Spring 101
A 30 Minute Review by Matthew McCullough

❶ What Is Spring?
Don’t call me, I’ll call you

• Java Application Framework (Not JEE)
• Targets Web, Enterprise Applications
• POJO Centric
• Inversion of Control (IOC)
• Now called Dependency Injection (DI)

❷ Modularized
Alphabet Soup

• JDBC Wrapper
• JDO, iBatis, Hibernate, JPA helper
• Supplement to Struts, Tapestry
• Batch Processing Framework
• Timed Events
• JMS, JNDI, LDAP

❸ IOC/DI
Don’t call me, I’ll call you

• Core Spring capabilities
• Configure components from outside-in
• Counter to the usual constructor calling
out to everything it needs

Split Personalities
• DI/IOC can be used in three ways
• POJO Setters
• Constructors
• Service lookup (JNDI)

❹ Factory
But not the kind that Al Gore worries about

• POJO Centric
• BeanFactory creates beans
• Gives toggle choice between singleton
and instances
• Creates PROPER singletons
• Auto-wiring by name

❺ Aspects

• Supplement existing methods on the fly
• Terminology: Proxies, Weaving, AspectJ
• Weaving:
• Byte time
• Load time