 23
                        && Integer.parseInt(nextLine[0]) > lastIdInDB) {
                    JournalHeader current = parseJournalHeader(nextLine);
                    current.setChain(chain);
                    session.save(current);
                    count++;
                    if (count % 100 == 0) {
                        session.flush();
                        tx.commit();
                        session.clear();
                        tx.begin();
                    }
                    if (count % 10000 == 0) {
                        LOG.info(count);
                    }

                }

            } catch (NumberFormatException e) {
                e.printStackTrace();
            } catch (ParseException e) {
                e.printStackTrace();
            }

        }
        tx.commit();
        session.close();

parseJournalHeader()

String[]