package
com
.
dao
;
import
java.util.List
;
import
org.hibernate.HibernateException
;
import
org.hibernate.Session
;
import
org.hibernate.SessionFactory
;
import
org.hibernate.Transaction
;
import
org.hibernate.cfg.Configuration
;
import
com.IConst.IConst
;
public
class
BaseDao
{
private
static
Configuration
cf
;
private
static
SessionFactory
sf
;
/* 实例化线程池 */
private
ThreadLocal
<
Session
>
thread
=
new
ThreadLocal
<
Session
>();
static
{
init
();
}
/*
* 单例模式
* */
private
static
synchronized
void
init
()
{
try
{
if
(
null
==
cf
||
null
==
sf
)
{
cf
=
new
Configuration
().
configure
();
sf
=
cf
.
buildSessionFactory
();
}
}
catch
(
HibernateException
e
)
{
e
.
printStackTrace
();
}
}
/*
* open方法
* */
private
void
open
()
throws
Exception
{
/* 先从线程池中取 */
Session
session
=
thread
.
get
();
/* 取不到，利用工厂新建 */
if
(
null
==
session
)
{
session
=
sf
.
openSession
();
/* 将新建的session放入线程池 */
thread
.
set
(
session
);
}
}
/*
* close方法
* */
private
void
close
()
{
try
{
/* 从线程池中取 */
Session
session
=
thread
.
get
();
/* 取到，关闭 */
if
(
null
!=
session
)
{
session
.
close
();
/* 清空线程池 */
thread
.
set
(
null
);
}
}
catch
(
HibernateException
e
)
{
e
.
printStackTrace
();
}
}
/*
* 执行增\删\改
* */
public
boolean
update
(
Object
obj
,
int
type
)
{
Session
session
=
null
;
Transaction
tran
=
null
;
try
{
open
();
/* 取出session */
session
=
thread
.
get
();
/* 打开事务 */
tran
=
session
.
beginTransaction
();
switch
(
type
)
{
case
IConst
.
DELETE
:
session
.
delete
(
obj
);
break
;
case
IConst
.
INSERT
:
session
.
save
(
obj
);
break
;
case
IConst
.
UPDATE
:
session
.
update
(
obj
);
break
;
}
/* Hibernate的事务机制是先将其保存在缓存中 */
/* 只有commit以后，才将事务提交 */
/* 提交事务 */
tran
.
commit
();
return
true
;
}
catch
(
Exception
e
)
{
if
(
null
!=
tran
)
{
tran
.
rollback
();
}
e
.
printStackTrace
();
}
finally
{
close
();
}
return
false
;
}
/*
* 查询方法
* */
public
List
select
(
String
sql
)
{
Session
session
=
null
;
try
{
open
();
session
=
thread
.
get
();
return
session
.
createQuery
(
sql
).
list
();
}
catch
(
Exception
e
)
{
e
.
printStackTrace
();
}
finally
{
close
();
}
return
null
;
}
}
