Web Services & SOAP Protocol Sravan Kumar Ananthula.

Web Services & SOAP Web Services & SOAP ProtocolProtocol

Sravan Kumar Ananthula

Advanced Protocols 2004


Motivation

• Exchanging data over Networks

– WebServices • Network Services provided over http –”Wired

Services”• A New way to build Network Applications

from distributed components that are language and platform independent

– SOAP• Simple,flexible and highly extensible • It is a Network Application Protocol


My Intrest in this protocol

• Enterprise Application Server – Weblogic Server (BEA) –past 2 yrs– .Net Frame Work (Microsoft)- past 6 months– Websphere (IBM)- Idea

• I used XML in these applications and latest techniques WSDL or SOAP consist some knowledge gaps.– Gaps: WSDL and SOAP reusability

functions.


Presentation Overview • Histroy• WebServices

– Software Components– Protocol Stack– Implementation

• Pros & Cons (Corba Vs Webservices)• SOAP

– SOAP Messages With out Attachments– SOAP Request / Response– SOAP Messages with Attachments– Data Types– Apache Installation and Usage in Apache– Sysitnet Implementaion

• Summary• References


History

Communication protocol over WWW – http-s (Over a Secure Socket) 443(port)

– 1991 http(V0.9) Tim Brener’s& Lee – 1996 http 1.0– 1999 http 1.1 (80:Port)

– XML – V1.0 Feb 10 1998 project of W3C

– SOAP – May 2000 – Dave Winner,Don Box and Bob Atkinson

» Microsoft & IBM filed to W3C» Later on all major Companies are approved» SOAP 1.1/SOAP 1.2


WebServices

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•New bread Web application•Self-contained,self-describing,

Modular applications that can be Published, located and invoked across the web ~~IBM Web service tutorial


Webservice Software Components

• A Webservice is a message-based network service

• A server which provides a web service must be capable of “sending and receiving messages using some combination of standard Internet protocols”

Service Provider

Service Broker Service Requestor

”Server”

”Naming Service” ”client”

Service Provider

Service Broker Service Requestor

”Server”

Publish(WSDL)Bind(SOAP)

Find(UDDI)

•SOAP & WSDL- W3 Standards•UDDI – OASIS Standard


Just-in-time Integration• Network services can be integrated

dynamically, on an as-needed basis.

• SunMicro’s jini is a framework that supports the idea.

• Network services are registered with a service registry; a service consumer/client looks up the registry to fulfill its needs.

• The binding of a client to the service can occur at runtime.

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WebService Protocol Stack &Protocols

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UDDI(Universal Description, discorvery And Integration )

WSDL(Web Service Defination Language)

XML,SOAP

TCP,HTTP,SMTP,FTP

IP


Basic webservice Usage Scenario

(manual)web Service Lookup

Reads ParametersFunctions

Write clientApplication

Webservice Repository

(UDDI)

Web Service Provider

Publish web Service

1 Register WSDLfile(manually)

2 http Get

3 WSDL file

4 SOAP Req

5 SOAP Resp


Web Services Implementation

HttpServer

SoapServer

Applicationserver

Web Service Provider

Requestor

Soap Client

Soap Messages(http transport)

• Application Server (Web service-enabled)

Provides implementation of services and exposes it through WSDL/SOAP

implementation in Java,J2EE,.Net(C#)

•Soap Server – implements Soap Protocol

•Http Server - Standard web server

•Soap Client – implements Soap Protocol on client Site


Corba Vs Webservices (1/2)

CORBA STACK WEB SERVICES STACK

IDL WSDL

CORBA(Naming Services) UDDI

CORBA (Stub/Skelton) SOAP Messaging

CDR binary encoding XML Unicode encoding

GIOP/IIOP HTTP

TCP/IP TCP/IP

~Both technologies lies on TCP/IP~Deviate at Transport Layer where webservice choose web protocol and CORBA is proprietary to standard


Corba Vs WebServices (2/2)Feature Object Model Web Service

Data Model Object Model SOAP message exchange model

Client-Server Computing

Tight Coupling(Common State)

Loose Coupling

Type System IDL XML

Location Transperancy

Object References URL

Parameter Passing By reference /Value By Value Only

Type Checking Static+ runtime Runtime only

Service Discovery Naming /Trading Service

UDDI

Serialization Built on ORB Choosen by user


SOAP (Simple Object Access Protocol)

• SOAP is a protocol which applies XML for message exchange in support of remote method calls over the Internet.

• Light Weight messaging framework based on XML

• Supports simple messaging and RPC• Platform independent and language

independent


Remote Procedure Call using Http

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SOAP Messages

Soap Message Object with No Attachments

SOAP Message

Envelope: top element of XML message

Header: General Information on message such as security

Body: data exchanged

Fault : Error messages

http://www.w3.org/2001/12/soap-envelope


An XML –encoded SOAP RPC<?xml version="1.0"?> <soap:Envelope

xmlns:soap="http://www.w3.org/2001/12/soap-envelope" soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Header> ...Headers here ...

</soap:Header><soap:Body> <soap:Fault>

... ...Request goes here... ... </soap:Fault> </soap:Body></soap:Envelope>

Name Space

Encoding Style


Example of a SOAP Message


SOAP Header Element• <?xml version="1.0"?> <soap:Envelope

xmlns:soap="http://www.w3.org/2001/12/soap-envelope" soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding"><soap:Header>

<m:Trans xmlns:m="http://www.w3schools.com/transaction/" soap:mustUnderstand="1">234

</m:Trans> </soap:Header>... ...</soap:Envelope> Two Attributes : Actor

Must Understand


Example on SOAP Header Element

• <?xml version="1.0"?> <soap:Envelope xmlns:soap="http://www.w3.org/2001/12/soap-envelope" soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding"><soap:Header>

<m:Trans xmlns:m=http://www.w3schools.com/transaction/

soap:actor=http://www.w3schools.com/appml/

soap:mustUnderstand="1"> > 234 </m:Trans>

</soap:Header> ... ...</soap:Envelope>

URI After transaction

True/False


A SOAP Message that contains a RPC

• <?xml version="1.0"?> <soap:Envelope

xmlns:soap="http://www.w3.org/2001/12/soap-envelope" soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body> <m:GetPrice

xmlns:m="http://www.w3schools.com/prices"> <m:Item>Apples</m:Item>

</m:GetPrice> </soap:Body></soap:Envelope>

Source at (W3schools.com)

Procedure Name

Server NameParameters


Example of a SOAP Request• <?xml version="1.0" encoding="UTF-8"

standalone="yes"?><e:Envelope

xmlns:d="http://www.w3.org/2001/XMLSchema" xmlns:e="http://schemas.xmlsoap.org/soap/envelope/" xmlns:i="http://www.w3.org/2001/XMLSchema-

instance" xmlns:wn0="http://systinet.com/xsd/SchemaTypes/"

xmlns:wn1="http://idoox.com/interface"> <e:Body> <wn0:p0 i:type="d:string">world</wn0:p0> </e:Body></e:Envelope> Parameter of type String and value world


Response Example• <?xml version="1.0" encoding="UTF-8"

standalone="yes"?> <e:Envelope

xmlns:d="http://www.w3.org/2001/XMLSchema"

xmlns:e="http://schemas.xmlsoap.org/soap/envelope/" xmlns:i="http://www.w3.org/2001/XMLSchema-

instance" xmlns:wn0="http://systinet.com/xsd/SchemaTypes/"

xmlns:wn1="http://idoox.com/interface"> <e:Body> <wn0:string_Response i:type="d:string">Hello,

world!</wn0:string_Response> </e:Body></e:Envelope>

Returned ValueType of Value


Example of Error RPC Response

• <?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<e:Envelope xmlns:d="http://www.w3.org/2001/XMLSchema"

xmlns:e="http://schemas.xmlsoap.org/soap/envelope/" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:wn0="http://systinet.com/xsd/SchemaTypes/"

xmlns:wn1="http://idoox.com/interface">

<e:Body> <e:fault> <wn0:fault_code>e:Server</wn0:fault_code> <wn0:string_Fault i:type="d:string">Service is not Exist</wn0:string_Fault> </e:fault> </e:Body></e:Envelope>

Version Mismatch/Client/Server/MustUnderstood


Http and SOAP RPC Request

• A SOAP message can be used to transport a SOAP remote procedure request /response as follows:

POST /demo/basic/HelloService HTTP/1.0User-Agent: Systinet WASP Server for Java/5.0 (Java/1.5.0;

Windows XP/5.1)Host: 130.226.31.142:6060Connection: closeProxy-Connection: closeSOAPAction: ”Url/examples”<blankline><text for SOAP message>


An Http Request carries a SOAP RPC request

POST /demo/basic/HelloService HTTP/1.0User-Agent: Systinet WASP Server for Java/5.0 (Java/1.5.0; Windows

XP/5.1)Host: 130.226.31.142:6060Connection: closeProxy-Connection: closeSOAPAction:"http://systinet.com/wsdl/demo/basic/hello/server/

HelloService#hello?KExqYXZhL2xhbmcvU3RyaW5nOylMamF2YS9sYW5nL1N0cmluZzs="

Content-type: text/xml;charset=UTF-8X-WASP-Message-ID: 11e-FLxtbx/tDgWbei5OeHEwbw==Content-length: 356<?xml version="1.0" encoding="UTF-8"?><e:Envelope xmlns:e="http://schemas.xmlsoap.org/soap/envelope/"

xmlns:d="http://www.w3.org/2001/XMLSchema" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:wn0="http://systinet.com/xsd/SchemaTypes/" xmlns:wn1="http://idoox.com/interface"><e:Body><wn0:p0 i:type="d:string">world</wn0:p0></e:Body></e:Envelope>

SOAP

Action

Length of text


An Http Request that carries a SOAP Response

HTTP/1.0 200 OKDate: Sun, 21 Nov 2004 14:55:57 GMTConnection: closeServer: Systinet WASP Server for Java/5.0 (Java/1.5.0; Windows

XP/5.1)SOAPAction: ""Content-type: text/xml;charset=UTF-8X-WASP-Message-ID: 11e-FLxtbx/tDgWbei5OeHEwbw==

<?xml version="1.0" encoding="UTF-8"?><e:Envelope

xmlns:e="http://schemas.xmlsoap.org/soap/envelope/" xmlns:d="http://www.w3.org/2001/XMLSchema" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:wn0="http://systinet.com/xsd/SchemaTypes/" xmlns:wn1="http://idoox.com/interface"><e:Body><wn0:string_Response i:type="d:string">Hello, world!</wn0:string_Response></e:Body></e:Envelope>

SOAP Resp

Returned Value


Error Example HTTP/1.0 500 Server ErrorDate: Sun, 21 Nov 2004 14:55:57 GMTConnection: closeServer: Systinet WASP Server for Java/5.0 (Java/1.5.0; Windows XP/5.1)SOAPAction: ""Content-type: text/xml;charset=UTF-8X-WASP-Message-ID: 11e-FLxtbx/tDgWbei5OeHEwbw==<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <e:Envelope xmlns:d="http://www.w3.org/2001/XMLSchema" xmlns:e="http://schemas.xmlsoap.org/soap/envelope/" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:wn0="http://systinet.com/xsd/SchemaTypes/"

xmlns:wn1="http://idoox.com/interface"><e:Body><e:fault> <wn0:fault_code>e:Server</wn0:fault_code> <wn0:string_Fault i:type="d:string">Service is not Exist</wn0:string_Fault></e:fault> </e:Body></e:Envelope>


SOAP Message with Attachements

SOAP Message with Attachments


SOAP PackagesSource : www.soapuser.com

• Apache SOAP for Java(req lib are Xerces)• Apache Axis for Java• Systinet WASP for C++• Microsoft Toolkit (part of .net Frame

Work)• SOAP::Lite for Perl• Lucin SOAP toolset for Windows• IBM Alphaworks WSDL ToolKit• Simon Fell’s PocketSOAP


Apache SOAP

• Allow clients and server written in Java

• Part of Apache-XML project(http://xml.apache.org/#soap)

• SOAP Package downloadablehttp://xml.apache.org/dist/soap/

• Installation Instruction :http://www.xmethods.com/gettingstarted/

apache.html


Apache Soap Installation

c:

SOAP %tomcat home%

Soap 1.1

lib

Xerces.jar Mail.jar Soap.jaractivation.jar

Webapps

Jsp

web-inf

classes


Classpath Setting

• Set classpath= %classpath%;%HomeDir%\soap\soap1.1\xerces.jar;%HomeDir%\soap\soap1.1\soap.jar;

%catalina_home%\lib\servlet.jar;.;


Writing a client Application using Apache Soap

Classpath Your CLASSPATH environment variable should have both the "soap.jar" and "xerces.jar" JAR files included. Importing packages For basic SOAP method invocation, you should import the following at minimum:

// Required due to use of URL class , required by Call class import java.net.*;

// Required due to use of Vector class import java.util.*;

// Apache SOAP classes used by client import org.apache.soap.util.xml.*; import org.apache.soap.*; import org.apache.soap.rpc.*;


SOAP Datatypes• SOAP Datatypes

http://www.sdc.iup.edu/outreach/spring2002/webservices/datatypes.html

• Uses XML Schema datatypes• Primitive types

string, boolean, decimal, float, double, duration, dateTime, time, date, gYearMonth, gYear, gMonthDay, gDay, gMonth, hexBinary, base64Binary, anyURI, QName, NOTATION

• Derived typesSimple types (derived from a single primitive type)* integer is derived from decimal* int (-2147483648 <= int <= 2147483647) is derived from long which is derived from integer * 5-digit zip code can be derived from int* may use regular expressions to specify derived types, such as ([A-Z]){2,3}-\d{5}


Complex Types• Struct example

<instructor> <firstname xsi:type="xsd:string">Ed</firstname>

<lastname xsi:type="xsd:string">Donley</lastname> </instructor>

• Array example <mathcourses xsi:type="SOAP-ENC:Array" SOAP-

ENC:arrayType="se:string[3]"> <se:string>10452C</se:string> <se:string>10454C</se:string> <se:string>11123T</se:string> </mathcourses>


Implementation of Systinet


Summary

• SOAP is a protocol that makes use of HTTP requests and responses to effect remote method calls to webservices

• A SOAP method call is encoded in XML and is embedded in an HTTP request

• A number of SOAP APIs are available for programming web services but apache was first introduced.


References • Standard Documents

– http://www.w3.org/TR/soap/– http://www.w3.org/2002/ws/– http://www.w3.org/TR/2002/CR-soap12-part0-20021219/ (This material defines entire SOAP Primer)

• Articles – Data Types

http://www.sdc.iup.edu/outreach/spring2002/webservices/datatypes.html

– http://www.soapuser.com/resources.html– http://www.topxml.com/soap/– www.soaprpc.com

Web Services & SOAP Protocol Sravan Kumar Ananthula.

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