Package COM.
Upstate.
Cellculture.
Om.
Persist;
Import Net.
sf.
Hibernate.
HibernateException;
Import Net.
sf.
Hibernate.
JDBCEXCEPTION;
Import Net.
sf.
Hibernate.
SESSION;
Import Net.
sf.
Hibernate.
SessionFactory;
Import org.
Apache.
COMMONS.
Logging.
Log;
Import org.
Apache.
COMMONS.
Logging.
Logfactory;
/ ** * this class is used to get hibernate sessions and may * also contain methods (in the fulure) To get dbconnections * or transactions from jndi. * /
public
Class ServiceLocator
{
// ~ static fields / initializers =========================================== ==
public
Final
Static
String session_factory = "hibernate / sessionFactory";
public
Static
Final
Threadlocal session =
New
Threadlocal
(
);
Private
Static sessionFactory sf =
NULL;
Private
Static ServiceLocator ME;
Private
STATIC log log = logfactory.
Getlog
ServiceLocator.
Class
);
Static
{
Try
{
ME =
New ServiceLocator
(
);
}
Catch
(
Exception E
)
{
Log.
Fatal
("
Error Occurred Initializing ServiceLocator
);
e.
PrintStackTrace
(
);
}
}
// ~ constructors =============================================== =============
Private serviceLocator
(
)
Throws HibernateException, JDBCEXCEPTION
{
}
/ / ~ Methods ============================================== ================== PUBLIC
Static session currentsssion
(
)
Throws PersistenceException
{
Session s =
(Session
Sense.
get
(
);
IF
(s ==
NULL
)
{
s = persistencemanager.
OpenSession
(
);
IF
LOG.
ISDebugene
(
)
)
{
Log.
Debug
"" Opened Hibernate Session. "
);
}
SESSION.
set
(s)
);
}
Return S;
}
public
Static
Void CloseSession
(
)
Throws HibernateException, JDBCEXCEPTION
{
Session s =
(Session
Sense.
get
(
);
SESSION.
set
(
NULL
);
IF
(s! =
NULL
)
{
IF
(s.
Isopen
(
)
)
{
S.
Flush
(
);
S.
Close
(
);
IF
LOG.
ISDebugene
(
)
)
{
Log.
Debug
"" Closed Hibernate session. "
);
}
}
}
Else
{
Log.
Warn
"" Hibernate session was inadvertly already closed. "
);
}
}
}
If you use Lazy Loading, you need to use a servlet filter
Java code:
Package COM.
Upstate.
Cellculture.
Filter;
Import Java.
IO.
IOEXCEPTION;
Import Javax.
servlet.
Filter;
Import Javax.
servlet.
FILTERCHAIN;
Import Javax.
servlet.
FilterConfig;
Import Javax.
servlet.
ServletException;
Import Javax.
servlet.
ServletRequest;
Import Javax.
servlet.
ServletResponse;
Import Javax.
servlet.
HTTP.
HTTPSERVLETREQUEST;
Import Javax.
servlet.
HTTP.
HttpservletResponse;
Import Javax.
servlet.
HTTP.
HttpSession;
Import Net.
sf.
Hibernate.
SESSION;
Import org.
Apache.
COMMONS.
Logging.
Log;
Import org.
Apache.
COMMONS.
Logging.
Logfactory;
Import COM.
Upstate.
Cellculture.
Om.
Persist.
PersistenceException;
Import COM.
Upstate.
Cellculture.
Om.
Persist.
ServiceLocator;
public
Class ActionFilter
IMPLEMENTS FILTER
{
// ~ static fields / initializers =========================================== ==
// ~ instance fields ================================================================================================================================================================================================ ===========
/ ** * The log instance for this class * /
PRIVATE log log = logfactory.
Getlog
ActionFilter.
Class
);
Private filterConfig filter =
NULL;
/ / ~ Methods ============================================== ==================
public
Voidin
(FilterConfig Filterconfig)
)
Throws servletexception
{
THIS.
FilterConfig = filter;
}
/ ** * destroys the filter. * /
public
Void Destroy
(
)
{
FilterConfig =
NULL;
}
public
Void DOFILTER
(ServletRequest Req, ServletResponse Resp, Filterchain Chain
)
Throws
IOEXCEPTION, ServletException
{
// Cast to the Types I want to us
HttpservletRequest Request = (httpservletRequest
Req;
HttpservletResponse response =
(Httpservletresponse
) response;
HttpSession session = request.
GetSession
(
True
);
Session SES =
NULL;
Boolean sessioncreated =
False;
Try
{
CHAIN.
Dofilter
(Request, Response
);
}
Finally
{
Try
{
ServiceLocator.
CloseSession
(
);
}
Catch
(
Exception EXC
)
{
Log.
Error
("
Error Closing Hibernate Session. ", EXC
);
EXC.
PrintStackTrace
(
);
}
}
}
public
Static session getSession
(
)
Throws PersistenceException
{
Try
{
Return ServiceLocator.
CurrentSession
(
);
}
Catch
(
Exception E
)
{
Throw
New PersistenceException
("Could Not Find Current Hibernate Session.", E
);
}
}
}
In addition, in order to set up the database, we will use some Manager classes, that is, DAO
Java code:
/ * * CREATED ON APR 28, 2003 * * /
Package COM.
Upstate.
Cellculture.
Om.
Persist;
Import Java.
Util.
List;
Import Net.
sf.
Hibernate.
Query;
Import Net.
sf.
Hibernate.
SESSION;
Import COM.
Upstate.
Cellculture.
Om.
TECHNICIAN
/ ** * @Author tmckinney * * Centralizes all access to the technicians table * /
public
Class TechnicianManager
{
Private
Static
List alltechnicians;
public
Static
Void save
(Technician Technician
)
Throws PersistenceException
{
Try
{
ServiceLocator.
CurrentSession
(
).
Save
(Technician
);
}
Catch
(
Exception E
)
{
Throw
New PersistenceException
("Could Not Save.", E
);
}
}
public
Static Technician RetrievebyPK
(Long TechnicianID)
)
Throws PersistenceException
{
Try
{
Technician Technician =
(Technician
ServiceLocator.
CurrentSession
(
).
Load
Technician.
Class,
New
Long
(TechnicianID)
)
);
Return techni;
}
Catch
(
Exception E
)
{
Throw
New PersistenceException
("Could Not Retrieve.", E
);
}
}
public
Static
List RetrieveAlltechnicians
(
)
Throws PersistenceException
{
IF
(alltechnicians ==
NULL
)
{
Try
{
Query Q = ServiceLocator.
CurrentSession
(
).
CREATEQUERY
("From Technician in
Class " Technician.
Class "ORDER BY UPPER
Technician.
Name
) "
);
Alltechnicians = Q.
List
(
);
SESSION.
Flush
(
);
}
Catch
(
Exception E
)
{
e.
PrintStackTrace
(
);
Throw
New PersistenceException
(e
);
}
}
Return Alltechnicians;
}
}
If you can use a TechnicianManager interface and a TechnicianManagerImpl Class. It is better. Pack all thrown exceptions via an exception defined.
Java code:
Package COM.
Upstate.
Cellculture.
Om.
Persist;
Import org.
Apache.
COMMONS.
LANG.
EXCEPTION.
NestableException;
/ ** * a general persistenceException That than thrown by all all ganager classes. * /
public
Class PersistenceException
Extends NestableException
{
// ~ constructors =============================================== =============
/ ** * constructor for personistenceException. * /
Public PersistenceException
(
)
{
Super
(
);
}
/ ** * constructor for persistenceException. * * @Param message * /
Public PersistenceException
(
String message
)
{
Super
(Message)
);
}
/ ** * Constructor for persistenceException. * * @Param message * @Param Cause * /
Public PersistenceException
String Message,
Throwable cause
)
{
Super
(Message, Cause
);
}
/ ** * Constructor for persistenceException. * * @Param Cause * /
Public PersistenceException
(
Throwable cause
)
{
Super
(Cause
);
}
}
