In some case the developer of a service does not expect that there will be several implementations for his service. Therefore he does not create an interface. In this case the configuration looks like this:

<key>org.exoplatform.services.database.jdbc.DBSchemaCreator</key>

<type>org.exoplatform.services.database.jdbc.DBSchemaCreator</type>

The key and type tags contain equally the qualified class name.