�ݺ�ߣ

AS – Global Business Services

Refactoring

For Programmers
Camilo Lopes

Brazilian Java AS Competency 12/12/08 © 2007 IBM Corporation


Topics to be addressed
 Objective
 Why Refactoring?
 What is Refactoring ?
 Advantage
 When Refactoring
 Tools
 Results
 Example Java
 Questions

© 2007 IBM Corporation
2 Brazilian Java AS Competency 12/12/08


Objective

Assist in the development of system Object Oriented
implements in the Java language that have fall reusability of
code, maintaining hard and the add or adequacy of news
requirement sue a lot of work of engineer Software,
programmer, Analyst System, points that can generate big cost
the project.



Time x Spent

Time
Spent

Picture 1 believe that about 50% of time of an engineer Software is spent with task of maintaining
and comprehension of code.
Fonte: Maia (2004)


Cost x Spent

Cost
Spent

Picture 2 The long of last three decade more of 60% of cost of development of Software of
enterprise was spent with



Why Refactoring?

Refactoring help the become the code
more legible and solve problem of bad
code write



Definition Refactoring

Refactoring is the process of re-structure
the system without change your
functionality (Fowler,2004).



Motive to use Refactoring

 Improve the project Software
 Have a Software easier of comprehension the level
code
 Programmer faster



Advantage

 The technical of refactoring can be applicate in the
development and maintaining of Software;
 Refactoring possibility the add of new functionality of
mode easy averting the re-structure of code;
 With the use of refactoring spent less time possible in
maintaining the level code, improve the legibility and
structure the code.



Tools

 Xrefactoring: the languages compatible are C and Java
this tools possibility the generation of documentation
on format HTML;
 RefactorIT: is a tools to refactoring that can be integrate
in several IDEs.
 Jfactor: is a tools that permit the application automatic
of refactoring the program in Java.



When Refactoring ?

 Code duplicate;
 Method long;
 Comments superfluous;
 Command switch



Results

 Easy in the process of maintaining and
development of Software;
 Can be applicate the any language Oriented
Object;
 Become the Software flexible to add of new
functionality without re-structure of code;
 Maintain the behavior of Software;



Example – Substitute a number literal by constant
symbolic
 Are numbers with value special in system;
 Sometimes are use in more of a place;
 To make the reading and comprehension
 double energiaPotencial(double massa,
double altura{
return massa * 9.81 * altura;
} // code do not refactoring



Code Factored

static final double CONSTANTE_GRAVITACIONAL = 9.81;

double energiaPotencial(double massa, double altura){

return massa * CONSTANTE_GRAVITACIONAL * altura;

}

MECHANICS

declare a constant and attribute a value to number
literal;

find where this number appear;

see if the change can be to do, case positive change the
number by constant;

compile and test.


Questions?!

Thanks!
http://camilolopes.wordpress.com


�ݺ�ߣ

Refactoring

More Related Content

Refactoring