seminar report on s5

8/12/2019 Seminar Report on s5

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WEB APPLICATION FRAMEWORKS IN JAVA MCA 2011

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MCA@NCERC CALICUT UNIVERSITY

1.INTRODUCTION

Earlier it was very hard to develop a complex web applications. Think of a framework

as a bridge that will help you code faster and easier. A web application framework (WAF) is

a software framework that is designed to support the development of dynamic websites, web

applications, web services and web resources. The framework aims to alleviate the overhead

associated with common activities performed in web development. For example, many

frameworks provide libraries for database access, templating frameworks

and session management, and they often promote code reuse. The majority of Web

frameworks are exclusively server-side technology. By using an appropriate framework, a

developer can often save a significant amount of time building a web site. Each framework is

different, but many provide a variety of useful features. By using a framework, a developer

avoids having to re-implement these same features for each web application they create.

A Web framework is a collection of packages or modules which allow developers to

write Web applications or services without having to handle such low-level details as

protocols, sockets or process/thread management.


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2.WEB FRAMEWORKSA web application framework (WAF) is a software framework that is designed to

support the development of dynamic websites, web applications, web services and web

resources. Web frameworks provide many typical website components right out of the box,

such as user management functionality which might otherwise take months of custom

development to build. Web frameworks are designed to be reused.

Communities of users and developers spring up around web frameworks where ideas

can be shared and knowledge can be captured. Add-ons, themes, plugins, widgets are all

names for things which develop within web framework communities and enable further rapid

customization of your website. The rapid build of basic website components and ease of

customization leads to large scale time and cost savings. Frameworks can into your way, as

they have made certain choices. How much they are constraining depends on the frameworks,

your experience with it, and what you are trying to accomplish. The first time around you use

a framework for something that it is good at, you are going to be impressed at how easy it

was to accomplish your task. Before long however, you might become so used to the benefits

that a frameworks brings that you wont even notice what the framework is doing for you

anymore; its now in the background. And humans are much attuned to pain, so the pain

points are going to remain.

A framework in context of software development is a set of prewritten code or

libraries which provide functionality common to a whole class of applications. The

framework can be seen as a base or a skeleton to build upon. In relation to libraries a

framework gives a broader span of functionalities. Libraries are often more focused on

solving a narrow scope. Typically a framework provides a predefined structure for the

application. The purpose of using a framework is basically to speed up development by nothaving to rewrite features and structure that are commonly used in most web applications.

Instead of inventing the wheel over and over again the developer has many wheels

(functions/features etc) that are already tested and working properly. Most (web) frameworks

today are free to use and are open source and anyone can join to contribute in some way.

Notice, web frameworks is a trend of later part of first decennium of third millennium.

Experience by using the framework and thus being able to help others. Most of the

frameworks today have quite many contributors and users (developers) inspecting the sourcecode for security risks and evil pieces of code.


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3.BACKGROUNDThe World Wide Web (often known as the web) was created in 1990 and in the

beginning the web was very static. The user could not interact much with the content, and to

update a piece of text (or something else as well) in a published material on the web, the

author had to edit the page locally and upload it to the server. To get rid of this manual work

the Common Gateway Interface (CGI) standard was created for interfacing external

applications with web servers. CGI created a new process for each request to the server

resulting in heavy load on server side when dealing with a great amount of requests, thereby

the demand for something more efficient grew. In 1995-1996 the growth of web pages

increased dramatically and at the same time e-commerce got about. ColdFusion, PHP and

ASP (Active Server Pages) was created during the same period. Today ASP is replaced with

ASP.NET, but ColdFusion and PHP are still developed and used. The term "web application"

was first introduced in 1999 in the Servelet Specification version 2.2 for the Java language.

Today most web sites are interactive in some way which has made them more complex to

develop and the term web application has become generic.


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4.WHO SHOULD USE A FRAMEWORKDifferent frameworks might aim for different goals, but in general they all aim for

supporting developers in their work of creating an application with as little effort as possible

with as little hinder as possible. A framework can be used for many purposes, not only serve

common functionalities; it can also help learning a design pattern. Therefore new developers,

that knows some programming but do not know so much about design patterns and best

practice, can benefit from a framework by gaining understanding and programming skills. A

beginner will not feel that the framework is getting in the way as much as an experienced

developer. An experienced developer already knows the basics and how everything functions

and the various parts are related to each other and might therefore sees hinders instead of

possibilities. Experienced developers are also more likely work on more advanced projects

where a framework might not be suitable, due to the broad use of the application and greater

demand for high performance. The advantages of using a framework should be greater than

the disadvantages, otherwise it would, obviously, not be any point of using a framework.


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5.WEB FRAMEWORKS IN JAVACoding good-looking web applications in java is not super easy. It can be hard to do

and mostly doesnt give us the rich front-end we strive to deliver to happy users. This is

really the catalyst which has caused web frameworks to be created. Both, functional and non-

functional web app requirements have led to the need for various web frameworks to be

created.

The Spring MVC Framework is an open source application framework and inversion

of control container for the Java platform. In Spring Web MVC you can use any object as a

command or form-backing object; you do not need to implement a framework-specific

interface or base class. Java server faces is java specification for building component baseduser interfaces for web applications. It is a standardized display technology which was

formalized in a specification through the java community process. Apache Struts is an

elegant, extensible framework for creating enterprise-ready Java web applications. The

framework is designed to streamline the full development cycle, from building, to deploying,

to maintaining applications over time. GWT Web Toolkit is an open source set of tools that

allows web developers to create and maintain complex JavaScript front-end applications

in Java. Other than a few native libraries, everything is Java source that can be built on any

supported platform with the included GWT Ant build files. It is licensed under the Apache

License version. Play is an open source web application framework, written

in Scala and Java, which follows the modelviewcontroller (MVC) architectural pattern. It

aims to optimize developer productivity by using convention over configuration, hot code

reloading and display of errors in the browser. Play is a high-productivity Java and Scala web

application framework that integrates the components and APIs you need for modern web

application development.

Play is based on a lightweight, stateless, web-friendly architecture and features

predictable and minimal resource consumption (CPU, memory, threads) for highly-scalable

applications thanks to its reactive model, based on iterate IO.


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JIT compilation is a combination of the two traditional approaches to translation to

machine code ahead of time compilation (AOT), andinterpretation and combines some

advantages and drawbacks of both. Roughly, JIT compilation combines the speed of

compiled code with the flexibility of interpretation, with the overhead of an interpreter and

the additional overhead of compiling (not just interpreting). JIT compilation is a form

ofdynamic compilation, and allowsadaptive optimization such asdynamic recompilation

thus in principle JIT compilation can yield faster execution than static compilation.

Interpretation and JIT compilation are particularly suited fordynamic programming

languages, as the runtime system can handle late-bound data types and enforce security

guarantees.

The java development kit is a software development environment used for developingjava applications and applets. It includes the java runtime environment, an interpreter/loader,

a compiler, an archiver, a documentation generator and other tools needed in java

development.
http://en.wikipedia.org/wiki/AOT_compilerhttp://en.wikipedia.org/wiki/Interpreter_(computing)http://en.wikipedia.org/wiki/Dynamic_compilationhttp://en.wikipedia.org/wiki/Adaptive_optimizationhttp://en.wikipedia.org/wiki/Dynamic_recompilationhttp://en.wikipedia.org/wiki/Dynamic_programming_languagehttp://en.wikipedia.org/wiki/Dynamic_programming_languagehttp://en.wikipedia.org/wiki/Dynamic_programming_languagehttp://en.wikipedia.org/wiki/Dynamic_programming_languagehttp://en.wikipedia.org/wiki/Dynamic_recompilationhttp://en.wikipedia.org/wiki/Adaptive_optimizationhttp://en.wikipedia.org/wiki/Dynamic_compilationhttp://en.wikipedia.org/wiki/Interpreter_(computing)http://en.wikipedia.org/wiki/AOT_compiler


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7.COMPARING WEBFRAMEWORKWeb framework comparison across the following categories.

7.1 Rapid application prototyping

Whether youre using the framework for the first time, or youre an expert in all things

framework related, its important to be able to develop quickly to prototype an idea orjust try

new things out. This section rates each framework for the ability to produce content from

scratch with rapid results.

Spring MVCIf youre looking for a framework to help you generate an application fast and clean,

Spring really shouldnt be your go to. Its MASSIVE and hard to grasp if youre just starting

out. For a quick template, you can always download the Petclinic package and strip all of the

unnecessary stuff out but even that will take time, and you need to be able to tell what is

necessary.

Score: 2.5/5Much preexisting Spring knowledge is needed. Plain JSP & Controllers do not

provide out-of -the-box components and widgets that can be used

GrailsGrails comes with areloading mechanism out of the box, but it has some limitations and

you may still want to useJRebel if a part of your project is in Java. The setup is very fast and

scaffolding (code generation) saves a lot of time. Convention over configuration principle

helps you to forget almost all of the configuration hassle.

Score: 5/5 Top marks here. Scaffolding, conventions and hot code reloading, what else

could you want?

GWTThere are lots of pre-canned widgets for quick use but really anything you can do with

JavaScript and the browsers DOM can be done with GWT. If you prefer designing, you can
http://grails.org/Auto+Reloadinghttp://jrebel.com/http://jrebel.com/http://grails.org/Auto+Reloading


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also use GWTs built-in Design Mode, an easy drag and drop interface with automatic code

generation.

Its no Grails, but the goal is to allow developers to productively develop web apps

without being an expert in JavaScript, XMLHttpRequest, and various browser quirks.

Score: 4/5GWT is easy to create and maintain web apps widgets, and the built-in compiler

takes care of efficiency and browser support.

JSFJSF is not fantastic for quick prototyping; code generation is not a built-in feature and

prototype applications require just as much configuration as a full application. This is not

really JSFs fault, as it is reliant on the Java EE specification. JSF does have several useful

Maven archetypes, however, that do provide a good starting point for a basic application.

Prototyping can also be achieved with the vast array of sample projects available both online

and bundled with many of the Java EE application servers. The biggest gains to productivity

with JSF are the wizards available in most IDEs that generate most of the boilerplate code

and configuration for you.

Score: 3/5The quick prototyping of JSF relies on the tooling around it. Maven and

Netbeans provide archetypes and wizards to assist with getting started.

7.2 Framework Complexity

This section is where we explore each frameworks construction. Here, well discuss how

many moving parts exist in each framework and how the complexity of the framework affects

you. There are also other considerations when choosing frameworks, such as whether the

extra features and benefits outweigh the extra complexity levied against frameworks for your

application.

Spring MVCSpring is the Mount Everest, the Pacific Ocean, and the Stegodon of frameworks. The

base Spring framework gives a solid foundation for over 22 subprojects, which increases with

the scope of your application.


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available. There are open source implementations of the JSF specification that do allow the

use of non-Java EE containers like Tomcat, which cuts down tremendously on the complexity

of having to run a full Java Enterprise application server (there are middle grounds though,

like WebSpheres Liberty Profile). The complexity does come with the benefit of access to

the rest of the Java EE stack.

Score using JSF in a Java EE stack: 3.5/5When using the Java EE implementation of

JSF, we must account for the complexity of the Java EE specification and running a full Java

EE server, and one would be hard pressed to claim that the Java EE specification is not

complex.

Score using JSF in an OS implementation: 3/5When using an OS implementation ofJSF, we need to account for the complexity of the underlying framework that JSF is being run

on top of.

7.3 Ease of Use

This section is all about how easy it is to pick up a framework for the first time and play

with it, learn and get results. Think of it this way: if you gave one of these frameworks to a

colleague, how many questions would you have to answer for them? The quality of

documentation is always useful, but if you have to refer to the docs, have you already lost the

battle?

Spring MVCSpring is extensive to say the least and, as a result of that, is not particularly easy to just

pick up one day and use. In order to take advantage, you need to know how Spring as a whole

works, which is its biggest caveat. There are a lot of online tutorials and documentation pages

as well as the Petclinic sample application that you could strip down and use as a base, but,

overall, Spring is for building serious applications with solid foundations, rich user interfaces

and a RESTful API, which makes it completely unnecessary for anything significantly

simpler than that.

Score: 3/5Spring knowledge needed. Plain JSP & Controllers do not provide usable, out-of

-the-box components and widgets.


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GrailsGrails is designed to be a rapid development framework and rapid is a direct consequence

of ease of use. It is advocating convention over configuration and doing it right. Extensibility

is very simple when using plugins. One command in the console and all the dependencies

and configurations are managed for you.

One downside is that you need to get familiar with Groovy when you learn how to use

Grails. But it shouldnt be a big problem since Groovy is so Java-like anyway.

Score: 4.5/5Designed to be easy to use without any complex configuration, and Groovy

should be more or less easy for Java developers.

GWTWhether youre a coder or a designer, GWT has a good, fairly straightforward structure.

The component structure for the coders out there is easy to work with and the widget options

are numerous. The code is easy to read, modify and reuse, and if you are already familiar

with client-side storage that is easy to work with as well, the only problem is, theres so much

of it. The code is incredibly similar to JavaScript so if youd need to be familiar with it todevelop quickly.

GWT Designer, while not for everyone, is a powerful bi-directional Java GUI designer

that lets you create user interfaces with tools for intelligent layout assist, drag-and-drop, and

automatic code generation.

Score: 4/5Code is easy to read and write and theres a Design mode is there for the non-

coders. Client side storage is a little hard to grasp if you havent used it before.

JSFJSF tries to provide an easy to use framework for creating reusable web components in

your Java applications without a large learning curve. JSF 2.2 was recentlyratified and

released as part of the Java EE 7 specification. JSF is very easy to get up and running and

often does not require extra downloads or configuration as the necessary code is bundled in

any Java EE compliant application server.
http://www.jcp.org/en/jsr/detail?id=344http://www.jcp.org/en/jsr/detail?id=344http://www.jcp.org/en/jsr/detail?id=344http://www.jcp.org/en/jsr/detail?id=344


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Assuming its not enabled already, getting JSF support in your application server can be

as simple as enabling a checkbox. There are several great tutorials for JSF, some written

byOracle and others by third parties (MyFaces andothers).

JSF can be a little confusing at times however, Java EE can be overwhelming and

incredibly useful features can seem obtuse or obfuscated by poor documentation or easy to

miss in the corpus that is the body of Java EE features. Documentation for JSF is often

incredibly specific to certain tailored environments, and straying from the happy path often

leads to frustration and woe for hopeful and aspiring Java EE developers.

Score: 4/5JSFs tooling makes it easy to use and there are no external dependencies as long

as you stay within the Java EE ecosystem, which JSF leverages well. There are also several

built in components that provide tremendous benefit and some third party component

libraries that look great.
http://www.oracle.com/technetwork/java/javaee/documentation/index-137726.htmlhttp://myfaces.apache.org/docindex.htmlhttp://www.vogella.com/articles/JavaServerFaces/article.htmlhttp://www.vogella.com/articles/JavaServerFaces/article.htmlhttp://myfaces.apache.org/docindex.htmlhttp://www.oracle.com/technetwork/java/javaee/documentation/index-137726.html


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8. HOW TO CHOOSE A WEBFRAMEWORK

8.1 Software Pattern

Almost every framework out there exclusively uses the MVC pattern. MVC, whichstands for Model-View-Controller, helps you keep your data: the model, the logic: the

controller and the user interface: the view, separate from each other. Just because almost

everyone uses MVC doesnt mean that is everything you need to know though. There are a

couple of variants including MVP: Model-View-Presenter, MVA: Model-View-Adapter and

AVC: Application-View-Controller.

8.2 Hosting Requirements

As web developers, we may be inclined to building applications on cutting edgeplatforms but often the need and budget of the client comes first. Often it may be out of the

budget to get a dedicated host to place our applications on and well have to settle with

shared hosting with normal modules and settings.

8.3 Ease of Installation

Ease of installation plays a very important role whilst choosing a framework. A

framework, however feature laden or quick it may be, can pose quite a problem if one has to

run through a number of steps just to get it installed and working.

8.4 Learning Curve

Every framework has its own tiny universe: naming conventions, directory structure

and what notes. Some frameworks are rather flexible when it comes to these while others are

very, very strict throwing up errors at the tiniest of mistakes. Some frameworks follow

general conventions while implementing a feature while others may strike out and do its own

thing. While choosing a framework, remember to choose one that has the smallest possible

learning curve.

8.5 DB Abstraction and ORM

Almost every application has to access a database to either read data off or edit its

contents. So while choosing an application, choose one which lets your application become

database agnostic. Youll never have to care about the database part in case you need to

switch out databases if your framework takes care of that.The second part youll need to think

about is the frameworks ORM capabilities. Without getting technical, ORM or Object

Relational Mapping lets you express data as an object and see how it relates to other objects.


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10. JAVA SERVER FACES

Java server faces is java specification for building component based user interfacesfor web applications. It is a standardized display technology which was formalized in a

specification through the java community process.

10.1 JSF ARCHETECTURE

Fig.10.1 JSF Archetecture


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10.2 JSF LYFE CYCLE

The six phases show the order in which JSF processes a form. The list shows the

phases in their likely order of execution with event processing at each phase.

10.2.1 Restore view

JSF begins the restore view phase as soon as a link or a button is clicked and JSF

receives a request.

During this phase, the JSF builds the view, wires event handlers and validates to UI

components and saves the view in the Faces Context instance. The Faces Context instance

will now contains all the information required to process a request.

10.2.2 Apply request values

After the component tree is created/restored, each component in component tree uses

decodes method to extract its new value from the request parameters. Component stores this

value. If the conversion fails, an error message is generated and queued on Faces Context.

This message will be displayed during the render response phase, along with any validation

errors.

If any decode methods / event listeners called render Response on the current Faces

Context instance, the JSF moves to the render response phase.

10.2.3 Process validation

During this phase, the JSF processes all validators registered on component tree. It

examines the component attribute rules for the validation and compares these rules to the

local value stored for the component.

If the local value is invalid, the JSF adds an error message to the FacesContext

instance, and the life cycle advances to the render response phase and display the same page

again with the error message.


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10.2.4 Update model values

After the JSF checks that the data is valid, it walks over the component tree and set

the corresponding server-side object properties to the components' local values. The JSF will

update the bean properties corresponding to input component's value attribute.

If any update Models methods called render Response on the current FacesContext

instance, the JSF moves to the render response phase.

10.2.5 Invoke application

During this phase, the JSF handles any application-level events, such as submitting a

form / linking to another page.

10.2.6 Render response

During this phase, the JSF asks container/application server to render the page if the

application is using JSP pages. For initial request, the components represented on the page

will be added to the component tree as the JSP container executes the page. If this is not an

initial request, the component tree is already built so components need not to be added again.

In either case, the components will render themselves as the JSP container/Application server

traverses the tags in the page.

After the content of the view is rendered, the response state is saved so that subsequent

requests can access it and it is available to the restore view phase.


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11. JSF USER INTERFACE COMPONENT MODEL

11.1 JSF EVENT HANDLING

When a user clicks a JSF button or link or changes any value in text field, JSF UI

component fires event which will be handled by the application code. To handle such

event, event handlers are to be registered in the application code or managed bean. When

a UI component checks that a user event has happened, it creates an instance of the

corresponding event class and adds it to an event list. Then, Component fires the event,

i.e., checks the list of listeners for that event and call the event notification method on

each listener or handler. JSF also provide system level event handlers which can be used

to do some tasks when application start or are stopping.

11.2 JSF CONVERTER TAGS

JSF provides inbuilt convertors to convert its UI component's data to object used in a

managed bean and vice versa. For example, these tags can convert a text into date object

and can validate the format of input as well.

f:convertNumberConverts a string into a Number of desired formats.

f:convertDateTimeConverts a string into a Date of desired format.

costomConverterCreating a custom converter.

11.3 JSF VALIDATION TAGS

JSF provides inbuilt validators to validate its UI components. These tags can validates

length of field, type of input which can be a custom object.

f:validationLength- validates length of a string.

f:validateLongRange- validates range of numeric value.

f:validateDoubleRange- validates range of float value.

f:validateRegex- validates JSF component with a given regular expression.

CustomValidator- creating a custom validator.


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11.4 JSF PAGE NAVIGATION

Navigation rules are those rules provided by JSF Framework which describe which

view is to be shown when a button or link is clicked. Navigation rules can be defined in

JSF configuration file named faces-config.xml. Navigation rules can be defined in

managed beans. Navigation rules can contain conditions based on which resulted view

can be shown. JSF 2.0 provides implicit navigation as well in which there is no need to

define navigation rules as such.


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12.CONCLUSIONWe live in exciting times to be building websites; we liken using web frameworks in web

development to the industrial revolution in manufacturing. Earlier it was very hard to develop

a complex web applications. The main purpose of web application framework is to support

the development of dynamic websites, web applications, web services, and web resources and

it also helps the programmers to build the application quickly.

As a developer using a framework, you typically write code which conforms to some kind

of conventions that lets you plug in to the framework, delegating responsibility for thecommunications, infrastructure and low-level stuff to the framework while concentrating on

the logic of the application in your own code.


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13.RFERENCES

Books/Articles

Ed Burns and Chris Schalk Java Server Faces Robert Skoczylas Developing Java Web Services Criag Knuckles and David Yuen Web Applications

Web Links

Wikipedia 15 December 2014

Java symposium< http://javasymposium.techtarget.com/html/frameworks.html#GMaggessyJSF > 20

December 2014

Rose India 28 December 2014

Zero turned around 05 January 2014
http://en.wikipedia.org/wiki/Web_application_frameworkhttp://javasymposium.techtarget.com/html/frameworks.htmlhttp://www.roseindia.net/jsf/index.shtmlhttp://zeroturnaround.com/rebellabs/the-2014-decision-makers-guide-to-java-web-frameworks/2/http://zeroturnaround.com/rebellabs/the-2014-decision-makers-guide-to-java-web-frameworks/2/http://zeroturnaround.com/rebellabs/the-2014-decision-makers-guide-to-java-web-frameworks/2/http://zeroturnaround.com/rebellabs/the-2014-decision-makers-guide-to-java-web-frameworks/2/http://www.roseindia.net/jsf/index.shtmlhttp://javasymposium.techtarget.com/html/frameworks.htmlhttp://en.wikipedia.org/wiki/Web_application_framework

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