Migrating XML applications

Why and when to perform this task

The following step is needed to migrate Version 3.5SE XML applications to supported XML APIs.

Steps for this task

  1. Migrate Version 3.5.x XML applications to supported XML APIs

    If your XML applications use XML for Java API, Version 2.0.x or earlier, you must migrate them to API Version 3.1 or the equivalent open-source version. Although there are inherent performance improvements in later versions of the XML for Java API, you can gain additional performance by explicitly using nonvalidating parsers in application environments where you can trust the data.

    The most significant change is that the TX-compatible APIs are no longer available. The Document API retains the XML manipulation APIs that were in TXDocument, but you must rewrite the following functionality:

    • Creating and loading an XML parser: Use a Java API for XML Processing (JAXP) factory class.
    • Writing out the Document Object Model (DOM) tree: Use a serializer. One drawback to the DOM Level 2 implementation in this level of the XML for Java API is that the grammar (DTD or schema) is no longer a node in the DOM tree, so you cannot write it out. As a result, only external grammars are recommended. You can query the system ID of the root element and use it to retrieve the name from the statement. After the tree is written to an XML file, you can read the file as text and insert a statement.

    Note: In addition to the XML API changes, it is important to understand that J2EE Version 1.3 mandates the use of JAXP 1.1, DOM Version 2, and SAX Version 2. JAXP Version 1.2, DOM Version 3, and SAX Version 3 are not allowed in products that are compliant with the J2EE Version 1.3 specification. This prohibition exists because the newer versions were experimental at the time of the J2EE Version 1.3 specification. Because WebSphere Application Server is compliant with the J2EE Version 1.3 specification, WebSphere Application Server has support for JAXP Version 1.1, DOM Version 2 and SAX Version 2 only.

    To migrate a Version 4.0.1 or higher XML application, you must only recompile it to the higher level.


Related concepts
Migrating



Searchable topic ID:   tinsappxmlmigz
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
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