Here is a step-by-step tutorial explaining the quickest and easiest way to expose a plain old java object (POJO) as a web service.  This example uses jboss’s new web services stack (JBossWS-1.0.2.GA).  With this method you can quickly convert any java object into a web service.  For example, you could expose data access objects to a front-side client such as flex.  Best of all, no coding and extremely little configuration is needed to make the conversion from POJO to web service!

 Here is what you need:

1. at least jboss-4.0.4GA
2. with EJB3 enabled (support for annotations)
3. and includes jbossws.sar

Here is the POJO:

package com.squidpower.webservice;

public class ExampleWebService {

       public String echo(String input) {
          return input;
       }

}

How to modify the POJO to be a Web Service:

import javax.jws.WebMethod;
import javax.jws.WebService;
…
@WebService
public class ExampleWebService {
…
@WebMethod
public String echo(String input) {
…

How to deploy the Web Service (lines needed in web.xml file):

 
    ExampleWebService 
    com.squidpower.webservice.ExampleWebService 
   
 
    ExampleWebService 
    /ExampleWebService/*
 

How to access the wsdl:

http://{servername}/{webapp-context-path}/ExampleWebService?wsdl

Notes:

1. To consume the web service the client will need the uri to the wsdl
2. The return type of a web method can be
 a. any primitive type (String, int, etc.)
 b. a java bean containg primitive types with getters or as public fields
 c. arrays of these
3. Limitation: The following types are ignored and will need to be converted to arrays
 a. Collections
 b. Maps