Struts, JSF, Spring en Hibernate in Action

7/23/2019 Struts, JSF, Spring en Hibernate in Action

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1NLJUD 2005 20 December, 2005

IT IMPACT 2005

It is not important whether a technology will besuccessful or not, it is important to wonder how we

would react if it did...

Struts, JSF, Spring en Hibernate in action

by Ronald Koster


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Struts, JSF, Spring en Hibernate in action

For building Java/J2EE application one can choose form aextensive set of framework. The ones mentioned above are

among the most popular ones. This presentation will attempt toanswer the following questions:

What are the differences and matches of Struts and JSF?

Can they be combined? If so, would you want to? What is Spring and why is it called the glue framework?

What is Hibernate and why is it great?

How to combine Spring, Hibernate and Session Beans?


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Struts and JSF 1/4

Struts and JSF are MVCs for building web applications.

JSF is supposed successor of Struts.+ Managed Beans, EL, Event Driven

- More complex (bigger learning curve), Less documentation, Less transparent.

Tutorial by Marty Hall: http://www.coreservlets.com/JSF-Tutorial

JSF more event driven (like traditional GUIs) than Struts.

Struts: pure request/response driven. JSF: event driven but request/responseapproach still available too.

mGBA project: MyFaces (initially RI). Combining Struts and JSF: No, except for Tiles if you want to.


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Struts and JSF - 2/4 Struts flow of control

Jsp

invoke ActionX

Action

Servlet

FormX

ActionX

BL BeansUser

business method

reset

execute

target name

new/fetch

display

new

populate

store result

getters

Preceding

ActionOR

new: in case of request scope form

fetch: in case of session scope form

OR internal forward

If target is a JSP, else it

is another Action, in which

case this whole sequence

starts again.

BLBean =

Business Logic Bean =

Service Bean


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Struts and JSF 3/4 JSF flow of control(Faces request, Faces response)

Jsp1 Jsp2

submitinvoke BeanX.methodY

Faces

Servlet

BeanX and other

Jsp1 beans

BL Beans

User

target JSP name

new/fetch

display

populate beans

methodY

getters

business method A (by methodY)

business method B (by getters)

new: in case of request scope bean

fetch: in case of sessions scope bean

OR internal forward

Other

Jsp2 beans

new/fetch

gettersbusiness method C

(by getters)


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Struts and JSF 4/4 - Flow of control comparison

Struts:Model: Forms + BLBeans

Controller: Actions + ActionServletView: JSPs

JSF:Model: JSF-Beans + BLBeans

Controller: JSF-Beans + FacesServletView: JSPs

JSF-Bean can be both Model and Controller. Less strictenforcing of separation of Model and Controller!

For complex navigational flows it is a good idea to buildyour own MVC by differentiating between ControllerBeans

(aka. ActionBeans) and DataBeans.


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Spring 1/3 - What is Spring

Spring relies heavily on the Inverse of Control (IoC) designpattern using Dependency Injection.

(Hollywood principle: Dont call us, we will call you).NB. JSF Managed beans: IoC, very much like Sping!

Provides extremely convenient consistent encapsulation ofvirtually all major APIs and frameworks: the glueframework.

Suited for J2SE and J2EE. J2EE != EJB. Spring has virtually crushed EJBs:

Entity Beans: Dead: use Spring-JDBC and ORM.

Stateless Session Beans: Dead: use Spring, if needed in combination withload balancer (for clustering) and application server (as JTA framework).

Stateful Session Beans: still alive, but who has ever used them?

Message Driven Beans: still alive, but Spring alternative is getting better. Ergo: Usually no need for EJBs and EJB container. However, Web/Servlet

container remains to be needed.


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Spring 2/3 - Properties

Provides Bean lifecycle management (through IoC). Has its own web MVC.

But integrates well with JSF as well(see org.springframework.web.jsf.DelegatingVariableResolver).

Encapsulates Hibernate and other Object RelationalMapping (ORM) frameworks.

Encapsulates JDBC (JDBC problems usually vanishwith

Spring-JDBC!). Encapsulates transaction management and JTA. Has own AOP framework and encapulates others. Has security framework (Acegi).

Encapsulates all major Remoting protocols (HttpInvoker,Hessian, Burlap, SOAP, RMI, EJBs).

Encapsulates JMX. And more!


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Spring 3/3 - Usage

Inverse of Control (IoC): Spring managed beans, configuredthrough XML files, less Java code. IoC is very simple to use andvery powerful.

Allows piece by piece build of J2EE application, starting with asimple standard edition application. This enables architecturaldecisions to be postponed.

Pick what you need. Can easily be combined with all majorAPIs and frameworks.

Encapsulates en glues together APIs and other frameworks.

Simply use it! It will make things easier.


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Hibernate 1/2 - What is Hibernate

Hibernate is an Object Relational Mapping (ORM) framework.

Many other frameworks exist, but Hibernate is probably themost popular one.

Entity Beans are dead. EJB3 will be like Hibernate.

Any Plain Old Java Object (POJO) can be persisted.

Hibernate is a simple andpowerful framework.


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Hibernate 2/2 - Usage

Key features:

1. Define database through hbm.xml files.2. Generate database create schema script (SQL) andpersistent

Java classes (POJOs) representing the database tables from

these hbm.xml files.NB. The other way around: generate hbm.xml files from an existiis possible also.

3. HQL and Hibernate API.

Do use Spring encapsulation.

Hibernate DAOs can be placed behind Session Beans. Butoften you dont (see Spring has virtually crushed EJBs).


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Model Architecture

SpringMVC / JSF

Spring Remoting

Service Spring Beans

Spring JDBC Spring + Hibernate

Spring JTA

SpringSecurity

Spring Security

JSPs + Spring / JSF Beans Remote Services

DAO Spring Beans

: framework: my code


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Links

Struts: http://struts.apache.org

JSF: http://java.sun.com/j2ee/javaserverfaces MyFaces: http://myfaces.apache.org Spring: http://www.springframework.org Hibernate: http://www.hibernate.org

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Struts, JSF, Spring en Hibernate in Action