Spring

Spring?
• Inversion of control
• Dependency Injection

• DEPENDENCY INJECTION
Atunci cand :
• public Car buildCar() {
Car car = new Car();
Engine engine = new Engine();
car.setEngine(engine);
return car;
}
- Scriem cod ca asta si vrem sa-i impresionam pe
altii;

• INVERSION OF CONTROL
Atunci cand :
• public Car buildCar() {
Car car = new Car();
Engine engine = new Engine();
car.setEngine(engine);
return car;
}
… si chestia de mai sus, o face Springu’

• Cool stuff:
– Roo - roo generate controller ;)
– Easy configuration with xml;
– Templates for Hibernate DAO;
– AOP features: aspects, advices, pointcuts ☺
– Easy to configure a project with it:
– Standard set of libraries;
– Many examples;
– Good documentation and many books;
– Its so full of patterns! ☺

Container Configuration
• Dependency Injection
<bean id=“myCar" class=“gm.Ford">
<property name=“engine" ref=“renaultEngine" />
</bean>
<bean id=“renaultEngine" class=“renault.engines.RenaultEngine“/>
• Inversion of control
myCar = context.getBean(“myCar”);
• Service locator
Is what spring is using for retrieving the objects from its container;

Fast configuration
• Autowiring
<bean id="sequenceGenerator“ class="SequenceGenerator” autowire="byType">
</bean>
<bean id="datePrefixGenerator” class="DatePrefixGenerator">
class SequenceGenerator {
public SequenceGenerator(DatePrefixGenerator generator) {…}
}
• Scan package
<context:component-scan base-package=“org.mypackage"/>

…bean creation
• Prototype (instance/request)
• Singleton (instance/IOC container)
• Session/Request (instance/session/request)
• Proxying:
• Necessary for AOP (see proxy pattern)

Aspects
• Advice
• Ex: logging before and after
• Pointcut
• Ex: account.putMoney()
• Aspect
– Advice + Pointcut:
Log(“[Enter]putMoney”)
Account.putMoney();
Log(“[Exit]putMoney”)

Externalized configuration
• @Controller
• @RequestMapping
• @Aspect
• @Autowired

QA?
http://alexsisu.posterous.com/
alexandru.sisu@gmail.com

Resources
• http://www.springsource.org/
• http://www.springbyexample.org
• http://www.springsource.org/roo