Uniform access to and interchange between objects employing a plurality of access methods

• US 6,182,155 B1
• Filed: 01/02/1998
• Issued: 01/30/2001
• Est. Priority Date: 05/09/1997
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Thomson, Brian Ward, Cheng, Michael
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): COURTENAY III, ST JOHN
• Application Number:
  US09/002,362
• Time in Patent Office: 1,124 Days
• Field of Search: 709/300-305, 709/200-253, 709/310, 709/315, 709/316, 709/330, 395/701-710, 717/1
• US Class Current: 719/315
• CPC Class Codes: G06F 9/548 Object oriented; Remote method invocation [RMI] non-remote method invocation G06F9/449

Abstract

Uniform access to and interchange between objects with use in any environment that supports interface composition through interface inheritance and implementation inheritance from a common base class is provided. Proxies are used to provide both cross-language and remote access to objects. The proxies and the local implementations for objects share a common set of interface base classes, so that the interface of a proxy for an object is indistinguishable from a similar interface of the actual implementation. Each proxy is taught how to deal with call paramters that are proxies of the other kind. A roster of language identifiers is developed, and a method is added to each object implementation which, when called, checks whether it matches the language that the object implementation is written in. If so, it returns a direct pointer to the object implementation. Common client coding can then be used to deal with both same language and cross-language calls.

Claims

1. A mechanism for providing a client access to implementation objects in a multi-language computing environment supporting interface composition through inheritance and implementation inheritance from common base classes, said mechanism comprising:

a pure interface base class adapted for generating a hierarchy of pure interface classes containing only method implementations and instance data common to proxies and implementations;

a means for directly accessing an implementation object in response to a user access request on a local same-language implementation object, said implementation inheriting from the pure interface class hierarchy; and

a means for generating a first proxy object in response to a user access request on a local cross-language implementation object, said first proxy object inheriting from the pure interface class hierarchy;

wherein said mechanism provides said client with apparently transparent access to said implementation objects.

2. The mechanism according to claim 1, further comprising a means for generating a language-independent token representing a cross-language implementation object where the user access request is to a local cross-language implementation object;

wherein the means for generating the first proxy object is adapted for providing in said first proxy, a pointer to said token.

3. The mechanism according to claim 1, further comprising a means for generating a broker object having methods for encapsulating the user access request as a transmissible message where the user access request is to a remote implementation object;

wherein the means for generating the first proxy object is adapted for providing in said first proxy, a pointer to said broker object.

4. The mechanism according to claim 1, wherein the pure interface base class is further adapted for generating in said hierarchy of pure interface classes, at least one class containing instance data to refer to a language-independent token representing a cross-language implementation object.

5. The mechanism according to claim 1, wherein the pure interface base class is further adapted for generating in said hierarchy of pure interface classes, at least one class containing method implementations for encapsulating the user access request as a transmissible message.

6. A mechanism for providing a client access to implementation objects in a distributed computing environment supporting interface composition through inheritance and implementation inheritance from common base classes, said mechanism comprising:

a means for directly accessing implementation objects in response to user access requests on local same-language implementation objects;

a means for generating proxy objects pointing to language-independent tokens representing cross-language implementation objects in response to user access requests on local cross-language implementation objects;

a means for generating proxy objects having methods for encapsulating user access requests as transmissible messages in response to user access requests on remote implementation objects;

each said directly accessing and each said generating means presenting identical interfaces to the client to thereby provide said client with apparently transparent access to said implementation objects.

7. The mechanism according to claim 6, each said directly accessing means and each said generating means further comprising:

a pure interface base class adapted for generating a hierarchy of pure interface classes containing only method implementations and instance data common to proxy objects and implementation objects.