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Difference between revisions of "EclipseLink/Development/DBWS/oNmMetadata"

(Dynamic Persistent Model Classes)
(Dynamic Persistent Model Classes)
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* an in-memory model of the 'oNm' metadata can be realized into runtime artifacts, including generating persistent model classes.
 
* an in-memory model of the 'oNm' metadata can be realized into runtime artifacts, including generating persistent model classes.
 
* generated persistent model classes must work when mapped simultaneously by both an orm and oxm metadata model. <br/> i.e. a generated class must support the following: a row is retrieved from the database, built into an object and that very same object is serialized to XML (and vice-versa).  
 
* generated persistent model classes must work when mapped simultaneously by both an orm and oxm metadata model. <br/> i.e. a generated class must support the following: a row is retrieved from the database, built into an object and that very same object is serialized to XML (and vice-versa).  
* the existing multiple solutions for dynamic generation of persistent model classes (<code>o.e.p.sdo.helper.DynamicClassWriter</code> and <code>o.e.p.internal.dynamicpersist.BaseEntityClassLoader</code>) is re-factored to a single common solution.
+
* the existing multiple solutions for dynamic generation of persistent model classes (<code>o.e.p.sdo.helper.DynamicClassWriter</code> and <code>o.e.p.internal.dynamicpersist.BaseEntityClassLoader</code>) are re-factored to a single common solution.

Revision as of 15:52, 2 June 2009

Future DBWS work

At some point in the future, DBWS will switch from using 'native' EclipseLink metadata (a.k.a. Project deployment xml) to using 'oxm' and 'orm' (a.k.a JPA-style) metadata formats. In addition to using the new metadata formats, DBWS typically operates without persistent model classes; thus at runtime, a dynamic solution is required for the generation of persistent model classes.

New 'oNm' Metadata

High-level Requirements:

  • as there are no persistent model classes on the classpath, processing the metadata must use only simple scalar objects (Strings, booleans, numbers, etc.) for all capabilities and settings.
  • an in-memory model of the metadata can be read in from an 'oNm.xml' file (or stream, URL, etc.) without persistent model classes on the classpath.
  • an in-memory model of the metadata can be serialized to a file (or stream, URL, etc.) without persistent model classes on the classpath.

Dynamic Persistent Model Classes

High-level Requirements :

  • an in-memory model of the 'oNm' metadata can be realized into runtime artifacts, including generating persistent model classes.
  • generated persistent model classes must work when mapped simultaneously by both an orm and oxm metadata model.
    i.e. a generated class must support the following: a row is retrieved from the database, built into an object and that very same object is serialized to XML (and vice-versa).
  • the existing multiple solutions for dynamic generation of persistent model classes (o.e.p.sdo.helper.DynamicClassWriter and o.e.p.internal.dynamicpersist.BaseEntityClassLoader) are re-factored to a single common solution.

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