Named PMF proposal / JDOHelper enhancements
-------------------------------------------
Key: JDO-467
URL: https://issues.apache.org/jira/browse/JDO-467
Project: JDO
Issue Type: New Feature
Components: api2, api2-legacy
Affects Versions: JDO 2 maintenance release 1
Reporter: Matthew T. Adams
>From the email on the expert group & jdo-dev alias:
This is a proposal we discussed on the Fri Feb 23 JDO conf call. Please
review and discuss.
Overview:
Currently, there is no way to bootstrap a JDO implementation completely
externally to the source code. The developer is required to provide at
least a resource name that identifies a java.util.Properties file on the
classpath that can configure a single PMF. This makes deployment in
different environments more challenging than necessary.
Motivation:
* Source code is required to be aware of external configuration:
* In all current JDOHelper.getPersistenceManagerFactory APIs and
* in order to configure listeners.
* Aligns JDO bootstrapping with JPA bootstrapping concepts.
Proposed Solution:
* Introduce new API methods and JDO equivalent of the JPA persistence
unit concepts, including a jdo.xml file that provides for the
configuration of one or more named PMFs.
Details:
* PersistenceManagerFactory additions
/** Returns the persistence unit name of this PMF. It's the JPA
persistence unit name if configured via persistence.xml or the JDO
persistence unit name if configured via javax.jdo.xml. */
public String getName();
* JDOHelper API additions
/** The default name of the JDO configuration file. */
public static final String DEFAULT_JDO_CONFIG_RESOURCE_NAME =
"javax.jdo.xml";
/** The name of the default persistence unit. */
public static final String DEFAULT_PMF_NAME = "default";
/** Gets the PMF named "default" in the resource "javax.jdo.xml" found
via the current ClassLoader. */
public static PersistenceManagerFactory getPersistenceFactoryManager() {
return getPersistenceFactoryManagerByName(DEFAULT_PMF_NAME);
}
/** Gets the PMF named pmfName in the resource "javax.jdo.xml" found via
the current ClassLoader. */
public static PersistenceManagerFactory
getPersistenceManagerFactoryByName(String pmfName) {
return getPersistenceFactoryManagerByName(DEFAULT_PMF_NAME,
DEFAULT_JDO_CONFIG_RESOURCE_NAME);
}
/** Gets the PMF named pmfName in the resource named resourceName found
via the current ClassLoader. */
public static PersistenceManagerFactory
getPersistenceManagerFactoryByName(String pmfName, String resourceName)
{
return getPersistenceFactoryManagerByName(DEFAULT_PMF_NAME,
DEFAULT_JDO_CONFIG_RESOURCE_NAME, getClass().getClassLoader());
}
/** Gets the PMF named pmfName in the resource named resourceName found
via the current ClassLoader. */
public static PersistenceManagerFactory
getPersistenceManagerFactoryByName(String pmfName, String resourceName,
ClassLoader loader) {
// reads resource resourceName via given loader
// configures & returns PMF with the given name
}
* Possibilities for DEFAULT_JDO_CONFIG_RESOURCE_NAME value:
need to determine file name (similar to persistence.xml)
javax.jdo.xml
jdo.xml
...
* Proposal for JDO persistence unit configuration XML file
* Could be more like Spring beans.xml (supporting references, etc.)
* Note: Square brackets indicate optional elements/attributes
<jdo-config>
[<extension> elements wherever appropriate]
<!-- Can use attributes for standardized properties -->
<!-- Can also support vendor-specific attributes and still validate
against schema -->
<persistence-manager-factory
[name="default"] <!-- no name implies only the default PMF,
named "default"; can only be one per file -->
[resource="..."] <!-- convenient for backward compatibility -->
[class="xcalia.ic.jdo.PersistenceManagerFactory"]
[connection-driver="..."]
[connection-url="..."]
[connection-user-name="..."]
[connection-password="..."]
[...]
>
<!-- or XML-friendly <property> elements -->
[<property name="javax.jdo...." value="..."/>]
[<property name="javax.jdo...." value="..."/>]
[<property name="xcalia.ic...." value="..."/>]
[...]
<!-- ...and/or properties in java.util.Properties file format?
overrides <property> elements? -->
<!-- This allows people to continue to use good, old
java.util.Properties format if they want -->
<properties><![CDATA[
javax.jdo....=...
javax.jdo....=...
xcalia.ic....=...
...
]]></properties>
<!-- This provides a way (currently, the only way) to configure
listeners outside of the code -->
<!-- We'd have to address any class loading issues, since we're
only given a class name -->
<!-- These should have javax.jdo.listener.... property &
property value equivalents in order to keep old-fashioned
java.util.Property-formatted values consistent with these values -->
<!-- Method names default to names of corresponding interfaces;
if not present on listener-class, they're a no-op or not even called -->
[<instance-lifecycle-listener
listener-class="my.jdo.InstanceListener"
classes-observed="my.domain.Foo,my.domain.Bar,.."
[static-factory-method="..."]
[pre-attach="preAttach"]
[post-attach="postAttach"]
[pre-store="preStore"]
[...]
/>]
<!-- The <instance-lifecycle-listener> element is sufficient,
but we could provide elements for each of the listener types -->
[<attach-lifecycle-listener
class="..."
[factory-method="..."]
[pre-attach="preAttach"]
[post-attach="postAttach"]
/>]
[...]
<!-- Can optionally include <jdo>, <orm> and <jdoquery> elements
here in order to override annotations, or developer-provided .jdo, .orm,
and/or .jdoquery files (from Erik Bengston) -->
<!-- Can add attribute to <jdo>, <orm>, and <jdoquery> to allow
for the specifiation of another resource or set of resources on the
classpath (from Craig Russell), for example: -->
<jdo
resources="META-INF/production-1;META-INF/production-2;..."/>
</persistence-manager-factory>
</jdo-config>
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
