Using design pattern and generic programming in system refactoring

System refactoring is the process of changing a software system in such a way that it does not alter the external behavior of the code but improve its internal structure.Design patterns are the descriptions of communicating objects and classes that are customized to solve a general design problem in a particular context.Generic programming is a paradigm that focuses on abstracting types to a narrow collection of functional requirements and on implementing algorithms in terms of these requirements.Taking refactoring a data collection system as an example,design pattern is applied to its design,before generic programming is used in implementation.An in-depth dis-cussion about using these two techniques to system refactoring is presented.