A Flexible Integration Framework for Software

Current trend of constructing new systems from collections of pre-existing third-party tools and commercial off-the-shelf (COTS) software presents serious challenges to existing integration technology. The unique constraints of third-party software (such as inadequacy of integration interfaces, closeness of the system architecture, and lack of access to the source code), the interactive, autonomous nature of most of today's software applications, and the increasingly emphasized new integration requirements (such as broad framework applicability, flexible integration, strong support for system evolution, component reusability, and end-user programmability) are among the major reasons for causing this difficulty. This dissertation presents a flexible integration framework which has general applicability for pre-existing tools and COTS software, supports users to easily change the way software interact with each other (thus suppofting flexible integration, system evolution and component reusability), and is easily programmable by the end-users. The framework consists of four major substrates: 1) A dynamic interoperability model which separates interaction relationship from tools and provides implicit communication and dynamic binding for managing independence and flexibility of the interaction relationship. This fonns the conceptual base for our framework; 2) A black box integration approach called implicit tool encapsulation which extends the traditional integration interfaces to graphical user interface and system interface, and uses passive, implicit, system-centered mechanism for tool encapsulation. This offers a new way for tool integration and it can be applied to a much wider array of tools than current methods; 3) A general methodology for tool integration which is derived from the dynamic interoperability model and implicit tool encapsulation approach, and is applicable for pre-existing third-party tool and COTS software; 4) A language called Tool Integration Language (TIL) which has the capability of accessing the functionality of tools through their user interface as well as other interfaces, and it can be used to describe the user's interaction between tools and the interaction between tools themselves. This provides necessary integration language for our framework and de-couples the integration policy from the mechanism. A prototype system Tool Integration Server System (TISS) has been constructed which supports TIL glue code generation and execution, and provides flexible integration mechanisms for our framework. By instantiating the general integration methodology with TIL language and TISS system, it generates a flexible and practical integration approach for integrating pre-existing, GUI-based, interactive tools without any source code modification. Chapter