| :_basedir: |
| :_imagesdir: images/ |
| :grid: cols |
| :metadata: |
| |
| [[index]] |
| |
| == Persistence MetaDataanchor:Persistence_MetaData[] |
| |
| All variants of JDO support specification of persistence using XML MetaData. |
| JDO 2.1+ adds on the ability to specify persistence using Java annotations. |
| |
| [[xml]] |
| === XML MetaData |
| |
| JDO expects any XML MetaData to be specified in a file or files in particular positions in the file system. |
| For example, if you have a class _com.mycompany.sample.MyExample_, JDO will look for any of the |
| following files until it finds one (in the order stated) : |
| |
| .... |
| META-INF/package.jdo |
| WEB-INF/package.jdo |
| package.jdo |
| com/package.jdo |
| com/mycompany/package.jdo |
| com/mycompany/sample/package.jdo |
| com/mycompany/sample/MyExample.jdo |
| .... |
| |
| In addition to specifying XML MetaData in a *jdo* file, if defining O/R |
| mapping information you can also split this out into an ORM file. The |
| locations for ORM files are similar in nature to those for JDO files. |
| |
| .... |
| META-INF/package-{mapping}.orm |
| WEB-INF/package-{mapping}.orm |
| package-{mapping}.orm |
| com/package-{mapping}.orm |
| com/mycompany/package-{mapping}.orm |
| com/mycompany/sample/package-{mapping}.orm |
| com/mycompany/sample/MyExample-{mapping}.orm |
| .... |
| |
| where _\{mapping}_ is a property specified by the user and may be |
| "mysql" for ORM information for MySQL datastores, and "oracle" for ORM |
| information for Oracle datastores, and so on. |
| |
| {empty} + |
| |
| |
| [[Annotations]] |
| === Annotations |
| |
| JDO 2.1+ added support for annotations. |
| Classes and fields/properties can be annotated defining the persistence and, optionally, any ORM information. |
| |
