Service providing apparatus, service providing method, and program

A service providing method for advertising first service description on a network and providing a first service associated with the first service description, comprising:

• preparing a definition table to define a condition on which a function of the first service is extended utilizing a second service associated with second service description and a method of calling the second service;
• searching the network for the second service which satisfies the condition referring to the definition table;
• updating the first service description based on the second service description associated with the searched second service;
• advertising service description of the updated first service on the network;
• calling the second service in accordance with the calling method, in response to a service request based on the service description of the advertised first service;
• receiving a response from the called second service;
• and
• generating a response to the service request based on the response from the received second service.

A program stored in a computer readable medium for advertising first service description on a network and providing a first service associated with the first service description, the program comprising:

• means for instructing a computer to store a definition table to define a condition on which a function of the first service is extended utilizing a second service associated with second service description and a method of calling the second service;
• means for instructing the computer to search the network for the second service which satisfies the condition referring to the definition table;
• means for instructing the computer to update the first service description based on the second service description associated with the searched second service;
• means for instructing the computer to advertise service description of the updated first service on the network;
• means for instructing the computer to call the second service in accordance with the calling method, in response to a service request based on the service description of the advertised first service;
• means for instructing the computer to receive a response from the called second service;
• and
• means for instructing the computer to generate a response to the service request based on the response from the received second service.