Chapter 3 Service Endpoint Design

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In addition to the WS I protocols, other groups, such as SOAPBuilders

Interoperability group (see 

http://java.sun.com/wsinterop/sb/index.html

),

provide common testing grounds that make it easier to test the interoperability of

various SOAP implementations. This has made it possible for various Web ser 

vices technology vendors to test the interoperability of implementations of their

standards. When you implement your service using technologies that adhere to the

WS I Basic Profile specifications, you are assured that such services are interop 

erable.

Apart from these standards and testing environments, you as the service

developer must design and implement your Web service so that maximum

interoperability is possible. For maximum interoperability, you should keep these

three points in mind:

1. The two messaging styles and bindings supported by WSDL

2. The WS I support for attachments

3. The most effective way to use handlers

WSDL supports two types of messaging styles: 

rpc

 and 

document

. The WSDL

style

 attribute indicates the messaging style. (See Code Example 3.14.) A 

style

attribute set to 

rpc

 indicates a RPC oriented operation, where messages contain

parameters and return values, or function signatures. When the 

style

 attribute is

set to 

document

, it indicates a document oriented operation, one in which mes 

sages contain documents. Each operation style has a different effect on the format

of the body of a SOAP message. 

Along with operation styles, WSDL supports two types of serialization and

deserialization mechanisms: a 

literal

 and an 

encoded

 mechanism. The WSDL

use

 attribute indicates which mechanism is supported. (See Code Example 3.14.)

A 

literal

 value for the 

use

 attribute indicates that the data is formatted according

to the abstract definitions within the WSDL document. The 

encoded

 value means

data is formatted according to the encodings defined in the URI specified by the

encodingStyle

 attribute. Thus, you can choose between an rpc or document style

of message passing and each message can use either a literal or encoded data for 

matting.

E

Because the WS I Basic Profile 1.0, to which J2EE1.4 platform conforms, sup 

ports only literal bindings, you should avoid encoded bindings.