onfig/${product}/${client}/config.xml will result in
product and
client being resolved on every call. By storing configuration files in a corresponding directory structure, specialized configuration files associated with a specific product and client can be loaded. Thus an application can be made multi-tenant in a transparent way.
This builder class keeps a map with configuration builders for configurations already loaded. The {@code getConfiguration()} method first evaluates thepattern string and checks whether a builder for the resulting file name is available. If yes, it is queried for its configuration. Otherwise, a new file-based configuration builder is created now and initialized.
Configuration of an instance happens in the usual way for configuration builders. A {@link MultiFileBuilderParametersImpl} parameters object isexpected which must contain a file name pattern string and a {@code ConfigurationInterpolator}. Other properties of this parameters object are used to initialize the builders for managed configurations.
@version $Id: MultiFileConfigurationBuilder.java 1624601 2014-09-12 18:04:36Z oheger $
@since 2.0
@param < T> the concrete type of {@code Configuration} objects created by thisbuilder