string 转换成date
String date="2014-06-26 10:09:22.819"；	SimpleDateFormat sdf = new SimpleDateFormat(					"yyyy-MM-dd HH:mm:ss.SSS");Date lastupdated = sdf.parse(date);

	private String changedtos(Date date) {		// TODO Auto-generated method stub		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");		String ss = sdf.format(date);		System.out.println(ss);		return ss;	}

// date以降のmessage		try {			Query query = em					.createQuery(							"select e from MessageEntity e where e.groupId = :groupId AND :date < e.date"							+ " order by e.date asc",							MessageEntity.class);			query.setParameter("groupId", groupId);			query.setParameter("date", date);			return query.getResultList();		} finally {			em.close();		}