WebServices Notes by Sekhar Sir JavabynataraJ

Web Services

~- ~ ~.~ -- .. . . ...

WEB-SERVICES [Intro) By Mr. SekharReddy ., i ; Q.) What is distributed technology?

I ' I

A technology is said to be distributed i f it's business objects are geographically dispersed i I (across multiple JVM's) and st111 communicating one another. ' 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 CORBA o RMI o EJB o WEB SERVICES ... etc.

.&

CORBA > More complexity in the implementation

I - > Heavy weight Language dependent

I > Commercial I :, Plat from independent

RMI I > Lack of Enterprise services/Middle ware services I > Open source I IVo acknowledgement , # I > Language dependent I > Plat from independent

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 I

. . . . . . . . . . . . . . . . . . .- - . . . . .. . . -, . . . - - . . - . - - - .- . . .. . .- - - - -- . . - - - .- .- . . . .

Page 1 -

http://javabynataraj.blogspot.com 2

. . - ~ - ~ .. - - ...p-p.p....p-.pp-

WEB-SERVICES (Intro) By Mr. ~ e k h a r ~ e d d v ~ ~ . ~ ~ ! I > Managed by Application server

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

WEB SERVICES I-? Supports Enterprise services I > Interoperable (Language independent & Plat from independent)

So, Web services is interoperable distributed technology I ! 1

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

1 .) Two persons @ I I 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 Both application needs to communicate by following some rules(protocols)

o H r r P o FTP o SMTP ... etc.

r:, To communicate language is required(Neutra1 language) o XML

- --

~ a G s h i Technologies, Opp. Satyam Theatre, Arneerpet, Hyderabad, Ph: 040-23746666,23734842 . . . . . . . . . . -. . - - - - - - -

An I S 0 9001 : 2000 Certified Company P~@Z---


- -. --ppp-p..-- --

WEB-SERVICES (Introl Bv Mr. ~ e k h a r ~ F d x F T I 1

SMTP

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

X I

I > Lets assume that we are sending employee information form "Consumer" to "Provider" in the XML format as follows. i

I

ysreddy +.-..- - __.__.L.---'

Authentication Data * * * * * *

,,,'

,.,;,- Authentication Data ,,,,,, ,,.. ,,, ,,'

,,I'

,.,.,'' ,,.,

ysreddy:::-. . ,, ,,,... ,,,, ,,,,, I, ,111 ..__> ,,,, , 1

,,,' ,,,"

**** **

.- ~~ - ~ - - -

WEB-SERVICES (Intro) Bv Mr. SekharReddv-- 1

.;t, "WSDL" is the document which explains the services information. But how can I "Consumer" get that WSDL document, from where "Consumer" get? i

L-:, So "WSDL" documents has to be placed in some location from where "Consumer" can access them, that location is nothing but "UDDI"

I I

~2 UDDI stands for Universal Description Discovery and Integration I UDDI is the Registry where all the WSDL documents are registered ' I , ' I UDDI should be interoperable, so it is also developed in XPIL \ I r2 UDDI registry also called XlYL registry I

-

I

i i ~.

Naresh i Technologies, Opp. Satyam Theatre, Ari~eerpet, Hyderabad, Ph: 040-23746666,23734842 An IS0 9001 : 2000 Certified Company 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 to 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- http://javabynataraj.blogspot.com 7

, - - - ~

WEB-SERVICES (Intro) By Mr. S e k h a r R e d d v . ,

I Q.) What are Web services? I

I-:, Web services is a software application that confirms the WS-1's given speicifiations( BP -.I

l.O/BP l . l / B P 2.0) is said t o be web services. I I I I 13 Any program that is distributed in nature, language independent and plat form neutral is \ said to be web services.

I I -

I I There so many API's, Implementations for the 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

JAX-RPC -4 ,AX-ws I

JAX-RPC : Java APIs for XML-based Remote Procedure Call

JAX-WS : Java API fo r XPlL Web Services

JAX-P : Java API for XML Processing

JAX-B : Java Architecture for XML Binding I i -

JAX-R : Java API for XML Registries 1 SAAJ : SOAP with Attachments API for Java 1

.-

1 Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 I

I . - . -. . - - - -. -. . --

An IS0 9001 : 2000 Certified Company p a g e - 7 -

Implementation (from different companies)

-- -- . -- --

Specification (froni WS-I)

API (from Sun microsystem)


. . . . ~

. WEB-SERVICES [Intro) By Mr. ~ekharkeddf

JAX-WS RI(from Sun) BP 1.1 JAX-WS Apache-Axis2(from ASF)

Metro(from Sun) CXF(from ASF) ... etc.

- - - -- - -- - -- - - pp -

BP 1.0

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

i i NOTE: Apache CXF internally uses spring.

- --

JAX-RPC

! Web Services Development

-- ----

JAX-RPC-SI(from sun) ... Apache-Axis(from ASF) etc

I I Web services development can done in two ways

1. Contract first(top-down) approach 2. Contract last(bottom-up) approach

-

I , Contract first A ~ ~ r o a c h -

! WSDL + Services ! - I

Contract last Amroach 1 I

I ' Services + WSDL I 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.. ... I ~3 I n java, Services can be developed using any implementations like sun, apache etc..

I I But WSDL development is unique, it's not plat form specific, not language specific, not technology specific, not API specific, not implementation specific.

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

I I 3 JAX-RPC , Contract last approach I I

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

/ which supports HlTP protocol. - I ! Q.) What are the HTTP protocols implemented API's? ( 1. Servlet API

2. EJB API i I I

Naresh i Technologies, opp. Satyarn Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842 1 I 1 An IS0 9001 : 2000 Certified Company

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

I Pa ge8--. , http://javabynataraj.blogspot.com 9

--- --

WEB-SERVICES (lntro'l--- Bv Mr. ~ e k h a r ~ e d T l t 7

' Q.) W h a t is e n d p o i n t ? 1 I, A component which receives "Consumer" request

I, I n general we use either servlet or ejb as an End Po~nt. So, we can say we are developing web services using

I > JAX-RPC, Servlet end point url, Contract first approach 1 > JAX-RPC, EJB end point url, Contract last approach

I

i MEP 1 MEP stands for ~ e s s a g d ~ x c h a n g i n g Patterns

1

r3 " C o n s ~ ~ r n e r ~ ~ can communicate with "Provider" in three ways o Synchronous request-reply o Asynchronous request-reply

I I o Fire and forget

I I Synchronous reques t - rep ly I 0 I n this "Consumer" sends the request t o "Provider", and "Consumer" blocks until response I

comes back from the "Provider", Until response comes back "Consumer" can't proceed. I

After Response Received, continues i ts process ......

Asvnch ronous reauest-re~ly 1 I I

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

I > After request sent t o the "Provider" it continues its flow of execution I "Consumer" will have "Response L is tener " which listens the response from the

"Provider". - i

I Naresh i Technologies, Opp. Satyam Theatre, Ameerpet, Hyderabad, Ph: 040-23746666,23734842

An I S 0 9001 : 2000 Certified Company i - - - - -

I .-,

Page 9 http://javabynataraj.blogspot.com 10

WebServices Notes by Sekhar Sir JavabynataraJ

Documents

Transcript of WebServices Notes by Sekhar Sir JavabynataraJ