[Springframework-developer] =?iso-8859-1?Q?Re:[Springframework-developer]_destroy-method?=

[=?iso-8859-1?Q?<jp....@ti...>]

Juergen,=0D=0A=0D=0AVery good! Sooner or later, this would to be made and=
 the sooner is the best. This enforces the strong side of Spring. =0D=0A=0D=
=0AJust that Spring is now so rich that a full book is the only documenta=
tion that could be at the high level of the framework. Clearly, so a book=
 exclusively about Spring (with some related topics such as Hibernate in =
Spring) will have to follow the framework a day or another. It will be as=
king for a lot of work but could drastically increase the use of Spring.=0D=
=0A=0D=0AThe Rod's i21 was really great, but Spring is going over all hop=
es. What a fantastic framework! =0D=0A=0D=0AJean-Pierre=0D=0A=0D=0A=0D=0A=
Rod, everybody,=0D=0A=0D=0AI've just introduced support for a "destroy-me=
thod", analogous to "init-method". There's also a respective DisposableBe=
an interface with a destroy method now, analogous to InitializingBean wit=
h its afterPropertiesSet. AbstractBeanFactory's new destroySingletons met=
hod invokes such destroy methods on each of its cached singletons. Obviou=
sly, this just makes sense for singletons: We don't keep track of prototy=
pe instances.=0D=0A=0D=0AI've also added a "close" method to the Applicat=
ionContext interface. The default implementation in AbstractApplicationCo=
ntext invokes destroySingletons on the underlying BeanFactory. ContextLoa=
derListener, ContextLoaderServlet, and FrameworkServlet close their respe=
ctive contexts on shutdown now. This allows for proper lifecycle of all m=
anaged singletons in a web application.=0D=0A=0D=0AThe rationale behind t=
his is that we create resource leaks without this: For example, a Commons=
 DBCP BasicDataSource and a Hibernate SessionFactory need to be closed on=
 shutdown of a web app. Else, the former doesn't properly close its remai=
ning connections, and the latter doesn't leave the JVM-level JCS cache in=
 a clean state.=0D=0A=0D=0AOn-the-fly restarting of a web app without res=
tarting the server requires proper resource handling. The BasicDataSource=
 issue is obvious: The database might run out of connections. The Hiberna=
te forums also state that there *are* issues with restarting when using a=
 JCS cache, that's why SessionFactory.close has been introduced in 2.0.=0D=
=0A=0D=0ALocalSessionFactoryBean implements DisposableBean now, to care f=
or proper SessionFactory closing. The recommendation for BasicDataSource =
is to define it as follows. Note that we don't need any wrapper or the li=
ke to achieve this, we're simply reusing the completely Spring-unaware Ba=
sicDataSource :-)=0D=0A=0D=0A  <bean id=3D"dataSource" class=3D"org.apach=
e.commons.dbcp.BasicDataSource" destroy-method=3D"close">=0D=0A    <prope=
rty name=3D"driverClassName"><value>com.mysql.jdbc.Driver</value></proper=
ty>=0D=0A    ...=0D=0A  </bean>=0D=0A=0D=0AI hope you consider this a val=
uable addition. If there aren't any objections, I'll commit it tonight. P=
lease, before taking a snapshot for the new module, ask me if I'm done! ;=
-)=0D=0A=0D=0AJuergen=0D=0A=0A=0A********** L'ADSL A 20 EUR/MOIS*********=
*=0ATiscali propose l'ADSL le moins cher du march=E9 : 20 EUR/mois et le =
modem ADSL offert ! =0APour profiter de cette offre exceptionnelle, cliqu=
ez ici : http://register.tiscali.fr/adsl/=0AOffre soumise =E0 conditions.=
=0A