March 2006

Building web services with Apache Axis

I. Assumptions:
==========
       (1) Your path variable contains C:\batch.

       (2) C:\batch has the following batch files:

       adminclient.bat
                java org.apache.axis.client.AdminClient  %1

       wsdl2java.bat
                java org.apache.axis.wsdl.WSDL2Java  %1

       tcpmon.bat
                java org.apache.axis.utils.tcpmon  %1

      (3) Your classpath includes all of the jar files required by Axis. For
            example, the classes AdminClient and WSDL2Java must be
            in a jar file pointed to by your classpath.

      (4) You have located your Microsoft wsdl.exe file. Mine was found in:
            C:\Program Files\Microsoft.NET\SDK\v1.1\Bin\wsdl.exe

      (5) You have located your Microsoft command line C# compiler. 
            Mine was found in:
            C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\csc.exe

      (6) Add the above paths to your path variable. Mine now reads:
            C:\Program Files\Java\jdk1.5.0_05\bin;
            C:\Program Files\Microsoft.NET\SDK\V1.1\Bin;
            C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322;
            C:\WINDOWS\system32;
            C:\batch;
            C:\Tomcat 5.5\bin;
            %ANT_HOME%\bin;
           
II. Building a simple web service
======================
1. Create server side Java code: 

    // SimpleCrypto.java
    // On the server side 

    public class SimpleCrypto {

          public int caeser(int c) { return c + 3 % 26; }
    }

2. Create server side deployment descriptors. The following deployment
    descriptor defines the web service scope as "application". This scope
    means that the object will be created once and shared by all users.
   The scope value may be changed to "session" or "request". An object
   with request scope is created before each call and destroyed after each
   call. An object with session scope is associated with a particular client.
   When using session scope, your java client will contain the following 
   code. This tells the client to send along a cookie with each request.
   The cookie is used to distinguish between different clients.

                   SomeWSServiceLocator loc = new SomeWSServiceLocator();
                   // maintain session
                   loc.setMaintainSession(true);

Here is the deployment descriptor for an application object.

deploy.wsdd

<deployment xmlns="http://xml.apache.org/axis/wsdd/"
            xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">
 <service name="CaeserService" provider="java:RPC">
  <parameter name="scope" value="application"/>
  <parameter name="className" value="SimpleCrypto"/>
  <parameter name="allowedMethods" value="*"/>
 </service>
</deployment>

Here is an undeploy descriptor.

undeploy.wsdd

<undeployment xmlns="http://xml.apache.org/axis/wsdd/">
 <service name="CaeserService"/>
</undeployment>

3. Copy all .class files to C:\Tomcat 5.5\webapps\axis\WEB-INF\classes.

4. Run adminclient deploy.wsdd

5. When done run adminclient undeploy.wsdd.

If you make any changes to the deployment descriptor you may have to stop
and then restart Tomcat for testing.

III. On the client
===========

1. Visit http://localhost:8080/axis/servlet/AxisServlet
    and save  the wsdl document associated with CaeserService.

2. Place this file on the client side. When writing a microsoft client 
    you will need to change the extension from ".xml" to ".wsdl".

IV. Client side programming in Java
========================
 
1. Run wsdl2java CaeserService.xml.

2. Look over the new directory and examine the Java source code
    generated.

// Java Client directory 

D:\McCarthy\www\95-804\examples\caeser\client>tree /f
Folder PATH listing
Volume serial number is 71FAE346 BA17:BF69
D:.
¦   CaeserClient.class
¦   CaeserClient.java
¦   CaeserService.xml
¦
+---localhost
    +---axis
        +---services
            +---CaeserService
                    CaeserServiceSoapBindingStub.class
                    CaeserServiceSoapBindingStub.java
                    SimpleCrypto.class
                    SimpleCrypto.java
                    SimpleCryptoService.class
                    SimpleCryptoService.java
                    SimpleCryptoServiceLocator.class
                    SimpleCryptoServiceLocator.java


3. Write a client in Java.

	import localhost.axis.services.CaeserService.*;

	public class CaeserClient {

	    public static void main(String args[]) throws Exception {
   
  	        SimpleCryptoServiceLocator loc = new SimpleCryptoServiceLocator();
   	        SimpleCrypto s = loc.getCaeserService();

                          int c = s.caeser(5);

                          System.out.println(c);
    }
}

V. Client side programming in C#
=======================

1. Run wsdl CaeserService.wsdl  (note change in extension)

2. Look over the new ".cs" file and examine the source code.
    The file is named SimpleCryptoService.cs

3. Compile this into a library.
    csc -t:library SimpleCryptoService.cs
    producing a SimpleCryptoService.dll

4. Write a C# client.

using System;
public class MyClient {
   public static void Main() {
        SimpleCryptoService crypto = new SimpleCryptoService();
        int c = crypto.caeser(65);
        Console.WriteLine(c);
   }
}
Compile with 
csc -r:SimpleCryptoService.dll Client.cs

VI. Watching the SOAP interactions
======================
1. Run tcpmon from any directory.

2. The client contacts 7070 (proxy code must be changed to 7070) and tcpmon visits 8080 where 
    Tomcat/Axis is listening