If a problem occurs over and over again, a solution to that problem has been used
effectively. That solution is described as a pattern. The design patterns are languageindependent
strategies for solving common object-oriented design problems. When you
make a design, you should know the names of some common solutions. Learning design
patterns is good for people to communicate each other effectively. In fact, you may have
been familiar with some design patterns; you may not use well-known names to describe
them. SUN suggests GOF (Gang of Four—four pioneer guys who wrote a book named
“Design Patterns”- Elements of Reusable Object-Oriented Software), so we use that book
as our guide to describe solutions. Please make you be familiar with these terms and learn
how other people solve the coding problems.
If you want to be a professional Java developer, you should know at least some popular
solutions to coding problems. Such solutions have been proved efficient and effective by
the experienced developers. These solutions are described as so-called design patterns.
Learning design patterns speeds up your experience accumulation in OOA/OOD. Once
you grasped them, you would be benefitted from them for all your life and jump up
yourselves to be a master of designing and developing. Furthermore, you will be able to
use these terms to communicate with your fellows or assessors more effectively.
Many programmers with many years’ experience don’t know design patterns, but as an
Object-Oriented programmer, you have to know them well, especially for new Java
programmers. Actually, when you solved a coding problem, you have used a design
pattern. You may not use a popular name to describe it or may not choose an effective way
to better intellectually control over what you built. Learning how the experienced
developers to solve the coding problems and trying to use them in your project are a best
way to earn your experience and certification.
Remember that learning the design patterns will really change how you design your code;
not only will you be smarter but will you sound a lot smarter, too. The 23 design patterns
by GOF are well known, and more are to be discovered on the way.
There are three well-known types of design patterns.