CSC/ECE 517 Fall 2009/wiki 1a 7a HJ

Definition of code refactoring

According Wikipedia : "Code refactoring is the process of changing a program's internal structure without modifying its external functional behavior or existing functionality with the goals of readability, maintainability, performance, extensibility and simplicity."

Goals of refactoring

Refactoring is motivated by the difficulty of adding new functionality to a program. or fixing a bug in it.

As we said berfore, after code refactoring, the program does the the exact same thing it did before.

The differences are that the new code:

1) is easier to read and so to understand

2) contains less duplication

3) is less complex

4) is more flexible towards future changes

5) could lead to a faster compilation time

Common Refactorings for JAVA

Here is a list of some examples of refactoring. For further information, the reader please refer to Lecture 3 of CSC 517 of Dr. Gehringer and to the section 2.1.2.

1) Rename a) Methods b) Fields c) Packages d) Projects e) Parameters f) Local Variables

2) Encapsulate Field

3) Pull up a) Field b) Method

4) Push down a) Field b) Method

5) Extract from an Expression a) Method b) Constant c) Local Variables

6) Change Method Signature