jax-rpc vs jax-ws

JAX-WS

JAX-WS 2.0 is the successor of JAX-RPC 1.1 - the Java API for XML-based Web services. If possible, JAX-WS should be used instead as it is based on the most recent industry standards.

What remains the same?

Before we itemize the differences between JAX-RPC 1.1 and JAX-WS 2.0, we should first discuss what is the same.

* JAX-WS still supports SOAP 1.1 over HTTP 1.1, so interoperability will not be affected. The same messages can still flow across the wire.

* JAX-WS still supports WSDL 1.1, so what you've learned about that specification is still useful. A WSDL 2.0 specification is nearing completion, but it was still in the works at the time that JAX-WS 2.0 was finalized.

What is different?

Jax-RPC is generated at static time where as Jax-ws is dynamic

* SOAP 1.2

JAX-RPC and JAX-WS support SOAP 1.1. JAX-WS also supports SOAP 1.2.

* XML/HTTP

The WSDL 1.1 specification defined an HTTP binding, which is a means by which you can send XML messages over HTTP without SOAP. JAX-RPC ignored the HTTP binding. JAX-WS adds support for it.

* WS-I's Basic Profiles

JAX-RPC supports WS-I's Basic Profile (BP) version 1.0. JAX-WS supports BP 1.1. (WS-I is the Web services interoperability organization.)

* New Java features

o JAX-RPC maps to Java 1.4. JAX-WS maps to Java 5.0. JAX-WS relies on many of the features new in Java 5.0.

o Java EE 5, the successor to J2EE 1.4, adds support for JAX-WS, but it also retains support for JAX-RPC, which could be confusing to today's Web services novices.

* The data mapping model

o JAX-RPC has its own data mapping model, which covers about 90 percent of all schema types. Those that it does not cover are mapped to javax.xml.soap.SOAPElement.

o JAX-WS's data mapping model is JAXB. JAXB promises mappings for all XML schemas.

* The interface mapping model

JAX-WS's basic interface mapping model is not extensively different from JAX-RPC's; however:

o JAX-WS's model makes use of new Java 5.0 features.

o JAX-WS's model introduces asynchronous functionality.

* The dynamic programming model

o JAX-WS's dynamic client model is quite different from JAX-RPC's. Many of the changes acknowledge industry needs:

+ It introduces message-oriented functionality.

+ It introduces dynamic asynchronous functionality.

o JAX-WS also adds a dynamic server model, which JAX-RPC does not have.

* MTOM (Message Transmission Optimization Mechanism)

JAX-WS, via JAXB, adds support for MTOM, the new attachment specification. Microsoft never bought into the SOAP with Attachments specification; but it appears that everyone supports MTOM, so attachment interoperability should become a reality.

* The handler model

o The handler model has changed quite a bit from JAX-RPC to JAX-WS.

o JAX-RPC handlers rely on SAAJ 1.2. JAX-WS handlers rely on the new SAAJ 1.3 specification.