How To Create a Storage Object

In BERSERK two storage object are used: one to read BERSERK's filters, chains and services defitions, and another to handle application's domain data. Obviously they can be instances of the same class, or even the same instance (if following the Singleton design pattern).

BERSERK's has three logic-layer configuration objects. As stated before, BERSERK follows a highly generic aproach, providing interfaces to it's components, without exception, allowing users and developers to implement their own version.

All that a storage object does is translating a persistent configuration (from any support) to a logic-layer configuration object, following the Data Access Object (DAO) design pattern. Thus, in order to create a storage object, the following interfaces must be implemented:

public interface IPersistentFilterDefinition extends IStorageObject
{
	public abstract IFilterDefinition readByName(String name) throws StorageException;	
}

public interface IPersistentFilterChain extends IStorageObject
{
	public abstract IFilterChain readByName(String name) throws StorageException;
}

public interface IPersistentServiceDefinition extends IStorageObject
{
	public abstract IServiceDefinition readByName(String name) throws StorageException;
}

Those methods are responsible for reading each object by it's name. The underlaying implementation is up to the developer. For an example of two implemetations, please read BERSERK's code.

If you need to store BERSERK's configuration in another way, you must implement your own storage layer.

the DAO

BERSERK's logic-layer access a DAO to obtain the needed configurations. This DAO is specified in berserk.properties file.

Again, any DAO must implement the following interface in order to be used by BERSERK:

public interface IStorageBroker
{
	public IPersistentFilterDefinition getIPersistentFilterDefinition();
	public IPersistentServiceDefinition getIPersistentServiceDefinition();
	public IPersistentFilterChain getIPersistentFilterChain();	
}

The return objects are the storage-layer definitions, described above.

At this point, you can edit berserk.properties and use the recently created DAO. BERSERK will callback the implemented methods and use the desired storage.

Please remember that BERSERK does not obligate the use of files to read it's configurations. Arbitrary data streams can be used as long as there is a DAO that translates them to the definitions objects.