Web services are application components which communicate using open
protocols. Using Web Services we can publish our application's functions
to everyone. This tutorial provides step by step instructions to
develop Web Services using Axis2 Web Services / SOAP / WSDL engine and
Eclipse IDE. Let's start.
1. Setup the Development Environment
1.1. First you need to set up the development environment. Following
things are needed if you want to create Web Services using Axis2 and
Eclipse IDE.
Some Eclipse versions have compatibility issues
with Axis2. This tutorial is tested with Apache Axis2 1.5.2, Eclipse
Helios and Apache Tomcat 6.
1) Apache Axis2 Binary Distribution -
Download
2) Apache Axis2 WAR Distribution -
Download
3) Apache Tomcat -
Download
4) Eclipse IDE –
Download
5) Java installed in your Computer –
Download
1.2. Then you have to set the environment variables for Java and Tomcat. There following variables should be added.
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JAVA_HOME :- Set the value to jdk directory (e.g. C:\Program Files\Java\jdk1.6.0_21)
TOMCAT_HOME :- Set the value to top level directory of your Tomcat install (e.g. D:\programs\apache-tomcat-6.0.29)
PATH :- Set the value to bin directory of your jdk (e.g. C:\Program Files\Java\jdk1.6.0_21\bin)
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1.3.
Now you have to add runtime environment to eclipse. There go to Windows
–-> Preferences and Select the Server --> Runtime Environments.
There select Apache Tomcat v6.0 and in the next window browse your Apache installation directory and click finish.
1.4. Then click on the Web Service –-> Axis2 Preferences and browse
the top level directory of Apache Axis2 Binary Distribution.
2. Creating the Web Service Using Bottom-Up Approach
2.1 First create a new Dynamic Web Project (File --> New –-> Other…) and choose Web --> Dynamic Web Project.
2.2 Set Apache Tomcat as the Target Runtime and click Modify to install Axis2 Web Services project facet.
2.3 Select Axis2 Web Services
2.4 Click OK and then Next. There you can choose folders and click Finish when you are done.
3. Create Web Service Class
Now you can create a Java class that you would want to expose as a Web
Service. I’m going to create new class called FirstWebService and create
public method called addTwoNumbers which takes two integers as input
and return the addition of them.
3.1 Right Click on MyFirstWebService in Project Explorer and select New
–-> Class and give suitable package name and class name. I have given
com.sencide as package name and FirstWebService as class name.
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package com.sencide;
public class FirstWebService {
public int addTwoNumbers(int firstNumber, int secondNumber){
return firstNumber + secondNumber;
}
}
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3.2 Then, select File --> New –-> Other and choose Web Service.
3.3 Select the FirstWebService class as service implementation and to
make sure that the Configuration is setup correctly click on Server
runtime.
3.4 There set the Web Service runtime as Axis2 (Default one is Axis) and click Ok.
3.5 Click Next and make sure Generate a default service.xml file is selected.
3.6 Click Next and Start the Server and after server is started you can
Finish if you do not want to publish the Web service to a test UDDI
repository.
You can go to
http://localhost:8888/MyFirstWebService/services/listServices to see
your running service which is deployed by Axis2. You can see the WSDL by
clicking the link FirstWebService.
We have to use Eclipse every time when we want to run the service if we
do not create .aar (Axis Archive) file and deploy it to the server. So
let’s see how we can create it.
4. Create .aar (Axis Archive) file and Deploying Service
4.1 In your eclipse workspace and go to MyFirstWebService folder and
there you can find our web service inside services folder. Go to that
directory using command prompt and give following command. It will
create the FirstWebService.aar file there.
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jar cvf FirstWebService.aar com META-INF
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4.2 Then copy the axis2.war file you can find inside the Apache Axis2
WAR Distribution (You downloaded this at the first step) to the webapps
directory of Apache Tomcat. Now stop the Apache Tomcat server which is
running on Eclipse IDE.
4.3 Using command prompt start the Apache Tomcat (Go to bin directory
and run the file startup.bat). Now there will be new directory called
axis2 inside the webapps directory. Now if you go to the
http://localhost:8080/axis2/ you can see the home page of Axis2 Web
Application.
4.4 Then click the link Administration and login using username : admin
and password : axis2. There you can see upload service link on top left
and there you can upload the created FirstWebService.aar file. This is
equal to manually copping the FirstWebService.aar to
webapps\axis2\WEB-INF\services directory.
4.5 Now when you list the services by going to
http://localhost:8080/axis2/services/listServices you should be able to
see our newly added service.
5. Creating a Web service client
5.1 Select File --> New --> Other… and choose Web Service Client
5.2 Set he newly created Axis2 Web service
(http://localhost:8080/axis2/services/FirstWebService?wsdl) as the
Service definition. Then configure the Server runtime as previously and
click finish.
5.3 This will generate two new classes called FirstWebServiceStub.java
and FirstWebServiceCallbackHandler.java. Now we can create test class
for client and use our web service. Create new class called
TestClient.java and paste following code.
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package com.sencide;
import java.rmi.RemoteException;
import com.sencide.FirstWebServiceStub.AddTwoNumbers;
import com.sencide.FirstWebServiceStub.AddTwoNumbersResponse;
public class TestClient {
public static void main(String[] args) throws RemoteException {
FirstWebServiceStub stub = new FirstWebServiceStub();
AddTwoNumbers atn = new AddTwoNumbers();
atn.setFirstNumber(5);
atn.setSecondNumber(7);
AddTwoNumbersResponse res = stub.addTwoNumbers(atn);
System.out.println(res.get_return());
}
}
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Now you can run the above code as java application and you will get the output as 12 since we are adding 7 and 5.
Download the Eclipse project of the above example (Password:sara)
Your comments are welcome !
