ADF User Preferences

ADF Provides extension to standard Java Preferences API and is maintained in MDS Repository. 

You can reference following Javadoc and Blog:

• http://docs.oracle.com/cd/E12839_01/apirefs.1111/e10686/oracle/adf/share/prefs/package-summary.html
• http://blog.whitehorses.nl/2012/07/10/saving-user-preferences-in-oracle-webcenter/

But this does not work in Plain ADF application and you will run into following exception.

oracle.mds.exception.ReadOnlyStoreException: MDS-01273: The operation on the resource /oracle/adf/share/prefs/data/preferences.xml failed because source metadata store mapped to the namespace / DEFAULT is read only.

To resolve this issue, change your application's adf-config.xml file as highlighted below.

<persistence-config>
       <metadata-namespaces>
          <namespace path="/oracle/adf/share/prefs" metadata-store-usage="MAR_TargetRepos"/>
          <namespace path="/persdef" metadata-store-usage="MAR_TargetRepos"/>
       </metadata-namespaces>
       <metadata-store-usages>
          <metadata-store-usage id="MAR_TargetRepos" deploy-target="true" default-cust-store="true">
          </metadata-store-usage>
       </metadata-store-usages>
</persistence-config>