Doug Kohlert's Blog

April 2005 Archives

JAX-RPC 2.0 EA

The new architecture allows for:

Multiple Transports
  - EA currently supports HTTP
Multiple Encodings
  - EA supports XML as text.
  - The next EA will include MTOM/XOP and Fast Infoset
Multiple Protocols
  - EA supports SOAP 1.1
  - The next EA will include SOAP 1.2

The next EA due out before JavaOne will also have a dynamic runtime. This means no more stubs/ties, serializers, deserializers etc. All artifacts generated by the JAX-RPC SI will be 100% portable to other JAX-RPC 2.0 implementations. I will blog about this again when the next release is available.

Arun Gupta has blogged about how the current JAX-RPC 2.0 EA can be deployed ontop of JWSDP 1.5. You can read his blog at: JAX-RPC 2.0 EA on JWSDP 1.5

You can dowload the current EA at: here.

JAX-RPC 2.0 Standard Implementation Early Access

I would like to highlight some of the new features available in this release here.

JAXB data binding
JAXB 2.0 Early Access is also available. JAX-RPC 2.0 uses JAXB for all of its data binding. This means that much more of XML Schema can be handled compared to JAX-RPC 1.1. Although JAXB 2.0 has not completed bindings for all of XML Schema in this release, it will do so by FCS.

You can access the standalone early access of JAXB 2.0 at the JAXB Project on Java.net.

Metadata
Annotations from JSR 181 are used to allow customizations in the mapping from Java to WSDL. Many JAX-RPC 1.X users complained that the SI generated meaningless part names like: String_1. Now developers can customize these names using the WebParam annotation. Of course there are many more customizations available that allow the developer to control most of the mapping to WSDL. Here is an example of an annotated endpoint implementation class.

@WebService(targetNamespace="http://duke.org",  name="AddNumbers")
@SOAPBinding(style=SOAPBinding.Style.RPC, use=SOAPBinding.Use.LITERAL)
public class AddNumbers {
    
   @WebMethod(operationName="add", action="urn:addNumbers")
   @WebResult(name="return")
   public int addNumbers(
            @WebParam(name="num0")int number1, 
            @WebParam(name="num1")int number2) throws RemoteException, AddNumbersException {
        if (number1 < 0 || number2 < 0) {
            throw new AddNumbersException("Negative number cant be added!",
                "Numbers: " + number1 + ", " + number2);
        }
        return number1 + number2;
    }
}

JAXB 2.0 also defines a number of annotations that can be used to customize the mapping of Java types to XML Schema.

Customizations
Customizations allow the developer to customize the mapping from WSDL to Java. For those of you that are familiar with JAXB 1.0 customizations, JAX-RPC customizations will look familiar as they are model after JAXB customizations. In fact, you can embedded JAXB customizations within a JAX-RPC customization giving you the ability to customize both WSDL and XML Schema.

Improved Handler Framework
JAX-RPC 2.0 allows for the use of both logical and protocol handlers. Protocol handlers have access to the entire message, while logical handlers only have access to the payload of the message. So in the case of a SOAP message a protocol handler can access the entire SOAP envelope, while a logical handler will only have access to the contents of the SOAP body.

Handler chains can now be configured on a per-port, per-protocol, or per-service basis.

Dynamic Client
JAX-RPC 2.0 has added a new Dispatch interface. This interface is the follow on to the 1.1 Call interface. This inteface gives the developer much more control over what is sent over the wire in a web service invocation. It allows the client developers to with either java.lang.transform.Source, javax.xml.soap.SOAPMessage or a JAXB data bound object. The developer can also choose to work with the entire message or just the payload of the message.

Dynamic Server
The Provider interface is provided as a counter part to the Dispatch interface. It allows server developers the same choices as the Dispatch developers do when writing a client.

Asynchronous Clients
Asynchronous clients are now supported on both stubs and the new Dispatch interface. Clients can choose between polling or callback techniques. For example, a standard invocation of a addNumbers operation on a stub would look like:

private void invokeSynchronous() throws RemoteException{
   int number1 = 10;
   int number2 = 20;
        
   System.out.println("\nInvoking synchronous addNumber():");
   int result = port.addNumbers(number1, number2);
   System.out.printf("The result of adding %d and %d is %d\n", number1, number2, result);        
}

Here is the same operation invoke asynchronously using polling.

private void invokeAsyncPoll() throws InterruptedException, ExecutionException{
   int number1 = 10;
   int number2 = 20;

   System.out.println("\nInvoking Asynchronous Polling addNumbersAsync():");
   javax.xml.rpc.Response resp = port.addNumbersAsync(number1, number2);
   Thread.sleep(2000);
   AddNumbersResponse output = resp.get();
   System.out.printf("The result of adding %d and %d is %d\n", number1, number2, output.getReturn());        
}

And here it is using the the callback mechanism.

private void invokeAsyncCallback() throws InterruptedException{
   int number1 = 10;
   int number2 = 20;

   System.out.println("\nInvoking Asynchronous Callback addNumbersAsync():");
   AddNumbersCallbackHandler callbackHandler = new AddNumbersCallbackHandler();
   Future response = port.addNumbersAsync(number1, number2, callbackHandler);
   Thread.sleep(2000);
        
   AddNumbersResponse output = callbackHandler.getResponse();               
   System.out.printf("The result of adding %d and %d is %d\n", number1, number2, output.getReturn());                
}

Please send feedback to the JAXB 2.0 and JAX-RPC 2.0 forum

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