Spring - in NutShell

Advantages of Spring:
    1) Layered Arch (only take what you need !! )
    2) Enables POJO Programming
    3) DI & IOC simplifies JDBC
    4) Open Source

Advantages of IoC:
    1) Lesser Source Code
    2) Making Application - more testable
          a) no need of Singletons
          b) no need of DNS lookups
    3) Loose Coupling
    4) IOC Containers support
               a) Eager Instantiation
               b) Lazy Loading of Services
Injections:
     1) Setter Injection
     2) Constructor Injection

Modules:
     1) Core Container
     2) Spring- Context
     3) Spring- AOP
     4) Spring-DAO
     5) Spring-ORM
     6) Spring- Web Module
     7) Spring- MV Framework

Advantages of Application Context:
   1) Resolving "text Messages"
   2) Support for "internationalisation"
   3) Generic way to load  - "File Resources"
   4) Sending Events to BEANs (which registered as Listeners)

Multiple Context Files:
    Splitting Web Application Context into
                   1) Persistance.xml
                   2) Transaction.xml
                   3) Service.xml