WebServices Complete Notes-JavaEra.com

JavaEra.com A Perfect Place for All Java Resources

Core Java | Servlet | JSP | JDBC | Struts | Hibernate | Spring Java Projects | FAQ’s | Interview Questions | Sample Programs Certification Stuff | eBooks | Interview Tips | Forums | Java Discussions

For More Java Stuff Visit

www.JavaEra.com A Perfect Place for All Java Resources

Hi Friends! Welcome to JavaEra.com. As an admin,, let me introduce myself to all of you. I am Anil

Reddy from Hyderabad. I’m a normal guy who lives life to

the fullest, loves programming and lives a happy-go-lucky lucky kind of life. Why I started JavaEra.com? JavaEra.com I was a job seeker like you all but I was not sure about how to attempt an interview or various companies selection process. I had searched many Portals on the web & joined many job groups. From all those sources I was getting the information regarding latest job openings only but not any resources to chase job selection process by improving my skills. Why we need those skills? Just go through this small story... Once upon a time a very strong woodcutter asks for a job in a timber merchant, and he got it. The paid was really good and so were the work conditions. For that reason, the woodcutter was determined to do his best. His boss gave him an axe and showed him the t area where he was supposed to work. The first day, the woodcutter brought 18 trees "Congratulations," the boss said. "Go on that way!" Very motivated for the boss' words, the woodcutter try harder the next day, but he only could bring 15 trees. The third thir day he try even harder, but he only could bring 10 trees. Day after day he was bringing less and less trees. "I must be losing my strength", the woodcutter thought. He went to the boss and apologized, saying that he could not understand what was going on. on "When was the last time you sharpened your axe?" the boss asked. "Sharpen? I had no time to sharpen my axe. I have been very busy trying to cut trees.

If we are just busy in applying for jobs, when we will sharpen our skills to chase the job selection process? p I don’t have many friends who can suggest me or who can share some tips. I got irritated like anything. I thought that like me, there may be millions of my brothers and sisters across the nation facing same kind of problem. So I strongly committed to start a special zone for all job seekers & IT professionals where everyone can sharpen their skills to find their dream job & in their dream company. As a result in 10 months nearly 15000+ job seekers joined our family. Thousands of people got benefited by utilizing our resources. This is just a start, what we have achieved till now is just 0.1% in our vision which is “Creating a perfect place to share Java knowledge”. Now I am not alone in chasing this challenge. We will work together by sharing knowledge knowle & giving a ray of hope to millions of our brothers and sisters across the nation. My Technical Skills: Google SEO (Search Engine Optimization) Certified. JSE (Certified), Servlets, JSP, Struts, Hibernate, Spring, PHP, Zend Framework. HTML, JavaScript, Jquery, AJAX, CSS, Adobe Photoshop Photoshop CS6, Adobe Illustrator CS5, CS5 Adobe Flash. My aim is to provide good and quality articles and content to readers and visitors to understand easily. All articlesare written and practically tested by me before publishing online. ine. If you have any query or questions regarding any article feel free to leave a comment or You ou can get in touch with me On [email protected], www.facebook.com w.facebook.com/JavaAnil

Regards Anil Reddy Founder & Administrator JavaEra.com Email : [email protected] [email protected], [email protected]. www.facebook.com/JavaAnil /JavaAnil

WebServices www.JavaEra.com

~-

WEB-SERVICES [Intro)

~

--

~.~

.. .....

By Mr. SekharReddy i; . ,

Q.) What is distributed technology? I

'

A technology is said t o be distributed if it's business objects are geographically dispersed (across multiple JVM's) and st111communicating one another.

I

i

I

'I

Q.) Why distributed technology? I-)

Load balancing

I

High Availability

I-:,

High Processing

Q.) What are different distributed technologies?

I

> There are so many distributed technologies o

o o o

CORBA RMI EJB WEB SERVICES ...etc. .&

CORBA > More complexity in t h e implementation I-> Heavy weight Language dependent > Commercial :, Plat from independent I

I

RMI > Lack of Enterprise services/Middle ware services I

Open source IVo acknowledgement > Language dependent > Plat from independent

I > I I

I

,#

E3 B I->

Supports Enterprise services/Middle ware services in the declarative manner Having multiple flavors of APIs t o handle different requirements o Session beans Stateless Stateful o Entity beans(not using now) = JPA o Message Driven Beans

--

!

.. ..

.. .. .

.

Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 An IS0 9001 : 2000 Certified Company - .-.. . . ... ...- - ........ ... - - . .- .- - -.-.... ..- - - - -- ..-,

Page 1

I

.. . .

-

..

-

-

~

~

.

-

-

. . . p p . p . . . . p . p p -

WEB-SERVICES (Intro) I

By Mr. ~ e k h a r ~ e d d v

> Managed by Application server

Robust Heavy weight c> Language Dependent G Plat from independent I

WEB SERVICES

Supports Enterprise services > Interoperable (Language independent & Plat from independent)

I-? I

So, Web services is interoperable distributed technology

I

!

1

Q.) What we require if two persons need to communicate?

I I

1 .) Two persons @ 2.) Medium 3.) Language 4.) RuIes(protocoI)

I

Web services architecture I f two applications needs to communicate

a Both the applications should be connected (network)

e

r:,

Both application needs to communicate by following some rules(protocols) o HrrP o FTP o SMTP...etc. To communicate language is required(Neutra1 language) o XML

-

--

~ a G s ihTechnologies, Opp. Satyam Theatre, Arneerpet, Hyderabad, Ph: 040-23746666,23734842 An I S 0 9001 : 2000 Certified Company .... .. . .. .-. .-- -- ---

P~@Z---

- -.

1

--

--ppp-p..--

WEB-SERVICES (Introl

Bv Mr. ~ e k h a r ~ F d x F T

SMTP

I n the internet world we prefer t o use H-TTP protocol, and we have so many technologies which supports HlTP protocol. I

> Lets assume that we are sending employee information form "Consumer" to "Provider" in

,,

I I

XI

i

the XML format as follows.

I

ysreddy+.-..** * * * *88@8
__.__.L.---'

Authentication Data

---_

sekhars--..------.-.-.-..- ----

'---:..___.----- -__._---

~

-Business Data

2489c---,-:--p------

e At "Provider" side it may be interpreted as follows

H

I

---,-

Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666 23734842 An I S 0 9001 : 2000 Certified Company

---- - -.-

-.

-

--

I I Page 3

-,;,., Authentication Data ,,.. ,,,,,' ,.,.,'' ,., ,,,... ysreddy:::-. . ,,," ******88688 : . " ~ekha~: : a , BusinessData ....... .. ............... .... " ........................ 2489 ,,,'

,,,,,,

,,I'

,,,,, ,,,,

I, , 1 1 1

,,

..__>

,,,,

,,,'

,1

'-I

...

' I .

. . . .

z-,



,I:

So, classification of the information is missing.

I-> So, we don't send raw XML document(contains business data) t o the providers.

I

I

I I

I

I

-

We need classification of the request data like o Processing information/Authentication information o Business inforniation I-:, To achieve this we will go for SOAP 0 SOAP stands for Simple Object Access Protocol SOAP is a classification protocol SOAP is a binding protocol(processing data + business data)

I->

C'onsu msr

Provider

But what services are providing by the Provider should be explained. To know the services of "Provider", "Consumer" cannot look into the code of of "Provider". 3 So "Consumer" needs the information like what are the services are providing, what they will take as input, and what t h e output they will return, what url has t o call t o get services ...etc. ~3 "Provider1' will explain all these information in one document called "WSDL". Q "WSDL" stands for Web Service Description Language + "WSDL" is an XML document, because it should be language independent, so that any type of client can understand the services of the "Provider".

..-.-.

-..-...........

Nares'h i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,.23734842 An IS0 9001 : 2000 Certified Company . . -........... -- .- ....... -. -

Page 4---

.-

~~

WEB-SERVICES (Intro)

-

~ - --

Bv Mr. SekharReddv-- 1

"WSDL" is the document which explains the services information. But how can "Consumer" get that WSDL document, from where "Consumer" get? So "WSDL" documents has t o be placed in some location from where "Consumer" can access them, that location is nothing but "UDDI" ~2 UDDI stands for Universal Description Discovery and Integration UDDI is the Registry where all the WSDL documents are registered UDDI should be interoperable, so it is also developed in XPIL r2 UDDI registry also called XlYL registry

I

.;t,

i

I

L,:-

I

I

'

I

, '

I

\

I

I

-

I

i

~

.

Naresh i Technologies, Opp. Satyam Theatre, Ari~eerpet,Hyderabad, Ph: 040-23746666,23734842 An I S 0 9001 : 2000 Certified Company

~.

i

I

i

- -..-

Page 5

' -

2 . ) What is WS-I? The WS-I (Web Services Interoperability) Organization is an association of I T industry compa~iies,including IBM and Microsoft, that aim t o create Web services specifications that all companies can use.

4.)What are the different standards given by WS-I to implement Web services ? r3

WS-I has given o Basic Profile 1.0 (BP 1.0) o Basic Profile 1.1(BP 1.l) o Basic Profile 2.0 (BP 2.0) Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 An I S 0 9001 : 2000 Certified Company . -- - - -- -

Pa=-6-

,

-

-

-

~

WEB-SERVICES (Intro)

By Mr. S e k h a r R e d d v .

Q.)What are Web services?

I

Web services is a software application that confirms the WS-1's given speicifiations( BP l.O/BP l . l / B P 2.0) is said t o be web services. 13 Any program that is distributed in nature, language independent and plat form neutral is said to be web services. I-:,

I

I

I I

,

I

-.I I

I

I \

-

There so many API's, Implementations for t h e WS-I given standards

1

~3

Sun has released "JAX-RPC" API that follows BP 1.0 standard Sun has released "JAX-WS" API that follows BP 1 . 1 standard

-4

JAX-RPC

,AX-ws

I

JAX-RPC : Java APIs for XML-based Remote Procedure Call JAX-WS : Java API f o r XPlL Web Services JAX-P : Java API for XML Processing JAX-B : Java Architecture for XML Binding

Ii

JAX-R : Java API f o r XML Registries

1

SAAJ : SOAP with Attachments API for Java

1

-

--

-- .

Specification (froni WS-I)

--

--

Implementation API (from Sun microsystem) (from different companies)

1

.-

.- .-. .- - -

Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 An IS0 9001 :2000 Certified Company

-.-..--

I

I

p a g e - 7-

.

. . .

~

. WEB-SERVICES [Intro) -- -- - --

-

BP

- -- - -

By Mr. ~ e k h a r k e d d f ------

-- --

p p

1.0

JAX-RPC

JAX-WS

BP 1.1

JAX-RPC-SI(from sun) Apache-Axis(from ASF) ...etc JAX-WS RI(from Sun) Apache-Axis2(from ASF) Metro(from Sun) CXF(from ASF) ...etc.

NOTE: JAX-WS RI(Reference Implementation) was fa~ledto access by .Net, means fa~ledin interoperability. Sun then released "metro" implementation of JAX-WS, which resolved interoperab~lityproblem and also added some more features. i

i

NOTE: Apache CXF internally uses spring.

!

Web Services Development

I

Web services development can done in two ways 1. Contract first(top-down) approach 2. Contract last(bottom-up) approach

I

-

,

I

Contract first A ~ ~ r o a c h

-

!!

WSDL -

+ Services

1

I

Contract last Amroach I

Services

'

I

I

+ WSDL

I

'

NOTE: ~3 Services can be developed with any technology like .Net, Java, Php ...etc d I n java, Services can be developed using any API like JAX-RPC, JAX-WS, RESTFUL...etc.. ~3 I n java, Services can be developed using any implementations like sun, apache ...etc.. I But WSDL development is unique, it's not plat form specific, n o t language specific, n o t technology specific, not API specific, not implementation specific.

,

I

I

So, we can say we are developing web services using I> JAX-RPC, Contract first approach 3 JAX-RPC , Contract last approach

,

I

I I

I

/ -

NOTE: I n the internet world w& prefer to use HlTP protocol, and we have so many technologies which supports HlTP protocol.

!

Q.) What are the HTTP protocols implemented API's?

I

(

1

I

1. Servlet API 2. EJB API

i

I

Naresh i Technologies, opp.Satyarn Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 An IS0 9001 : 2000-. Certified Company ......................... .-....... --

II Page8--.

I1 I ,

---

--

Bv Mr. ~ e k h a r ~ e d T l t 7

WEB-SERVICES (lntro'l--'

Q.) W h a t i s e n d p o i n t ? 1

I, I,

A component which receives "Consumer" request I n general we use either servlet or ejb as an End Po~nt.

So, we can say we are developing web services using > JAX-RPC, Servlet end point url, Contract first approach > JAX-RPC, EJB end point url, Contract last approach I 1

I

i MEP 1 1

r3

I I

I I

MEP stands for ~ e s s a g d ~ x c h a n g i nPatterns g " C o n s ~ ~ r n can e r ~ ~communicate with "Provider" in three ways o Synchronous request-reply o Asynchronous request-reply o Fire and forget

I

Synchronous request-reply 0 I n this "Consumer" sends the request t o "Provider", and "Consumer" blocks until response comes back from the "Provider", Until response comes back "Consumer" can't proceed.

I

I

After Response Received, c o n t i n u e s i t s process

......

1

A s v n c h r o n o u s reauest-re~ly

I

'I

e In this "Consumer" sends the.request t o "Provider", and "Consumer" will not wait until it I > I

-

--

gets the response. After request sent t o the "Provider" it continues its flow of execution "Consumer" will have " R e s p o n s e L i s t e n e r " which listens t h e response from the "Provider".

I

i

-

I

Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 An I S 0 9001 : 2000 Certified Company -

-

i

.-,

Page 9

I

I would try to update our site JavaEra.com everyday with various interesting facts, scenarios and interview questions. Keep visiting regularly.....

Thanks and I wish all the readers all the best in the interviews.

www.JavaEra.com A Perfect Place for All Java Resources