Providing default instances of factory configurations

You can create default instances of your factory configuration when using the OSGi metatype services. One of the design principles of Liberty is to keep user configuration as small and simple as possible. By providing default instances of your factory configurations, you don't have to add these configurations into the server.xml file.

Example

To provide a default configuration instance, you need to include it in an XML file within your OSGi bundle, and reference the file by using the IBM-Default-Config header in the bundle manifest file as follows:

IBM-Default-Config: OSGI-INF/wlp/defaultInstances.xml

The format of the XML file is the same as that of the server.xml file, but you must specify a unique identifier for each instance. For example, to provide a default instance of the teenager configuration that is used in the example on the Single versus multiple configuration instances topic, the defaultInstances.xml file must have the following settings:

<server>
	<teenager id="predefined-teen1" name="Susie" age="19" />
</server>

The default instance is not exposed to users through the configuration schema, and therefore it is not visible in the development tools; however, you can document the instance so that your users can override the individual attributes in their server.xml files as follows:

<teenager id="predefined-teen1" age="13" />

This line of code will override the age attribute of the default instance, but the name attribute remains valid.