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Handling XML Documents in a Web Service

Chapter 5, specifically the section entitled  Use XML Judiciously  on page 194,

which provides guidelines on this issue. Following these guidelines may help mini 

mize the performance overhead that comes with passing XML documents through

workflow stages. 

Also, when deciding on an approach, keep in mind the costs involved for

using XML and weigh them along with the recommendations on parsing, valida 

tion, and binding documents to Java objects. See Chapter 4 for a discussion of

these topics.

3.7.5 Using JAXM and SAAJ Technologies

The J2EE platform provides an array of technologies including mandatory tech 

nologies such as JAX RPC and SAAJ and optional technologies such as Java

TM

 API

for XML Messaging (JAXM) that enable message and document exchanges with

SOAP. Each of these J2EE technologies offers a different level of support for

SOAP based messaging and communication. (See Chapter 2 for the discussion on

JAX RPC and SAAJ.) 

An obvious question that arises is: Why not use JAXM or SAAJ technologies

in scenarios where you have to pass XML documents? If you recall:

  SAAJ lets developers deal directly with SOAP messages, and is best suited for 

point to point messaging environments. SAAJ is better for developers who 

want more control over the SOAP messages being exchanged and for develop 

ers using handlers.

  JAXM defines an infrastructure for guaranteed delivery of messages. It pro 

vides a way of sending and receiving XML documents and guaranteeing their 

receipt, and is designed for use cases that involve storing and forwarding XML 

documents and messages. 

SAAJ is considered more useful for advanced developers who thoroughly

know the technology and who must deal directly with SOAP messages. 

Using JAXM for scenarios that require passing XML documents may be a

good choice. Note, though, that JAXM is optional in the J2EE 1.4 platform. As a

result, a service developed with JAXM may not be portable. When you control

both end points of a Web service, it may make more sense to consider using

JAXM.