Download Spring Framework

Wishing for Spring
Presented by Robert Kaul
The Spring Framework
•Where did it come from?
•Why use it?
•What is it?
•Who uses it?
•How does it work?
History of Spring
 It all started with some meteorologists…
History of Spring
 First milestone release 1.0 in March 2004
 by Rod Johnson J2EE developer
 2.0 October 2006
 2.5 November 2007
 3.0 December 2009
Why use Spring?
 Designed for
 Consistency
 Maintainability
 Simplicity
 Jolt Productivity Award in 2006
 For “Jolting” the industry
 JAX Innovation Award in 2006
 Java Specific innovation
J2EE without Spring
 Brought standardization to core middle-tier concepts.
 Transaction management (aka talking to a database)
 Over-complex
 Distributed applications hard to develop, debug, deploy and
maintain.
 Take excess effort to develop
 Disappointing performance
J2EE without Spring
 Excessive amounts of “Plumbing” code
 Code reviews showing large amounts of code that doesn’t
do anything
 Try/catch blocks to acquire and release JDBC(Java database
connection) resources
 Writing and maintaining plumbing code drains resources
 Attempts at design patters resulted in workarounds for
application programing interfaces(APIs) I.E. (JDBC)
Spring into Easier Consistency
 Helps Structure whole applications
 Takes care of “plumbing” code
 Dependency injection
 Aspect oriented programming
 Managing transactions
 Security
 Social networking
Who would want to use Spring
How does it?
 Wire beans
 Inject dependencies
 Declare beans
 AOP
 Database transactions
 Web applications
 Security
Spring’s Container
 Inversion of control container
 Keeps track of all application resources
 Allows serialization of objects
 Using dependency injection
Spring’s Container
 Wired beans interact with each other and are kept track of
by the container
Dependency injection
 Good dependency injection should leave code decoupled
 Easy to maintain
 Easy to test
 Should be able to inject with the injected knowing it.
Declaring Beans
 Assume a ContactablePerson that implements a Person
Public class ContactablePerson implements Person {
private Phone phone;
public ContactablePerson(Phone phone){
this.phone = phone;//phone is injected
}
public void AnswerPhone( throwDialException){
phone.answer();
}
}
Declaring Beans
 The Spring configuration files are written in XML
Declaring Beans
 Why configuration files?
 For the sake of consistency
 Everything in spring has some form of configuration file.
 This is a simple fast way of easing a developer into
something they will have to use on something much
more complex.
Aspect-Oriented Spring
 Point cut with advice before an action or after an action.
 Primarily for keeping track of data access; whens,
wheres and how-manys
 To improve performance or get rid of something unused.
 Easy to update a current program using AOP
 Used for other things as well
 Spring uses this for it’s security features
Aspect-Oriented Spring
 This is part of a MovieWatchers class
AOP Spring Config
Database access with Spring
 J2EE does it so does Spring
 Cuts down the need for “Plumbing” code
 Using the Templating design pattern.
 Allows for different types of databases.
 Achieves communication through eight different
Templates
Template classes
JDBC’s Exceptions v. Spring’s
Database access with Spring
 Why Template database access?
 Always going to have the same 7 steps throughout the
interaction
 Establish a connection
 Start transaction
 Execute query
 Return data
 Commit/rollback the transaction
 Close connection
 Handle exceptions
 Developers only really want to execute the query.
Database access with Spring
 Spring allows the developer to change their query while
handling the other 6 steps
 This leads to
 Higher quality queries
 Higher productivity
Database access with Spring
Spring’s Model-view-controller
 The Spring way of allowing a user to view data on the
web
 Has different view capabilities
 The Most common is a Java Server Page or JSP
 For all practical purposes is just smart HTML page linked to
an data-access-object’s methods.
 For example home.jsp would be linked to
HomeController.java
Spring’s Model-view-controller
 Allows for web pages to have a Tile Layout
 Tile: piece of web page defined separately
 For example, sidebar.jsp
 Also allows for a type of inheritance sidebarCalendar.jsp
 Makes maintenance easier
 Moving pieces easier than rewriting a whole HTML page
 Mygreatlakes.org
Different View Resolvers
 Here they are...
 InternalResourceViewResolver // used for the example
 ContentNegotiatingViewResolver
 BeanNameViewResolver
 FreeMarkerViewResolver
 JasperReportsViewResolver
 ResourceBundleViewResolver
 TilesViewResolver
 VelocityViewResolver
 XmlViewResolver
 XsltViewResolver
Life cycle of a request
Spring Model-view-Controller
 Generally Start with a home page a work out through
the navigation
 Craig Wall’s Spring in Action 3.0 Spitters example
 Spitters is a twitter-like web application
 HomeController used to welcome users to Spitters by
displaying recent spits.
Spitters HomeController
Spitters HomeController
 @Controller marker indicates that this is a controller
class allows spring to register it as a bean and keep
track of it
 @inject updates the context file automatically with the
ref tag injecting the SpitterService upon creation
 @RequestMapping this marks the method to handle
requests from “/” or from “/home” it also gets the Map
of Strings to Object and stores it in a model map to be
displayed later by the view
 The return “home” is the name of the view on which the
map should be rendered
Rendering Spring Views
Rendering Spring Views
 <%@taglib prefix= these imports allow you to
accomplish smart HTML
 things like iterate through a map
 ${variableName} is a variable reference from the
homeController bean
 <s:url value= Spring’s way of creating context that is
relative to a particular Spitter
 Also used for referencing static content like images
 This example doesn’t show everything
 input & file upload.
Spring Security
 Features…
 Easy Configuration using Spring Dependency Injection
 Non-Intrusive Setup
 Don’t have to deploy libraries to your Server
 Non-Invasive
 Keeps security out of objects
 Pluggable Architecture
 Easy to replace, customize or extend parts
 Password encoding
 Caching
 LDAP Support
 Supports HTTP Digest authentication
 Never sends password over a wire
Spring Security
 Any web application using personal identification data
must have:
 Authentication
 Authorization
 Web request level and method level
 Accomplished using
 Dependency injection
 Aspects
Conclusion
 Features…
 Dependency Injection
 Declaring beans
 Aspect-Oriented ability
 Point cuts
 Database access
 Templating and Templates
 Spring Model-view-controller
 Tile Layouts
 Rendering views
 Views
 Things I didn’t talk about…
 Web flow capabilities REST
 Transaction management
 Wiring a bean using spEL regular expression language…
References
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Walls, Craig, Mr. Spring in Action. Illus. Marija Tudor. Ed. Sebastian Stirling. 3rd ed. Shelter
Island: Manning, 2011. Print.
"SpringSource." SpringSource. VMware, 2011. Web. 7 Nov. 2011.
<http://www.Springsource.org/
features/modern-web>


Jose, Benoy. "The Spring Framework." Rev. of Spring Framework. http://javaboutique.
internet.com,
2011. Web. 13 Oct. 2011.
<http://javaboutique.internet.com/tutorials/Spring_frame/>.
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Johnson, Rod. "Introduction to the Spring Framework." theserverside. TechTarget, 1 May
2005. Web. 2
Nov. 2011. <http://www.theserverside.com/news/1364527/
Introduction-to-the-Spring-Framework>.
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Javabeat, Niraimathi. "Extending ViewResolver and Chaining ViewResolvers in Spring MVC."
javabeat. N.p., 2011. Web. 13 Nov. 2011. <http://www.javabeat.net/articles/
247-extending-viewresolver-and-chaining-viewresolvers-in-sp-1.html>.
Questions