We all talk about the way we do things in our everyday work,
hobbies and home life and recognize repeating patterns all the time.
We see the same thing in programming, when we tell a colleague
how we accomplished a tricky bit of programming so he doesn't have to
recreate it from scratch. We simply recognize effective ways for objects to
communicate while maintaining their own separate existences.
Some useful definitions of design patterns have emerged as the
literature in his field has expanded:
implementation." (Coplien & Schmidt, 1995).
But while it is helpful to draw analogies to architecture, cabinet
making and logic, design patterns are not just about the design of objects, but
about the communication between objects. In fact, we sometimes think of
them as communication patterns. It is the design of simple, but elegant,
methods of communication that makes many design patterns so important.
Design patterns can exist at many levels from very low level specific
solutions to broadly generalized system issues. There are now in fact
hundreds of patterns in the literature. They have been discussed in articles
and at conferences of all levels of granularity. Some are examples which have
wide applicability and a few (Kurata, 1998) solve but a single problem.
It has become apparent that you don't just write a design pattern off
the top of your head. In fact, most such patterns are discovered rather than
written. The process of looking for these patterns is called "pattern mining,"
and is worthy of a book of its own.
The 23 design patterns selected for inclusion in the original Design
Patterns book were ones which had several known applications and which
were on a middle level of generality, where they could easily cross
application areas and encompass several objects.
The authors divided these patterns into three types creational,
structural and behavioral.
flexibility in deciding which objects need to be created for a given case.
We'll be looking at Java versions of these patterns in the chapters that
follow.
hobbies and home life and recognize repeating patterns all the time.
- Sticky buns are like dinner rolls, but I add brown sugar and nut filling to
- Her front garden is like mine, but, in mine I use astilbe.
- This end table is constructed like that one, but in this one, the doors
We see the same thing in programming, when we tell a colleague
how we accomplished a tricky bit of programming so he doesn't have to
recreate it from scratch. We simply recognize effective ways for objects to
communicate while maintaining their own separate existences.
Some useful definitions of design patterns have emerged as the
literature in his field has expanded:
- Design patterns are recurring solutions to design problems you see over
- Design patterns constitute a set of rules describing how to accomplish
- Design patterns focus more on reuse of recurring architectural design
implementation." (Coplien & Schmidt, 1995).
- A pattern addresses a recurring design problem that arises in specific
- Patterns identify and specify abstractions that are above the level of
But while it is helpful to draw analogies to architecture, cabinet
making and logic, design patterns are not just about the design of objects, but
about the communication between objects. In fact, we sometimes think of
them as communication patterns. It is the design of simple, but elegant,
methods of communication that makes many design patterns so important.
Design patterns can exist at many levels from very low level specific
solutions to broadly generalized system issues. There are now in fact
hundreds of patterns in the literature. They have been discussed in articles
and at conferences of all levels of granularity. Some are examples which have
wide applicability and a few (Kurata, 1998) solve but a single problem.
It has become apparent that you don't just write a design pattern off
the top of your head. In fact, most such patterns are discovered rather than
written. The process of looking for these patterns is called "pattern mining,"
and is worthy of a book of its own.
The 23 design patterns selected for inclusion in the original Design
Patterns book were ones which had several known applications and which
were on a middle level of generality, where they could easily cross
application areas and encompass several objects.
The authors divided these patterns into three types creational,
structural and behavioral.
- Creational patterns are ones that create objects for you, rather than
flexibility in deciding which objects need to be created for a given case.
- Structural patterns help you compose groups of objects into larger
- Behavioral patterns help you define the communication between objects
We'll be looking at Java versions of these patterns in the chapters that
follow.
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Posted By م /عوض خليل سيد to Engineering lessons at 10/27/2011 05:20:00 PM
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Eng: Awad Khalil Sayed
Team leader
Mobile:+20104940612
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