Department of Computer Science and Engineering Dr. Yinong Chen

Lab#7

SOA Programming

Overview

In this lab, you will create service-oriented software that consists of the services found in

the public service directories. The purpose of this lab is to exercise service development

and application composition. Some of the required operations are synthetic, while others are

realistic. The software will be implemented using Visual C# on Visual Studio .Net 2005.

2

What is SOA and SOC?

Service-Oriented Architecture (SOA) is a software system consisting of a collection of

loosely coupled services (components) that communicates with each other through standard

interfaces (Tsai). These services are platform independent (can be operated in different

operating systems), and can be run separately from other services. Technically speaking, a

service is defined as an interface between the developer (the producer) and its customers

(the consumers). The goal of a service is to create a well-defined and well-contained set of

functions that be used by the consumers to form a larger service (component). Thus

services are often described as agents that conduct their work and pass their results to

the next agent(s).

While we use the terminology Service-Oriented Architecture (SOA) to describe a software

system as Service-Oriented, Service-Oriented Computing (SOC) refers to the paradigm

that represents computation in SOA. A paradigm is set of basic principles, concepts, and

methods of how computation or algorithms are expressed. In traditional software

development paradigms, the developer will take the requirements and convert them into

specifications, and then translate them into an executable program. However, SOC takes a

different approach.

Evolved from object-oriented computing and component-based computing, SOC splits the

developers into three independent, but collaborative entities. The first entity is the

service developers (or service providers); their primary responsibility is to develop software

3

services (either local based or web services). The second entity is the service brokers (or

the publishers); their primary responsibility is to publish and/or market the available

services. The last entity is the application builders or the service requestors, their primary

responsibility is to find available services through the service brokers and use the services

to develop their new applications. Unlike the traditional paradigm, the application

development is now done via discovery and composition rather than traditional design and

coding.

Figure 1 shows an overview of a typical web-service architecture using SOC paradigm. From

the diagram, we can see the application development is a collaborative effort involving these

parties: service developers, service brokers, and application builders. Because services are

platform-independent and loosely coupled, many of the same types of services can be

developed by many different service developers or providers. Therefore, service brokers

will normally rank these services and display the best services at the top of their list. An

example includes “add-to-cart” services; because this type of service is very common in all

online retailer shops (e.g. Circuit City, Amazon, and Best Buy), many service providers could

implement and publish the same service for the application builder to use in their web

application. That is the reason why service brokers (e.g. WebStrar) will rank each type of

services to provide the application builders with the best service available.

Figure 1: A Typical Web-Service Architecture

4

In order to publish a web service onto the web, the service brokers must uses UDDI or

ebXML protocols that provide a set of standard interface to register and publish the web

service. Under the UDDI (Universal Description Discovery and Integration) protocol, the

information needed for registering a service includes: (1) White page information: Service

provider's name, and contact information. (2) Yellow page information (business category):

industry type, product and service type, and geographical location. (3) Green page

information: technical detail how other Web services can access (invocate) the services,

such as APIs (Application Programming Interfaces).

EXPERIMENT

Now that you have an idea about SOC and Web Services, you are ready to begin the

experiment.

In this experiment, you will be asked to create a window application to locate movie

theaters in your community. You be using third-party web services to create this

application. The experiment is split into three parts: (1) building a Windows application, (2)

discovering and invoking web services, and (3) coding.

5

Part 1: Creating a Windows Application?

Open Visual Studio .NET 2005 and create a new project. Select “Visual C#” as your

project type. Instead of selecting “Console Application,” please select “Windows

Application” for your template. Then name this project “L7_MovieApp_TeamName” and

click OK. (See figure 2: A New Windows Application)

Figure 2: A New Windows Application.

Notice the difference from your last lab? Instead of just seeing code in the code editor,

you also see design view. The design view allows you to customize the GUI (Graphical User

Interface) application using the toolbox located on the top-left of the screen (See figure

3).

6

Figure 3: Visual Studio Environment with Design View in the Code Editor.

STEP 1: Create a textbox and a corresponding label to prompt the user to enter their zip

code.

1. First click on Toolbox and a list of controls will appear.

2. Double-click on “All Windows Forms,” the menu should expand.

3. Select the “Label” control from the Toolbox and drag it into the form.

a. Inside the properties window, change the (Name) from “label1” to

“lblZipCode.”

b. Inside the properties window, change the Text from “label1” to

“Enter ZIP: “

4. Select the “Textbox” control from the Toolbox and drag it into the form next to

“lblZipCode”.

a. Inside the properties window, change the (Name) from “textBox1” to

“txtZipCode”.

Toolbox

Form

Properties Window

Solution Explorer

7

STEP 2: Create a button for the user to click after they have entered their zip code.

1. Select the “Button” control from the Toolbox and drag it into the form next to

“txtZipCode”

a. Inside the properties window, change the (Name) from “button1” to

“btnLocate”

b. Inside the properties window, change the Text from “button1” to “Locate”.

STEP 3: Create a radio button list.

1. Select the “GroupBox” control from the Toolbox and drag it into the form.

a. Inside the properties window, change the (Name) from “groupbox1” to

“grpRadiusLoc”

b. Inside the properties window, change the Text from “groupBox1” to “ Find

location within ”

2. Select the “RadioButton” control from the Toolbox and drag it into the form, inside

“grpRadiusLoc”

a. Inside the properties window, change the (Name) form “radioButton1” to

“btn15miles”

b. Inside the properties window, change the Text from “radioButton1” to “15

miles”

3. Repeat step 2 for 20 miles. Make sure to change the (Name) to “btn20miles”.

4. Select “btn15miles” and in the properties window, set checked to “True”.

STEP 4: Creating an output for the result.

1. Select the “RichTextBox” control from the Toolbox and drag it into the form.

a. Inside the properties window, change the (Name) from “richTextBox1” to

“txtResult.”

2. Your application should look something like figure 4.

8

Figure 4: Window Application after Step 4.

When you are done with this part, please notify the lab instructor for check–off.

Part 2: Discovering and Invoking Web Services

The next part of this experiment is to map a web service onto your Windows Application.

You will be using a third-party service, from http://www.xmethods.com. To add a Web

reference to your project, follow these steps:

STEP 1: Locating the Web Service

1. To begin, open your web browser and enter the following URL

(http://www.xmethods.com) into the address bar and press “enter.”

2. Once the page has been fully loaded, search through the website for a service called

“Ignyte's Retrieve Theaters and Movie Showtimes.” You may have to expand the

entire list to find this service. Click on the link and this should take you to the next

page (see Figure 5).

9

Figure 5: Ignyte’s Web Service

3. Copy the WSDL address from this page. You will need this address to invoke the

web service.

STEP 2: Adding web services to your application.

1. Return to Visual Studio .NET environment. Choose project Add Web References.

You can also right-click the name of your project in the Solution Explorer and select

the Add Web Reference option from the shortcut menu.

2. Paste the WSDL link into the URL and press enter. See figure 6.

3. Once the service has been found, rename the web reference name to

“proxyTheaterLocator” and click “Add Reference”

4. Verify that the reference has been added successfully by opening the Solution

Explorer (press Ctrl+Alt+L) and viewing the project node. You should see a Web

References directory with a reference called “proxyTheaterLocator.” See figure 7.

10

Figure 6: Adding a New Web Reference.

Figure 7: Solution Explorer.

When you are done with this part, please notify the lab instructor for check–off.

11

Part 3: Coding

In this section, you will begin coding our application. Please verify that all control (Names)

are labeled correctly (see figure 8). Remember C# is case-sensitive.

Figure 8: Controls with its Corresponding Labels.

STEP 1: Adding code to “btnLocate”

1. In the Design View, double-click the “Locate” button. The code editor appears and

displays a method named btnLocate_Click. This method, an event handler, handles

the click event for this button.

2. Type in the following code to this method:

txtResult

btnLocate

btn15miles btn20miles

txtZip

12

private void btnLocate_Click(object sender, EventArgs e) { int indexA, indexB; int radius; if (btn15miles.Checked) // Check if btn15miles was selected { radius = 15; } else if (btn20miles.Checked) { radius = 20; } else { radius = 15; } // Proxy to activate and use the web service // The proxy requires a ZIP Code (type string) and a radius (type integer) proxyMovieLocator.MovieInformation theater = new L7_MovieApp_TA.proxyMovieLocator.MovieInformation(); proxyMovieLocator.Theater[] theaterDS = theater.GetTheatersAndMovies(txtZipCode.Text.Trim(), radius); // Printing the result out using array txtResult.Text = ""; for(indexA = 0; indexA < theaterDS.Length; indexA++) { txtResult.AppendText(theaterDS[indexA].Name.ToString() + "\n"); txtResult.AppendText(theaterDS[indexA].Address.ToString() + "\n"); for (indexB = 0; indexB < theaterDS[indexA].Movies.Length-1; indexB++) { txtResult.AppendText(theaterDS[indexA].Movies[indexB].Name.ToString() + "\n"); try { txtResult.AppendText(theaterDS[indexA].Movies[indexB].Rating.ToString() + "\n"); } catch (NullReferenceException) {}

13

try { txtResult.AppendText(theaterDS[indexA].Movies[indexB].RunningTime.ToString() + "\n"); } catch (NullReferenceException) {} try { txtResult.AppendText(theaterDS[indexA].Movies[indexB].ShowTimes.ToString() + "\n"); } catch (NullReferenceException) { } } txtResult.AppendText("\n\n"); } }

Figure 9: Code to Utilize the Web Service.

When you are done with this part, please notify the lab instructor for check–off.

What is this method trying to do? For each statement in the program, insert a comment stating what this line does. Example: int counter; \\ Initialize an integer variable call counter.

14

STEP 2: Customizing the program.

1. To expand the search area, please add two (2) more distances (25 and 30 miles) to

“grpRadiusLoc.”

a. You will need to update the code to reflect these changes as well.

b. When you are done with this part, please notify the lab instructor for check–off.

2. Next, you need to change the output format to match the figure below (figure 10):

Harkins Shea 14 7354 E. Shea Blvd., Scottsdale, AZ Employee of the Month (PG-13) 1 hr 43 mins 12:10pm | 2:40pm | 5:10pm | 7:40pm | 10:05pm

Figure 10: Sample Output

a. Hint: You will need to change the code to display the result differently.

b. To change the font and the font style use the following segment of code:

txtResult.SelectionFont = new Font("Tahoma", 10, FontStyle.Underline);

c. When you are done with this part, please notify the lab instructor for check–off.

3. Lastly, you will need to include a search field in your application. This field is used to find

theaters that are showing only that particular movie.

a. You will need to include an additional textbox for users to enter a movie that they

like to see.

b. The textbox is not case-sensitive and will accept both upper and lower-case input.

(HINT: When you are do comparisons, switch your data to all uppercase or

lowercase before comparing the data.)

c. The textbox is an optional field; therefore, if a user left the textbox blank, you

will need to display all the theaters within that location.

d. When you are done with this part, please notify the lab instructor for check–off.

15

EEE/CSE 101 – Introduction to Engineering Design Check-In/Check-Out/Verification Sheet Lab 7: SOA Programming Group Number & Name: Station ID: Session Date: Students’ Names and Check-in/Check-out Time: Member Name Check-In Time Check-Out Time TA Signature 1. _____________________ _____________ ______________ ____________ 2. _____________________ _____________ ______________ ____________ 3. _____________________ _____________ ______________ ____________ Equipment Verification: TA Signature CHECK IN: Speedy-33 Webcam Headphones ___________________ CHECK OUT: Speedy-33 Webcam Headphones ___________________

Items to be checked Part 1: GUI Complete TA Signature:

Part 2: Discovering the Web Service TA Signature:

Part 3: Coding the Application TA Signature:

Expanding the search area TA Signature:

Customizing the output TA Signature:

Creating a search field TA Signature:

All above items and lab report submitted to Digital Drop Box as a single archived file TA Signature:

Comments (TA use)