The prepackaged subsystem configuration files form part of the core product and shouldn’t be edited.
The prepackaged subsystems are in the <configRoot>/classes/alfresco/subsystems directory.
Each subsystem directory should contain one or more Spring XML bean definition metadata files, with names matching the *-context.xml pattern. These files are loaded by the child application context that belongs to the subsystem instance.
The XML bean definitions can contain placeholders for properties that correspond to configuration parameters of the subsystem. As per standard Spring conventions, these place holders begin with ${ and end with }. In the following example, the value of the ooo.user configuration parameter will be substituted into the bean definition when it’s loaded:
<beanid="userInstallationURI"class="org.alfresco.util.OpenOfficeURI">
<constructor-arg>
<value>${ooo.user}</value>
</constructor-arg>
</bean>
There’s no need to declare a PropertyPlaceholderConfigurer bean. An appropriate one is added into the application context automatically.