1. Labs: Create, deploy and test a simple web service
SOA concept
Web service: components and implementation approaches
Activity 1: Implementing a simple web service

2. What is SOA
A set of principals and practices for modeling enterprise business functions as web services or micro services which have following attributes:
Standardized
Loosely coupled
Reusable
Composable
Autonomic
...

3. Outline of SOA
The standard SOA model (Figure 1) introduces three key actors:
a web service 'provider' which makes services available and is also responsible for publishing a description of the service in one or more service directories.
a web service 'broker', who maintains a searchable directory of service descriptions.
a service 'requestor' or 'client' who wishes to find and use a service.

4. Components of web service
From an implementation point of view, a web service has:
Service logic, i.e. the work required to provide the service function
An interface (implemented in XML) describes how to put a request to the service and what to expect as response

5. Implementation approaches
Bottom-up approach – the code is written first, then the WSDL is produced and published in UDDI (the service code is placed inside a container that provides the required interface for messaging – usually SOAP)
Top-down approach – firstly, produce the WSDL, i.e. XML description of the service (what it does, how it can be called, what results it returns), and then this specification is used as a guide to writing the code that implements the service.

6. Activity 1: Implementing a simple web service
Lab 1: Setting up your Environment (already set in clasroom)
Step 1: Application Server installation - Install Apache Tomcat Server
Step 2: Eclipse IDE for Java EE Developers installation
Step 3: Add a ServerRuntimeEnvironment
Lab 2: Create a Dynamic Web Application project
Step 1: Writing the service logic
Step 2: Generating a web service and client
Step 3: Testing the web service
Step 4: Monitoring web service messages

7. Lab 1: Setting up your Environment
Step 1: Application Server installation
(There are a wide range of application servers such as IBM WebShere, JBoss, BEA’s WebLogic server etc. However, we will focus on use of Apache Tomcat since it is a popular, commercially used but open source (free) application server)
Install Apache Tomcat Server:
Go to:
Click on the latest version, e.g.:
Find your Windows version, e.g. under Core choose:
64-bit Windows zip
Under folder “c:\Program Files\” unzip the Application Server software :
C:\Program Files\apache-tomcat M17-windows-x64.zip
Note that you should have jdk already installed. Check the path:
C:\Program Files\Java\jdk1.8.0_91

8. Lab 1: Setting up your Environment
Step 2: Eclipse IDE for Java EE Developers installation
Go to
Click on:
Run Eclipse eclipse-inst-win64.exe

9. Lab 1: Setting up your Environment
Step 3: Add a ServerRuntimeEnvironment
Launch Eclipse and invoke the command from the menu bar:
Window > Preferences
Expand the Server category
Click on Runtime Environments
Click Add button to open the New Server Runtime Environment window
Expand the Apache category, and select Apache Tomcat v9.0, click on Next
Click the Browse button to select the directory where Tomcat is installed
The JRE field is initialized to the Workbench default JRE, which is the JVM you used to laund Eclipse – click on Finish
Tomcat is now listed (Figure on the next slide)
With extended Eclipse with a J2EE servlet container you are ready now to create your first Java Web application development project.

10. Added a server runtime environment

11. Lab 2: Create a Dynamic Web Application project
Launch Eclipse
If the Project Explorer is not open in Java EE perspecitve, then use Window > Open Perspective, and select Java EE
The first step is to create a project that will be used to hold all the code and other elements that will make up your web service:
Select File > New > Project, open up the Web folder and select Dynamic Web Project
Type a Project name: Hello, and click Finish.
Expand the project titled Hello to view the components

12. Step 1: Writing the service logic
In the Eclipse Project Explorer, expand the Hello project
Right-click on the Java Resources: src, and select New > Class
Enter Package name: Hello
Enter the class name: Hello, and click Finish.
Enter the class code:
Save the code using File > Save.
If all is well done you should find that Eclipse has compiled the source code “Hello.java” (under projects build directory)

13. Step 2: Generating a web service and client
Until now you have created an empty Dynamic Web Service project and added the code you need to turn into a web service.
Throught the next wizard, Eclipse will do the rest of the work for you by:
Packaging the web service up with an XML interface
Deploying the web service to an application server of your choise
Starting the application server if required
Generating a set of web pages that can be used as a simple client to test the web service

14. Step 2: Generating a web service and client
Select the Hello.java in the Project Explorer
File > New > Other > Web Services > Web Service

15. Step 2: Generating a web service and client
Indicates that you are producing a web service from the bottom up based on some Java code. The slider controls what action Eclipse will take in terms of assembling, deploying, starting, etc. the web service. The Java proxy is a Java class that is generated as an application to implement the funcionality of the test client. It will be automatically generated and started as a web applicatoin running on Tomcat. The client should be generated in order to test the web service. Select to monitor the web service Click on Finish, that Eclipse can start to create and deploy the web service and make the client for testing the service.

16. Step 3: Testing the web service
When Eclipse has finished producing the web service and client, the next window will be displayed:
The Methods pane containes a list of the actions that the web service can be asked to perform.
The last method is defined by the Java code of the web service that you have created, so if you click on it the Inputs pane will display a text box labelled “name”.
The web service will send a response, which is displayed in the Result pane.

17. Service descriptions: Web service endpoint
Click on the method: getEndpoint(), and then click on Invoke (under Inputs pane).
Result pane will display the URL where the service resides and can be accessed.
The HTTP URL used to display the test client.
The URL is that of a Java Server Page (JSP) called “TestClient.jsp”, which includes the frames you are seeing (Methods, Inputs, and Result).
Copy the link and paste it to your favourite web browser.
JSP web page is simply a web page with ebedded Java code to provide additional functionality over HTML.

18. Step 4: Monitoring web service messages
Under TCP/IP Monitor, Eclipse displays request and response messages – that is a SOAP envelope with a simple body element.
The SOAP request:
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope
xmlns:soapenv=" xmlns:xsd="
xmlns:xsi="
<soapenv:Body>
<helloName xmlns="
<name>Nikola</name>
</helloName>
</soapenv:Body>
</soapenv:Envelope>
SOAP (Simple Object Access Protocol) is a protocol specification for exchanging structured information in the implementation of web services.
SOAP allows clients to invoke web services and receive responses independent of language and platforms.

19. The SOAP response:
<?xml version="1.0" encoding="utf-8"?> <soapenv:Envelope xmlns:soapenv=" xmlns:xsd=" xmlns:xsi=" <soapenv:Body> <helloNameResponse xmlns=" <helloNameReturn>Hello there Nikola </helloNameReturn> </helloNameResponse> </soapenv:Body> </soapenv:Envelope>

20. What is Axis?
Copy the actual web service URL into a web browser:

21. Axis and WSDL Axis is a commonly available library of code
Axis provide access to the WSDL document that it has generated for each service
The list of services is given at
Click on the wsdl link next to the Hello service, and you will see the complete WSDL document for this service, which Axis has generated.

22. Axis and WSDL
Eclipse and Axis provide a very good level of support for the development and description of web services.

23. What you have learnt?
to create the logic of the service and deploy this to the application server
to create a simple client and used this to test the service
to examine the SOAP message exchange
to generate the WSDL that could be used by other clients to use the service.
Video: