<xml> </xml>

db4o |

# Alias Interface

Implement this interface when implementing special custom Aliases for classes, packages or namespaces.

For a list of all members of this type, see Alias Members.

public interface Alias

#### Types that implement Alias

Type | Description
--- | ---
TypeAlias | a simple Alias for a single Class or Type, using #equals() on the names in the resolve method.
WildcardAlias | Wildcard Alias functionality to create aliases for packages, namespaces or multiple similar named classes.

#### Remarks

Implement this interface when implementing special custom Aliases for classes, packages or namespaces.
Aliases can be used to persist classes in the running application to different persistent classes in a database file or on a db4o server.
Two simple Alias implementations are supplied along with db4o:
- com.db4o.config.TypeAlias provides an #equals() resolver to match names directly.
- com.db4o.config.WildcardAlias allows simple pattern matching with one single '*' wildcard character.
It is possible to create own complex com.db4o.config.Alias constructs by creating own resolvers that implement the com.db4o.config.Alias interface.
Four examples of concrete usecases:

                        // Creating an Alias for a single class

                Db4o.configure().addAlias(

                  new TypeAlias("com.f1.Pilot", "com.f1.Driver"));

    // Accessing a .NET assembly from a Java package

                Db4o.configure().addAlias(

                  new WildcardAlias(

                    "com.f1.*, F1RaceAssembly",

                    "com.f1.*"));

    // Using a different local .NET assembly

                Db4o.configure().addAlias(

                  new WildcardAlias(

                    "com.f1.*, F1RaceAssembly",

                    "com.f1.*, RaceClient"));

    // Mapping a Java package onto another

                Db4o.configure().addAlias(

                  new WildcardAlias(

                    "com.f1.*",

                    "com.f1.client*"));

Aliases that translate the persistent name of a class to a name that already exists as a persistent name in the database (or on the server) are not permitted and will throw an exception when the database file is opened.
Aliases should be configured before opening a database file or connecting to a server.

#### Requirements

Namespace: com.db4o.config

Assembly: db4o (in db4o.dll)

#### See Also

Alias Members | com.db4o.config Namespace