session 2 evolution web service and primitive soa

7/27/2019 Session 2 Evolution Web Service and Primitive SOA

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SOA Concepts

605.702 Service Oriented ArchitectureJohns-Hopkins University

Montgomery County Center, Spring 2009Session 2: Lecture 2, February 4, 2009

Instructor: T. Pole


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Session #2 Todays Agenda Required Reading (to be read before class)

Erl Chapter 4: The Evolution of SOA Erl Chapter 5: Web Services and Primitive SOA

Todays Presentation

Todays Lecture Review Chapters 1, 2 (and finish 3)

Introducing SOA (Ch 3)

Evolution of SOA (Ch 4)

Web Services and Primitive SOA (Ch 5) Content Management and the CMIS (additional material)

Setting up the environment Visual Studio 2008

Windows XP preferred (Vista also works. May need specific version, with configuration)

Client Implementation with SOAP and .Net Building the Client

Referencing the Server

Running the client

Assignments Exercise 1 (due 2/11/2009) Building a Web Service Client


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Review Last Week

Not a lecture, but an opportunity for you to

ask questions

Chapter 1: About the Book

Chapter 2: About the Case Studies

General Discussion

What is a Service?

What is a Web Service?

What is Service Oriented Architecture?


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Ch 3 Introducing SOA Section 3.1 Fundamental SOA

Services encapsulate logic within a distinct context

Context == business task or business entity or any logical

grouping

Varied scales == a process step, set of steps or the entire

process Services are related via relationships

Services communicate via messages which are

independent units of communication

Service design promotes: loose coupling, contract drivencomposability, autonomy, discoverable stateless reusable

components

To this point we have described primitive SOA


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Section 3.2: Defining SOA

Section 3.2 Common Characteristics of

Contemporary SOA

See list of primary characteristics, page 40-41

3.2.20 Defining SOA page 54


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Section 3.3 SOA Misperceptions

3.3.1 thru 3.3.3: Major Misperception #1: SOA is NOT reallysomething new NOT Some validity, but the combination of Old ideas, as well as

some new ideas synthesizes a new approach: th whole is greaterthen the sum of its parts.

3.3.4: SOA Simplifies: NOT The point is not to simplify the solution to the problem, but to

simplify performing individual steps in solving he problems, and inthe integration of those resultant steps into the complete solution.

3.3.5 thru 3.3.6: SOA is Web Services, or WS with someextensionsNOT

Those are just technologies used to implement SOA 3.3.7 SOA makes everything interoperable NOT

If you design and build an SOA system properly, its pieces areinteroperable with similar good SOA systems


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Section 3.4 SOA Benefits and the start of

a Business Case for SOA

3.4.1 thru 3.4.3: Component Based Software

Engineering benefits:

Integration of components, reuse of components,

streamlined architecting of components into solutions.

Business Case is reduction of effort, solving multiple

problems with single work products.

3.4.4 Leveraging the Legacy Systems

Retaining and (optionally) controlling the evolutionary

replacement of legacy systems

Business Case is extending usable life of past investments


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Section 3.5 Common Pitfalls in Adopting

SOA

Designing an SOA as though it were a traditional

distributed architecture

Question: What kinds of systems should not be designed

as SOA?

Not having an XML foundation

What problem is it that XML solves?

Not understanding SOA Performance and Security

What does SOA change in designing for Performancerequirements?

What does SOA change in designing for Security

requirements?


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Chapter 4: The Evolution of SOA Section 4.1 An SOA Timeline

XML Initially a publishing tool

Then a data format tool

Now a service oriented version of a remote procedure callprotocol

Web Services Initially port 80 tunnelling

Initially Simple Object Access Protocol

Now (with WS-*) much more complex

Security

Dependable delivery Orchestration

SOA

Forced evolution of XML and Web Services


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Section 4.2: Continuing Evolution of SOA

Standards, Specifications, and Extensions

Standards Organizations

Vendors

Distributed Tool and System Vendors

Forward Thinking, Imaginative Vendors

Not a good thing, notice the quotation marks above


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Section 4.3: Roots of SOA

A distributed integration/communication

protocol

Can be synchronous or asynchronous

HTTP basis of most SOAP implementations

forces some call and response behavior

Can be used to wrap non Service Oriented

components, integrating their functionality into an SOA


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Chapter 5Web Services and Primitive SOA

Section 5.1 Web Services Framework

Services exposed through a Web Server, usually

via SOAP (sometimes other protocols such as

REST) that may or may not be service oriented

Primitive SOA (simplistic definition) SOAP

WSDL

UDDI


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Section 5.2 Service Descriptions: Roles

and Models

Business Service Model

Encapsulate operations related to this business

processes

Utility Service Model Encapsulates operations related to infrastructure,

basic system engineering functions

Controller Service Model Controls multiple services for a high level, more

complex, larger scope task


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Section 5.3 Service Descriptions

WSDL

Describes a service

What operations does it publish

Programmatic interface specification level ofdescription

Supports export of common data types as well


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Section 5.4 Messaging with SOAP

Types of Service Nodes Soap Sender

Initiates a communication between two nodes (services)

Initial Senderin a serial chain of SOAP message exchanges,

the first node in the change

Soap Receiver Received the SOAP envelope

Ultimate Receiverin a serial chain of SOAP message

exchanges, the node that only responds, it does not send another

message on to another node

SOAP Intermediary Receives a SOAP message and passes on a SOAP message

Active IntermediaryCan change the SOAP message before

passing it on


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Implementing Web Services

We will have an in class tutorial tonight on developing

web services on XP Pro, IIS, and Visual Studio.

You can build and test Web Services without IIS. But

for other computers to reach those web services, aSOAP enabled Web Server, sometimes (erroneously)

called a SOAP Application Server, IIS must be used to

deploy them.

This will help you get started by getting, VS 2008 and

the .Net framework up and running and being able to

build a client for a basic Web Service using C#.


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How to: Setup Visual Studio 2008 Pro Register with Microsoft DreamSpark

www.dreamspark.com https://www.dreamspark.com/FAQ/Students.aspx#universit

yStudentVerification

Download Visual Studio 2008 Download:https://www.dreamspark.com/Products/product.a

spx?productid=1 Get Key: at bottom of page

System_Requirements:http://www.microsoft.com/visualstudio/en-us/products/professional/default.mspx

Fairly simple installation procedure

Select max install you have disk space for Select .Net 3.5, install MSDN documentation

SQL Server and ther tools are optional

Any additional questions, email me.
http://www.dreamspark.com/https://www.dreamspark.com/FAQ/Students.aspxhttps://www.dreamspark.com/FAQ/Students.aspxhttps://www.dreamspark.com/Products/product.aspx?productid=1https://www.dreamspark.com/Products/product.aspx?productid=1http://www.microsoft.com/visualstudio/en-us/products/professional/default.mspxhttp://www.microsoft.com/visualstudio/en-us/products/professional/default.mspxhttp://www.microsoft.com/visualstudio/en-us/products/professional/default.mspxhttp://www.microsoft.com/visualstudio/en-us/products/professional/default.mspxhttp://www.microsoft.com/visualstudio/en-us/products/professional/default.mspxhttp://www.microsoft.com/visualstudio/en-us/products/professional/default.mspxhttps://www.dreamspark.com/Products/product.aspx?productid=1https://www.dreamspark.com/Products/product.aspx?productid=1https://www.dreamspark.com/FAQ/Students.aspxhttps://www.dreamspark.com/FAQ/Students.aspxhttp://www.dreamspark.com/


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How to Build a Windows Console

Application 1 of 3

Start Visual Studio (VS 2008)

File -> New -> Project

Choose the Console Application template

Type in a path to where you will store the files forthis application

Be sure the Project Type tab is C#

Enter a name in the project Name textbox, and

optionally the same or different name in the SolutionName

Click OK


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How to Build a Windows Console

Application 2 of 3

The Solution Explorer Window shows Files, settings, etc.

There is a file named Program.cs. Which is the

source file for this project Select with right mouse button in explorer

windows, left of screen add service reference

Click Advanced button At bottom of Service References Settings click

Add Web Reference


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Build a Web Service Client 3 of 3

In URL enter http:areopagus-

soa.net/TP_Sample01_SimpleWebServer/Se

rvice.asmx

Enter meaningful name in Web Reference

Name textbox, e.g. SimpleWebService This is the namespace for the reference to the

web service

Click Add Reference button


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Code Sample for Client

string FirstName, LastName;

Console.Out.WriteLine( "Enter first name:" );

FirstName = Console.In.ReadLine();

Console.Out.WriteLine( "Enter last name:" );

LastName = Console.In.ReadLine();

Console.Out.WriteLine("Creating proxy for web service.");

SimpleWebService.Service Server = newtestapp_020209.SimpleWebServer.Service();

Console.Out.WriteLine("Invoking opertion");

string Result = Server.SaveMyName(FirstName, LastName);

Console.Out.WriteLine("Result is " + Result);Console.Out.WriteLine("Enter to exit");

Console.In.ReadLine();


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Build and Debug/Run the Client

Menu: Build -> Rebuild Solution

Menu: Debug -> Start Debugging


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How To: Setting Up Windows XP IIS

Server

IIS is an optional install on Windows XP Pro

Control Panel->Add/Remove programs

->Add/Remove Windows Components->

Select Internet Information Services (IIS)->Next, Finish

Select the Front Page 2000 Extensions option

http://localhost


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FAQ (.Net Web Service Development)

I've installed the .NET Framework, but ASP.NETdoesn't seem to work. What can I do to fix it? You must have IIS (Internet Information Services) installed

before you install the .NET Framework.

If you install IIS after you install the .NET Framework, you

must also register the ASP.NET extensions with IIS. You can do this by running the aspnet_regiis executable from:

%windows root directory%\Microsoft.NET\Framework\%versionof the .NET Framework%\aspnet_regiis -r

where %windows root directory% is the directory Windows isinstalled to (typically c:\windows or c:\winnt)

and %version of the .NET Framework% is the version of the.NET Framework you have installed.

The directory for .NET 1.0 is v1.0.3705, for 1.1 is v1.1.4322, andfor 2.0 is v2.0.50727


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Exercise 1: Build a Client for the Simple

Web Service

The Web Service is at:Areopagus-soa.net/TP_Sample01_SImpleWebServer/Service.asmx

Build a simple client that can invoke the operation:

SaveMyName

Use the WSDL to read the interfaceAreopagus-soa.net/TP_Sample01_SImpleWebServer/Service.asmx?wsdl

Also available from the generated C# code after you add a

reference to the Web Service

Due next week

Email me the executable and the source file Program.cs

In the bin/debug folder

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