Before0 2013-11-08
在hibernate中,运用doInHibernate,避免了手动open session和close session ,减少了一系列session关闭的麻烦。
公用的setParameter 方法,下面有调用,传入一个query 实例,和Map<String, Object> map 类型的参数
private void setParameter(Query query, Map<String, Object> map) {
if (map != null && !map.isEmpty()) {
Set<String> keySet = map.keySet();
for (String string : keySet) {
Object obj = map.get(string);
// 这里考虑传入的参数是什么类型,不同类型使用的方法不同
if (obj instanceof Collection<?>) {
query.setParameterList(string, (Collection<?>) obj);
} else if (obj instanceof Object[]) {
query.setParameterList(string, (Object[]) obj);
} else {
query.setParameter(string, obj);
}
}
}
}
updateByHql:
public void updateByHql(final String hql, final Map<String, Object> map) throws Exception {
template.execute(new HibernateCallback() {
@Override
public Object doInHibernate(Session session) throws HibernateException, SQLException {
Query query = session.createQuery(hql);
//调用set参数的方法
setParameter(query, map);
query.executeUpdate();
return null;
}
});
}
findByHql:
public List<Object> findByHql(final String hql, final Map<String, Object> map) throws Exception {
return (List<Object>) template.execute(new HibernateCallback() {
public List<Object> doInHibernate(final Session session) throws HibernateException, SQLException {
Query query = session.createQuery(hql);
setParameter(query, map);
/*
* StringBuffer sb = new StringBuffer(); Query query0 =
* session.createSQLQuery(sb.toString());//<STRONG>执行普通sql</STRONG> Query query1 =
* session.createQuery(sb.toString());// <STRONG>执行hql </STRONG>
*/
return query.list();
}
});
}
调用例子:
String hql = "from ABC where bb = :aa";
Map<String, Object> map = new HashMap<String, Object>();
map.put("aa", 22);
List<Object> cList = commonDao.findByHql(hql, map);
if (cList == null || cList.size() == 0)
return null;
else
return (ABC) cList.get(0);
update类似与query,只是没有返回参数