public class OpenSessionInViewInterceptor extends HibernateAccessor implements AsyncWebRequestInterceptor
Session
to the
thread for the entire processing of the request.
This class is a concrete expression of the "Open Session in View" pattern, which is a pattern that allows for the lazy loading of associations in web views despite the original transactions already being completed.
This interceptor makes Hibernate Sessions
available via the current
thread, which will be autodetected by transaction managers. It is suitable for
service layer transactions via
HibernateTransactionManager
or
JtaTransactionManager
as well as for
non-transactional execution (if configured appropriately).
NOTE: This interceptor will by default not flush the Hibernate
Session
, with the flush mode being set to FlushMode.NEVER
.
It assumes that it will be used in combination with service layer transactions
that handle the flushing: the active transaction manager will temporarily change
the flush mode to FlushMode.AUTO
during a read-write transaction,
with the flush mode reset to FlushMode.NEVER
at the end of each
transaction. If you intend to use this interceptor without transactions, consider
changing the default flush mode (through the
"flushMode"
property).
In contrast to OpenSessionInViewFilter
, this interceptor is
configured in a Spring application context and can thus take advantage of bean
wiring. It inherits common Hibernate configuration properties from
HibernateAccessor
,
to be configured in a bean definition.
WARNING: Applying this interceptor to existing logic can cause issues
that have not appeared before, through the use of a single Hibernate
Session
for the processing of an entire request. In particular, the
reassociation of persistent objects with a Hibernate Session
has to
occur at the very beginning of request processing, to avoid clashes with already
loaded instances of the same objects.
Alternatively, turn this interceptor into deferred close mode, by specifying "singleSession"="false": It will not use a single session per request then, but rather let each data access operation or transaction use its own session (as would be the case without Open Session in View). Each of those sessions will be registered for deferred close though, which will actually be processed at request completion.
A single session per request allows for the most efficient first-level caching,
but can cause side effects, for example on saveOrUpdate
or when
continuing after a rolled-back transaction. The deferred close strategy is as safe
as no Open Session in View in that respect, while still allowing for lazy loading
in views (but not providing a first-level cache for the entire request).
setSingleSession(boolean)
,
HibernateAccessor.setFlushMode(int)
,
OpenSessionInViewFilter
,
HibernateInterceptor
,
HibernateTransactionManager
,
SessionFactoryUtils.getSession(org.hibernate.SessionFactory, boolean)
,
TransactionSynchronizationManager
,
SessionFactory.getCurrentSession()
Modifier and Type | Field and Description |
---|---|
static String |
PARTICIPATE_SUFFIX
Suffix that gets appended to the
SessionFactory
toString() representation for the "participate in existing
session handling" request attribute. |
FLUSH_ALWAYS, FLUSH_AUTO, FLUSH_COMMIT, FLUSH_EAGER, FLUSH_NEVER, logger
Constructor and Description |
---|
OpenSessionInViewInterceptor()
Create a new
OpenSessionInViewInterceptor ,
turning the default flushMode to FLUSH_NEVER . |
Modifier and Type | Method and Description |
---|---|
void |
afterCompletion(WebRequest request,
Exception ex)
Unbind the Hibernate
Session from the thread and close it (in
single session mode), or process deferred close for all sessions that have
been opened during the current request (in deferred close mode). |
void |
afterConcurrentHandlingStarted(WebRequest request)
Called instead of
postHandle and afterCompletion , when the
the handler started handling the request concurrently. |
protected String |
getParticipateAttributeName()
Return the name of the request attribute that identifies that a request is
already intercepted.
|
protected boolean |
isSingleSession()
Return whether to use a single session for each request.
|
void |
postHandle(WebRequest request,
ModelMap model)
Flush the Hibernate
Session before view rendering, if necessary. |
void |
preHandle(WebRequest request)
Open a new Hibernate
Session according to the settings of this
HibernateAccessor and bind it to the thread via the
TransactionSynchronizationManager . |
void |
setSingleSession(boolean singleSession)
Set whether to use a single session for each request.
|
afterPropertiesSet, applyFlushMode, convertHibernateAccessException, convertJdbcAccessException, convertJdbcAccessException, disableFilters, enableFilters, flushIfNecessary, getDefaultJdbcExceptionTranslator, getEntityInterceptor, getFilterNames, getFlushMode, getJdbcExceptionTranslator, getSessionFactory, setBeanFactory, setEntityInterceptor, setEntityInterceptorBeanName, setFilterName, setFilterNames, setFlushMode, setFlushModeName, setJdbcExceptionTranslator, setSessionFactory
public static final String PARTICIPATE_SUFFIX
SessionFactory
toString()
representation for the "participate in existing
session handling" request attribute.public OpenSessionInViewInterceptor()
OpenSessionInViewInterceptor
,
turning the default flushMode to FLUSH_NEVER
.HibernateAccessor.setFlushMode(int)
public void setSingleSession(boolean singleSession)
If set to false, each data access operation or transaction will use its own session (like without Open Session in View). Each of those sessions will be registered for deferred close, though, actually processed at request completion.
protected boolean isSingleSession()
public void preHandle(WebRequest request) throws DataAccessException
Session
according to the settings of this
HibernateAccessor
and bind it to the thread via the
TransactionSynchronizationManager
.preHandle
in interface WebRequestInterceptor
request
- the current web requestDataAccessException
SessionFactoryUtils.getSession(org.hibernate.SessionFactory, boolean)
public void postHandle(WebRequest request, ModelMap model) throws DataAccessException
Session
before view rendering, if necessary.
Note that this just applies in single session mode
!
The default is FLUSH_NEVER
to avoid this extra flushing,
assuming that service layer transactions have flushed their changes on commit.
postHandle
in interface WebRequestInterceptor
request
- the current web requestmodel
- the map of model objects that will be exposed to the view
(may be null
). Can be used to analyze the exposed model
and/or to add further model attributes, if desired.DataAccessException
HibernateAccessor.setFlushMode(int)
public void afterCompletion(WebRequest request, Exception ex) throws DataAccessException
Session
from the thread and close it (in
single session mode), or process deferred close for all sessions that have
been opened during the current request (in deferred close mode).afterCompletion
in interface WebRequestInterceptor
request
- the current web requestex
- exception thrown on handler execution, if anyDataAccessException
TransactionSynchronizationManager
public void afterConcurrentHandlingStarted(WebRequest request)
AsyncWebRequestInterceptor
postHandle
and afterCompletion
, when the
the handler started handling the request concurrently.afterConcurrentHandlingStarted
in interface AsyncWebRequestInterceptor
request
- the current requestprotected String getParticipateAttributeName()
The default implementation takes the toString()
representation
of the SessionFactory
instance and appends PARTICIPATE_SUFFIX
.