95-702 Organization Communication and Distributed Object Technologies

Homework 3 Using Axis2 for web services

Part I. Prerequisite Installations 
----------------------------------

    1) Tomcat is installed and is available through Eclipse.
    2) The Axis2 Standard Binary Distribution has been installed from the   
       following site: http://ws.apache.org/axis2/download/1_2/download.cgi.
    3) The file named "axis2.war" has been placed in Tomcat's directory structure at
       .../apache-tomcat-6.0.10/webapps/axis2.war.
    4) Axis2.war has been expanded into a directory called axis2 at
       .../apache-tomcat-6.0.10/webapps/axis2.
    5) The expansion of axis2.war into the directory axis2 is performed
       by Tomcat.
    6) The axis2 directory contains META-INF, WEB-INF and axis2-web 
       subdirectories.
    7) A visit to http://localhost:8080/axis2
       shows services, a validation tool and an administration tool.
    8) Two axis2 plugins for Eclipse have been installed.
       These are:
          The code generator wizard at 
          http://ws.apache.org/axis2/0_94/CodegenTools-EclipsePlugin.html
          The archiver wizard at
          http://ws.apache.org/axis2/tools/1_1/eclipse/servicearchiver-plugin.html
    9) These wizards are available from within Eclipe with
       file/new/other/axis2 wizards.

Part 2 Writing a simple web service
===================================

Start Eclipse.

Choose any workspace name.

Create a Java Project with separate source and output folders:

   file/new/project/java project/next/
   Project name: HelloWorldWS
   Create separate source and output folders
   Finish


Create a package called ws.first:

   file/new/package
   name: ws.first
   finish

This ws.first should be shown under src.

Create Java class called HelloWorldWebService.java.

This class will be in the ws.first package:

   select ws.first
   file/new/class
   name: HelloWorldWebService
   finish

Enter the following code in the file HelloWorldWebService.java:

package ws.first;

public class HelloWorldWebService {

	public String hello(String name) {
		return "Hi " + name;
	}
	public String goodBye(String name) {
		return "goodbye " + name;
	}
	
}


Create the services.xml file
----------------------------
   Select the project.
   File/new/file
   Name: services.xml

   Use the following code:

<service>
  <description>My Cool Hello world web service</description>
  <parameter name="ServiceClass">ws.first.HelloWorldWebService</parameter>
  <operation name="hello">
    <messageReceiver class="org.apache.axis2.rpc.receivers.RPCMessageReceiver"/>
  </operation>
 <operation name="goodBye">
    <messageReceiver class="org.apache.axis2.rpc.receivers.RPCMessageReceiver"/>
 </operation>
</service>



Placing axis2 jar files in your classpath
=========================================

There are two possibilities here. If this is the first
time you have done this you need to associate a variable
name with all of the axis2 jar files. These instructions
follow:

   If this is the first time do {

     Select project HelloWorldWS.
     Right click/ Properties/ Java Build Path.
     Libraries/add library/user library/next/user libraries/new.
     Enter the user libray name axis2_lib.
     Select axis2_lib and select addJars.

     This is a very tedious process but needs to be done only once.
     Browse to axis2-1.1.1/lib and select one jar at a time.
     When two jars have a different version number select only the one with         
     the latest version.
     The pattern is select axis_lib, click add jar, double click an axis2    
     jar file, repeat.
     All the jars should be under the name axis_lib.
     When complete, choose to export this jar list to the file system. 
     You'll need a file name.

     When you finish the Java Build Path will contain the JRE System 
     Library and the axis2_lib.

     Both of these jar lists should appear under your project.
   }
   else (you already have performed this activity) do {

      Right click project / properties
      Select Libraries/ add library
      Select user library
      next/ User Libraries/ import / browse to the old library
      Your project should have two large lists of jars
      One from the JRE and the other from Axis2.
   }


Build the archive file to be placed under Tomcat
------------------------------------------------

Select the project.
File/New/Other/Axis2 Wizards/Service Archiver/next

Class File Location
Browse to this project's bin directory
Check include class files only
select next

Select Skip WSDL select next

Add libraries? No, just select next.

Browse to the services.xml file.
Select next.

The output file location is under Tomcat.
Browse to ...tomcat/webapps/axis2/WEB-INF/services
The output file name is HelloWorld

Select Finish and the service archive is now behind Tomcat.

Tomcat Preparation
==================

   Window/preferences/tomcat
   Version 5.x
   Browse to Tomcat Home (mine is /usr/local/apache-tomcat-6.0.10)

   Advanced Tomcat Base browse to Tomcat Home
   Do Not Check add java projects to Tomcat Classpath

   JVM Settings: Set JRE
   Source Path: Do Not check add java .... HelloWorldWS

   Manager: User name and password

Run Tomcat
==========

   Click the cat.
   No exceptions are thrown.

   Visit http://localhost:8080/axis2
   Look for services: HelloWorld
   View the wsdl at http://localhost:8080/axis2/services/HelloWorld?wsdl

Client Side Coding
==================

   We'll work within the same project to create a client.
   First we need to create a stub class. And for fun,
   we'll generate a wsdl.


File/New/Other Axis2 Code Generation wizard

   Generate WSDL from Java source next.
   Postpone entering the file name.
   Select add folder. Browse to this project's bin folder (not Tomcat bin).
   Enter the qualified class name ws.first.HelloWorldWebService. 
   Click Test Class Loading (this may erase an error message.)
   Select Next.
   Take the defaults select Next again.
   Browse and add wsdl to project on current eclipse workspace.
   Be sure to actually browse to the workspace
   and select the project name folder.

   Hit Finish.

   File refresh.

   You should see the wsdl under the project.

   Generate a stub from the wsdl to be used by a client.
  
   Select the project.

   File/New/Other/Axis2 Codegen

   Generate Java source code from a WSDL

   Browse to the wsdl under the project folder

   Use the defaults select next

   Select Browse and select a project on current eclipse workspace

   Select finish

   Create the client HelloWorldWebServiceClient in the package ws.first

package ws.first;

import java.rmi.RemoteException;

import org.apache.axis2.AxisFault;

public class HelloWorldWebServiceClient {


  public static void main(String[] args) {
	  HelloWorldWebServiceStub stub;
    try {
      String  c_value = "Mike";
      
      stub = new HelloWorldWebServiceStub
	 		("http://localhost:8080/axis2/services/HelloWorld");
      
      System.out.println("Stub created");
     
      HelloWorldWebServiceStub.Hello x
      	= new HelloWorldWebServiceStub.Hello();
      
      x.setName(c_value);
     
      System.out.println("set name called with " + c_value);
      
      HelloWorldWebServiceStub.HelloResponse res 
        = stub.hello(x);
      
       System.out.println("Returned");
       System.out.println("C Value : "+c_value+ "\tResult : " +res.get_return());
      
        } catch (AxisFault e) {
        	e.printStackTrace();
        } catch (RemoteException e) {
                e.printStackTrace();
        }
  }
}


Run the client. If all goes well you should see
Stub created
set name called with Mike
Returned
C Value : Mike	Result : Hi Mike