我们的一个小程序总是在open session的时候停止响应,而且非常规律得在操作第四次时停止。查阅很多资料,发现下面这篇文章很有启发,摘录如下:
前几天用spring+hibernate+struts写了个增/删/改/查的例子。调试期间问题就来了,当查询结果翻页好几次就没N久没有响应了。最后控制报错。网上查了,它说数据库连接(池)问题。
出现错误如下:
<2007-9-30 下午12时03分03秒 CST> <Error> <WebLogicServer> <BEA-000337> <ExecuteThread: '13' for queue: 'weblogic.kernel.Default' has been busy for "901" seconds working on the request "Http Request: /admin/school.do", which is more than the configured time (StuckThreadMaxTime) of "600" seconds.>
先说下我配置
1.环境:
spring 2.0.6,hibernate 3.2.3,struts 1.2.9,oracle 10.2,weblogic 8.1.4
jdbc是ojdbc14.jar
2.连接池用DBCP
<
bean
id
="dataSource"
class
="org.apache.commons.dbcp.BasicDataSource"
destroy-method
="close"
>
<
property
name
="driverClassName"
value
="${jdbc.driverClassName}"
/>
<
property
name
="url"
value
="${jdbc.url}"
/>
<
property
name
="username"
value
="${jdbc.username}"
/>
<
property
name
="password"
value
="${jdbc.password}"
/>
bean>
3.分页方法(参考springside的),此类继承HibernateDaoSupport
public
Page listByPage(Class entityClass,
int
pageNo,
int
pageSize, List criterions, List orders) {
Criteria criteria
=
createCriteria(entityClass, criterions);
CriteriaImpl impl
=
(CriteriaImpl) criteria;
//
先把Projection和OrderBy条件取出来,清空两者来执行Count操作
Projection projection
=
impl.getProjection();
//
获取总记录数
int
totalCount
=
((Integer) criteria.setProjection(Projections.rowCount()).uniqueResult()).intValue();
if
(totalCount
<
1
) {
return
new
Page();
}
//
加排序
if
(orders
!=
null
) {
for
(
int
i
=
0
; i
criteria.addOrder((Order) orders.get(i));
}
}
//
原来的投影
criteria.setProjection(projection);
int
startIndex
=
Page.getStartOfPage(pageNo, pageSize);
//
取得结果
List list
=
criteria.setFirstResult(startIndex).setMaxResults(pageSize).list();
return
new
Page(startIndex, totalCount, pageSize, list);
}
public
Criteria createCriteria(Class entityClass, List criterions) {
Criteria criteria
=
getSession().createCriteria(entityClass);
if
(criterions
!=
null
) {
for
(
int
i
=
0
; i
criteria.add((Criterion) criterions.get(i));
}
}
return
criteria;
}
另外,没有用OpenSessionInViewFilter,struts与spring的整合:DelegatingRequestProcessor、action path与bean name同名。
翻页不过10次,服务器就没响应了,最后出现上面的错误的了。
刚用weblogic,也刚用ssh套餐。郁闷。
前天解决了。
问题解决,问题的原因是数据库连接耗尽,我用HiberanteDaoSupport的getSession()方法取得Session后没有释放Session。
出问题的代码处(红色部分):
public
Criteria createCriteria(Class entityClass, List criterions) {
Criteria criteria
=
getSession().createCriteria(entityClass);
if
(criterions
!=
null
) {
for
(
int
i
=
0
; i
criteria.add((Criterion) criterions.get(i));
}
}
return
criteria;
}
用完Session释放后就没事了,调用HiberanteDaoSupport的releaseSession(session);方法后即可解决。
现在正确的代码:
public
Page listByPage(Class entityClass,
int
pageNo,
int
pageSize, List criterions, List orders) {
Session session
=
getSession();
//
创建criteria
Criteria criteria
=
session.createCriteria(entityClass);
//
为criteria添加criterions
createCriteria(entityClass, criteria, criterions);
CriteriaImpl impl
=
(CriteriaImpl) criteria;
//
先把Projection和OrderBy条件取出来,清空两者来执行Count操作
Projection projection
=
impl.getProjection();
//
获取总记录数
int
totalCount
=
((Integer) criteria.setProjection(Projections.rowCount()).uniqueResult()).intValue();
if
(totalCount
<
1
) {
return
new
Page();
}
//
加排序
if
(orders
!=
null
) {
for
(
int
i
=
0
; i
criteria.addOrder((Order) orders.get(i));
}
}
//
原来的投影
criteria.setProjection(projection);
int
startIndex
=
Page.getStartOfPage(pageNo, pageSize);
//
取得结果
List list
=
criteria.setFirstResult(startIndex).setMaxResults(pageSize).list();
//
释放hiberante资源,一定要释放,要不然就数据库连接耗尽.
releaseSession(session);
return
new
Page(startIndex, totalCount, pageSize, list);
}
public
Criteria createCriteria(Class entityClass, Criteria criteria, List criterions) {
if
(criterions
!=
null
) {
for
(
int
i
=
0
; i
criteria.add((Criterion) criterions.get(i));
}
}
return
criteria;
}