[[Jakarta_XML_Web_Services_Tools]]
= Jakarta XML Web Services Tools

The Jakarta XML Web Services tools provided by JBossWS can be used in a variety of ways.
First we will look at server-side development strategies, and then
proceed to the client.

[[server-side]]
== Server side

When developing a Web Service Endpoint (the server-side) you have the
option of starting from Java ( _bottom-up development_), or from the
abstact contract (WSDL) that defines your service ( _top-down
development_). If this is a new service (no existing contract), the
bottom-up approach is the fastest route; you only need to add a few
annotations to your classes to get a service up and running. However, if
you are developing a service with an already defined contract, it is far
simpler to use the top-down approach, since the provided tool will
generate the annotated code for you.

Bottom-up use cases:

* Exposing an already existing Jakarta Enterprise Beans 3 bean as a Web Service
* Providing a new service, and you want the contract to be generated for
you

Top-down use cases:

* Replacing the implementation of an existing Web Service, and you can't
break compatibility with older clients
* Exposing a service that conforms to a contract specified by a third
party (e.g. a vender that calls you back using an already defined
protocol).
* Creating a service that adheres to the XML Schema and WSDL you
developed by hand up front

The following Jakarta XML Web Services command line tools are included in JBossWS:

[cols=",",options="header"]
|=======================================================================
|Command |Description

|wsprovide |Generates Jakarta XML Web Services portable artifacts, and provides the
abstract contract. Used for bottom-up development.

|wsconsume |Consumes the abstract contract (WSDL and Schema files), and
produces artifacts for both a server and client. Used for top-down and
client development
|=======================================================================

[[bottom-up-using-wsprovide]]
=== Bottom-Up (Using wsprovide)

The bottom-up strategy involves developing the Java code for your
service, and then annotating it using Jakarta XML Web Services annotations. These
annotations can be used to customize the contract that is generated for
your service. For example, you can change the operation name to map to
anything you like. However, all of the annotations have sensible
defaults, so only the @WebService annotation is required.

This can be as simple as creating a single class:

[source,java,options="nowrap"]
----
package echo;
 
@javax.jws.WebService
public class Echo
{
   public String echo(String input)
   {
      return input;
   }
}
----

A JSE or Jakarta Enterprise Beans 3 deployment can be built using this class, and it is the
only Java code needed to deploy on JBossWS. The WSDL, and all other Java
artifacts called "wrapper classes" will be generated for you at deploy
time. This actually goes beyond the Jakarta XML Web Services specification, which requires
that wrapper classes be generated using an offline tool. The reason for
this requirement is purely a vender implementation problem, and since we
do not believe in burdening a developer with a bunch of additional
steps, we generate these as well. However, if you want your deployment
to be portable to other application servers, you will unfortunately need
to use a tool and add the generated classes to your deployment.

This is the primary purpose of the _wsprovide_ tool, to generate
portable Jakarta XML Web Services artifacts. Additionally, it can be used to "provide" the
abstract contract (WSDL file) for your service. This can be obtained by
invoking _wsprovide_ using the "-w" option:

....
$ javac -d . -classpath jboss-jaxws.jar Echo.java
$ wsprovide -w echo.Echo
Generating WSDL:
EchoService.wsdl
Writing Classes:
echo/jaxws/Echo.class
echo/jaxws/EchoResponse.class
....

Inspecting the WSDL reveals a service called _EchoService_:

[source,xml,options="nowrap"]
----
<service name='EchoService'>
 <port binding='tns:EchoBinding' name='EchoPort'>
  <soap:address location='REPLACE_WITH_ACTUAL_URL'/>
 </port>
</service>
----

As expected, this service defines one operation, " _echo_":

[source,xml,options="nowrap"]
----
<portType name='Echo'>
 <operation name='echo' parameterOrder='echo'>
  <input message='tns:Echo_echo'/>
  <output message='tns:Echo_echoResponse'/>
 </operation>
</portType>
----

[NOTE]

Remember that when deploying on JBossWS you do not need to run this
tool. You only need it for generating portable artifacts and/or the
abstract contract for your service.

Let's create a POJO endpoint for deployment on WildFly. A simple
_web.xml_ needs to be created:

[source,xml,options="nowrap"]
----
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
  version="2.4">
 
  <servlet>
    <servlet-name>Echo</servlet-name>
    <servlet-class>echo.Echo</servlet-class>
  </servlet>
 
  <servlet-mapping>
    <servlet-name>Echo</servlet-name>
    <url-pattern>/Echo</url-pattern>
  </servlet-mapping>
</web-app>
----

The _web.xml_ and the single class can now be used to create a war:

....
$ mkdir -p WEB-INF/classes
$ cp -rp echo WEB-INF/classes/
$ cp web.xml WEB-INF
$ jar cvf echo.war WEB-INF
added manifest
adding: WEB-INF/(in = 0) (out= 0)(stored 0%)
adding: WEB-INF/classes/(in = 0) (out= 0)(stored 0%)
adding: WEB-INF/classes/echo/(in = 0) (out= 0)(stored 0%)
adding: WEB-INF/classes/echo/Echo.class(in = 340) (out= 247)(deflated 27%)
adding: WEB-INF/web.xml(in = 576) (out= 271)(deflated 52%)
....

The war can then be deployed to the JBoss Application Server.The war can
then be deployed to the JBoss Application Server; this will internally
invoke wsprovide, which will generate the WSDL. If deployment was
successful, and you are using the default settings, it should be
available in the server management console.

For a portable Jakarta XML Web Services deployment, the wrapper classes generated earlier
could be added to the deployment.

[[top-down-using-wsconsume]]
=== Top-Down (Using wsconsume)

The top-down development strategy begins with the abstract contract for
the service, which includes the WSDL file and zero or more schema files.
The _wsconsume_ tool is then used to consume this contract, and produce
annotated Java classes (and optionally sources) that define it.

[NOTE]

wsconsume may have problems with symlinks on Unix systems

Using the WSDL file from the bottom-up example, a new Java
implementation that adheres to this service can be generated. The "-k"
option is passed to _wsconsume_ to preserve the Java source files that
are generated, instead of providing just classes:

....
$ wsconsume -k EchoService.wsdl
echo/Echo.java
echo/EchoResponse.java
echo/EchoService.java
echo/Echo_Type.java
echo/ObjectFactory.java
echo/package-info.java
echo/Echo.java
echo/EchoResponse.java
echo/EchoService.java
echo/Echo_Type.java
echo/ObjectFactory.java
echo/package-info.java
....

The following table shows the purpose of each generated file:

[cols=",",options="header"]
|======================================================
|File |Purpose
|Echo.java |Service Endpoint Interface
|Echo_Type.java |Wrapper bean for request message
|EchoResponse.java |Wrapper bean for response message
|ObjectFactory.java |Jakarta XML Binding XML Registry
|package-info.java |Holder for Jakarta XML Binding package annotations
|EchoService.java |Used only by Jakarta XML Web Services clients
|======================================================

Examining the Service Endpoint Interface reveals annotations that are
more explicit than in the class written by hand in the bottom-up
example, however, these evaluate to the same contract:

[source,java,options="nowrap"]
----
@WebService(name = "Echo", targetNamespace = "http://echo/")
public interface Echo {
    @WebMethod
    @WebResult(targetNamespace = "")
    @RequestWrapper(localName = "echo", targetNamespace = "http://echo/", className = "echo.Echo_Type")
    @ResponseWrapper(localName = "echoResponse", targetNamespace = "http://echo/", className = "echo.EchoResponse")
    public String echo(
        @WebParam(name = "arg0", targetNamespace = "")
        String arg0);
 
}
----

The only missing piece (besides for packaging) is the implementation
class, which can now be written, using the above interface.

[source,java,options="nowrap"]
----
package echo;
 
@javax.jws.WebService(endpointInterface="echo.Echo")
public class EchoImpl implements Echo
{
   public String echo(String arg0)
   {
      return arg0;
   }
}
----

[[client-side]]
== Client Side

Before going to detail on the client-side it is important to understand
the decoupling concept that is central to Web Services. Web Services are
not the best fit for internal RPC, even though they can be used in this
way. There are much better technologies for this (CORBA, and RMI for
example). Web Services were designed specifically for interoperable
coarse-grained correspondence. There is no expectation or guarantee that
any party participating in a Web Service interaction will be at any
particular location, running on any particular OS, or written in any
particular programming language. So because of this, it is important to
clearly separate client and server implementations. The only thing they
should have in common is the abstract contract definition. If, for
whatever reason, your software does not adhere to this principal, then
you should not be using Web Services. For the above reasons, the
*_recommended methodology for developing a client is_* to follow *_the
top-down approach_* , even if the client is running on the same server.

Let's repeat the process of the top-down section, although using the
deployed WSDL, instead of the one generated offline by _wsprovide_. The
reason why we do this is just to get the right value for soap:address.
This value must be computed at deploy time, since it is based on
container configuration specifics. You could of course edit the WSDL
file yourself, although you need to ensure that the path is correct.

Offline version:

[source,xml,options="nowrap"]
----
<service name='EchoService'>
  <port binding='tns:EchoBinding' name='EchoPort'>
   <soap:address location='REPLACE_WITH_ACTUAL_URL'/>
  </port>
</service>
----

Online version:

[source,xml,options="nowrap"]
----
<service name="EchoService">
  <port binding="tns:EchoBinding" name="EchoPort">
    <soap:address location="http://localhost.localdomain:8080/echo/Echo"/>
  </port>
</service>
----

Using the online deployed version with _wsconsume_:

....
$ wsconsume -k http://localhost:8080/echo/Echo?wsdl
echo/Echo.java
echo/EchoResponse.java
echo/EchoService.java
echo/Echo_Type.java
echo/ObjectFactory.java
echo/package-info.java
echo/Echo.java
echo/EchoResponse.java
echo/EchoService.java
echo/Echo_Type.java
echo/ObjectFactory.java
echo/package-info.java
....

The one class that was not examined in the top-down section, was
`EchoService.java`. Notice how it stores the location the WSDL was
obtained from.

[source,java,options="nowrap"]
----
@WebServiceClient(name = "EchoService", targetNamespace = "http://echo/", wsdlLocation = "http://localhost:8080/echo/Echo?wsdl")
public class EchoService extends Service
{
    private final static URL ECHOSERVICE_WSDL_LOCATION;
 
    static {
        URL url = null;
        try
        {
           url = new URL("http://localhost:8080/echo/Echo?wsdl");
        }
        catch (MalformedURLException e)
        {
           e.printStackTrace();
        }
        ECHOSERVICE_WSDL_LOCATION = url;
    }
 
    public EchoService(URL wsdlLocation, QName serviceName)
    {
         super(wsdlLocation, serviceName);
    }
 
    public EchoService()
    {
         super(ECHOSERVICE_WSDL_LOCATION, new QName("http://echo/", "EchoService"));
    }
 
    @WebEndpoint(name = "EchoPort")
    public Echo getEchoPort()
    {
         return (Echo)super.getPort(new QName("http://echo/", "EchoPort"), Echo.class);
    }
}
----

As you can see, this generated class extends the main client entry point
in Jakarta XML Web Services, `javax.xml.ws.Service`. While you can use `Service` directly,
this is far simpler since it provides the configuration info for you.
The only method we really care about is the `getEchoPort()` method,
which returns an instance of our Service Endpoint Interface. Any WS
operation can then be called by just invoking a method on the returned
interface.

[NOTE]

It's not recommended to refer to a remote WSDL URL in a production
application. This causes network I/O every time you instantiate the
Service Object. Instead, use the tool on a saved local copy, or use the
URL version of the constructor to provide a new WSDL location.

All that is left to do, is write and compile the client:

[source,java,options="nowrap"]
----
import echo.*;
 
public class EchoClient
{
   public static void main(String args[])
   {
      if (args.length != 1)
      {
          System.err.println("usage: EchoClient <message>");
          System.exit(1);
      }
 
      EchoService service = new EchoService();
      Echo echo = service.getEchoPort();
      System.out.println("Server said: " + echo.echo(args0));
   }
}
----

It is easy to change the endpoint address of your operation at runtime,
setting the _ENDPOINT_ADDRESS_PROPERTY_ as shown below:

[source,java,options="nowrap"]
----
EchoService service = new EchoService();
      Echo echo = service.getEchoPort();
 
      /* Set NEW Endpoint Location */
      String endpointURL = "http://NEW_ENDPOINT_URL";
      BindingProvider bp = (BindingProvider)echo;
      bp.getRequestContext().put(BindingProvider.ENDPOINT_ADDRESS_PROPERTY, endpointURL);
 
      System.out.println("Server said: " + echo.echo(args0));
----


include::wsconsume.adoc[]

include::wsprovide.adoc[]
