Spring Framework Intro

8/8/2019 Spring Framework Intro

1/26

An Introduction to the Spring Framework


2/26

What is the Spring Framework?

Spring is a Lightweight Application

Framework Where Struts, WebWork and others can be

considered Web frameworks, Spring

addresses all tiers ofan application

Spring provides the plumbing so that you

dont have to!


3/26

Spring Framework History

Started 2002/2003 by Rod Johnsonand Juergen Holler

Started as a framework developedaround Rod Johnsons book ExpertOne-on-One J2EE Design andDevelopment

Spring 1.0 Released March 2004 2004/2005 Spring is emerging as a

leading full-stack Java/J2EEapplication framework


4/26

Spring == J2EE Application Server?

Spring is NOT a J2EE application server

Spring can integrate nicely with J2EEapplication servers (or any Java

environment)

Spring can, in many cases, elegantly replace

services traditionally provided by J2EE

application servers


5/26

Lessons Learned from Struts

Before Struts, everyone wrote their own front

controllers (orYIKES! put their controller logic in JSP) After Struts, the custom front controllers could be

thrown out

Developers focus on solving business problems

Productivity Gain!

But with Struts (and most of the other web

frameworks) you still have to write your own

business delegates or service layers


6/26

Spring Can Help!

Spring brings a consistent structure to your entireapplication

Spring provides a consistent way to glue your wholeapplication together

Spring provides elegant integration points withstandard and defacto-standard interfaces: Hibernate,JDO, TopLink, EJB, RMI, JNDI, JMS, Web Services,

Struts, etc. Just as Struts did on the web tier, we can realize

huge productivity gains by not having to write thecommon integration points across your application


7/26

Spring Framework Mission Statement(continued)

The authors of Spring aim that:

Spring should be a pleasure to use Your application code should not depend on Spring

APIs

Spring should not compete with good existing

solutions, but shouldfoster integration. (Forexample, JDO and Hibernate are great O/R mapping

solutions. We don't need to develop another one.)


8/26

Spring Overview

from springframework.org

Note: Spring distribution comes as one big jarfile and alternatively as a series o

fsmallerjars broken out along the above lines (so you can include only what you need)


9/26

But really, what ISSpring?

At its core, Spring provides:

An Inversion ofControl Container

Also known as Dependency Injection (Fowlers term)

An AOP Framework

Spring provides a proxy-based AOP framework

You can alternatively integrate with AspectJ or AspectWerkz

A Service Abstraction Layer

Consistent integration with various standard and 3rd party APIs

These together enable you to write powerful, scalableapplications using POJOs.


10/26

Seriously though, what ISSpring?

Spring at its core, is a framework forwiring up your entire application

BeanFactories are the heart ofSpring


11/26

BeanFactories

A BeanFactory is typically configured in an

XML file with the root element: The XML contains one or more

elements

id (or name) attribute to identify the bean

class attribute to specify the fully qualified class


12/26

BeanFactories

By default, beans are treated as singletons

Can also be prototypesHere is an example:

The beans IDThe beans fully-

qualified classname

Maps to a setPoolSize() call


13/26

Property Values forBeanFactories

Strings and Numbers

Arrays and Collections

42

Jim

Basket Weaving

Break Dancing


14/26

Property Values forBeanFactories(continued)

The real magic comes in when you can set

a property on a bean that refers to anotherbean in the configuration:

This is the basic concept

of Inversion of Control

calls setWidgetDAO(myWidgetDAO)

where myWidgetDAO is another bean

defined in the configuration


15/26

Dependency Injection

(Inversion of Control)

Complicated sounding terms for a fairly

simple concept The Hollywood Principle: Dont call

me, Ill call you

Dependencies used from within a beanarent asked for outwardly, but are

injected into the bean by the container


16/26

Dependency Injection

(Inversion of Control)

Eliminates lookup code from within your

application Allows for pluggablity and hot swapping

Promotes good OO design

Enables reuse ofexisting code

Makes your application extremely testable


17/26

A Very Special BeanFactory:

the ApplicationContext

An ApplicationContext is a BeanFactory,

but adds framework features such as: i18n messages

Event notifications

This is what you will probably most often use

in your Spring applications


18/26

Service Abstraction Layers

Spring provides abstraction for:

Transaction Management JTA, JDBC, others

Data Access JDBC, Hibernate, JDO, TopLink, iBatis

Email Remoting

EJB, Web Services, RMI, Hessian/Burlap


19/26

Service Abstraction Layers

Benefits:

No implicit contracts with JNDI, etc. Insulates you from the underlying APIs

Greater reusability

Spring abstractions always consist of interfaces

This makes testing simpler

For data access, Spring uses a generic transactioninfrastructure and DAO exception hierarchy that iscommon across all supported platforms


20/26

Spring on the Web Tier

Spring integrates nicely with Struts,

WebWork, JSF, Tapestry, Velocity and otherweb frameworks

Spring also provides its own web framework,

Spring Web MVC


21/26

Spring on the Web Tier Spring MVC

The Spring MVC Framework offers a simple

interface based infrastructure for handingweb MVC architectures

Spring MVC components are treated as first-

class Spring beans

Other Spring beans can easily be injected intoSpring MVC components

Spring MVC components are easy to test


22/26

On to the examples

( See http://www.zabada.com/technology/Wiki.jsp?page=SpringRecipes )


23/26

Spring Related Tools and Add-Ons

ACEGI Security - comprehensive security services for the SpringFramework

Spring IDE - graphical user interface for the configuration files used bythe Spring Framework

Spring BeanDoc - tool that facilitates documentation and graphing ofSpring bean factories and application context files

XDoclet Spring Tags - support for generating Spring XML config filesfrom annotations in Java classes (you could also use JDK1.5annotations to achieve this)

SpringW

eb Flow -for web applications with demanding page

flowrequirements

AppFuse Not really a tool or add-on, but AppFuse is Matt Raible'sproject to jumpstart your Java web projects. It uses Spring at it's coreand studying it is a great way to learn about Spring.

Spring Framework .NET Spring Clone for the Dark Side


24/26

Spring Framework / Spring Related

References

The Official Spring Reference Manual

http://www.springframework.org/docs/reference/Introduction to Spring by Rod Johnson

http://www.theserverside.com/articles/article.tss?l=SpringFramework

Spring in Action by Craig Walls and Ryan Breidenbach

Pro Spring by Rob Harrop and Jan Machacek

J2EEWithout EJB by Rod Johnson and Juergen Holler

Expert One-on-One J2EE Design and Development by Rod JohnsonSpring Developers Notebook by Bruce Tate and Justin Gehtland

Better, Faster, Lighter Java by Bruce Tate and Justin Gehtland

Spring Live by Matt Raible

Professional Java Development with the Spring Framework

by many of the core Spring developers: Coming in July 2005


25/26

Wrap Up

Questions/Comments?

Feedback is appreciated!

Email me: [email protected]

Were Hiring For A Few Positions

Senior Java Developer

Mid-level Java Developer

Spring/Hibernate and other relevant Java technologies

Let me know ifyoure interested: [email protected]


26/26

Credits

Thanks to the Spring Framework Team. Sees

pringframew

ork.org Much of the content in this presentation was

inspired by presentations by Rod Johnson

and Craig Walls

Documents

Spring Framework Intro