What are design patterns ?

what are design patterns ?
what is the difference between design patterns and frameword ?
any help would be really appreciated !!

A quick [url http://www.google.com/search?hl=en&q=what+are+design+patterns+%3F+&btnG=Google+Search&meta=] google will bring more answers than you know what to do with.

Similar Messages

Design Patterns in OO-ABAP

Hi Everyone ,
What are design pattern in Object Oriented ABAP.
How will we know that which pattern suits the particular scenario.
Thanks
Sandeep

Hi,
yes its not free, but its really worth the money.
Other abap specific sources:
http://wiki.sdn.sap.com/wiki/display/ABAP/ABAPObjectsDesignPatterns-ModelViewController%28MVC%29
http://www.sdn.sap.com/irj/scn/weblogs;jsessionid=%28J2EE3417200%29ID0796789650DB21029243082976783901End?blog=/pub/wlg/606
/people/marcelo.ramos/blog/2008/04/30/sapmvc-a-new-mvc-for-classical-abap-dynpro
Greetings,
DSP

Design Patterns

Hi,
I am new to these forums.
I know that there are 4 types of J2EE Design Patterns.
1. Fundamental
2. Structural
3. Creational
4. Behavioral.
Hope that's correct. Can anyone plz tell me what's the difference between them?
Also, examples for them. ie; Under which category mentioned above, patterns like Singleton,ServiceLocator,Session facade, DAO,DTO etc fall?
Thanks in advance.

BigDaddyLoveHandles wrote:
Kumaari wrote:
Please give me some explanation in your words.
Thanks in advance.In software engineering, a design pattern is a general reusable solution to a commonly occurring problem in software design. A design pattern is not a finished design that can be transformed directly into code. It is a description or template for how to solve a problem that can be used in many different situations. Object-oriented design patterns typically show relationships and interactions between classes or objects, without specifying the final application classes or objects that are involved. Algorithms are not thought of as design patterns, since they solve computational problems rather than design problems.
Not all software patterns are design patterns. Design patterns deal specifically with problems at the level of software design. Other kinds of patterns, such as architectural patterns, describe problems and solutions that have alternative scopes.
Better?
Brilliant. Bravo sir, bravo

JDBC Design Patterns

Hi All,
I am new to patterns and have started understanding them using the Head First Series.
I would like to know what all design patterns are there in JDBC?
Can i say that JDBC uses a Facade design patterns as it hides the database specific details and provides us a interface which helps us to connect to a database. What other design patterns exist as part of the JDBC?
Request you to clarify my doubts.
Many thanks in advance

I would really appreciate a good discussion on it
rather than any spoon feeding.
A typical JDBC code will appear as follows:
try
/* Load the jdbc-odbc driver
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
// Open a connection to data source
con
=DriverManager.getConnection("jdbc:odbc:DBName","","")
// Get a statement from the connection
Statement stmt = conn.createStatement() ;
// Execute the query
ResultSet rs = stmt.executeQuery( "select * from
table_name" ) ;
1. Is it ok to look into each statement of the above
code snippet in terms of Design Patterns.it's ok, yes. not necessarily appropriate or worthwhile, though
2. How can one dissect each line of the code in terms
of various design patterns?you can't. design patterns exist at a higher level of abstraction than code. 'in terms of' is also disconcertingly vague.
3. Is it correct to conclude that java.sql package
overall uses Abstract Factory Pattern.
As it uses lot of interfaces and implemetation is
provided by the Vendors. yep. that sounds fair enough. not very useful, though
4. Consider a particular package like
java.sql.Statement,java.sql.Blob,java.sql.Connection
etc. is is correct to conclude that
its an example of a Factory Method Pattern as any
client would instantiate. Here the client would be
Statement object,
Creator is Connection Interface and createStatement()
is the factory method.possibly. there's little value in trying to define everything as a "design pattern", though. rather than thinking "oh, they must be using PATTERN X here", think "if I were writing this code, I think PATTERN X would be appropriate". or, more usefully, "is there a pattern that solves this problem?". there isn't, necessarily
5. I am not able to understand if a statement like
Class.forName() should be viewed only in terms of a
programming instruction or
any design patternit's a line of code, nothing more. stop trying to make everything into a pattern. until you realise where patterns are and aren't applicable, you'll never understand them
6. Can "stmt.executeQuery()" can be viewed as A
Strategy Pattern? nope. what makes you think that?
I would really welcome a good discussion on the above
questions.does the discussion have to involve design patterns? you know, of course, that design patterns aren't magic beans, right? I know you've just discovered patterns, and are all excited by them, but seriously, they're only ideas, not Infallible Solutions To All Software Problems ™. the most common mistake people make using design patterns is to see them everywhere, and try to bend every problem to fit a particular pattern
for the record, nobody really views JDBC in terms of patterns. there's little value in viewing existing technologies in those terms, since the most you can "gain" is to have guessed what some other developer did, before.

Design Pattern Names

Started fooling around with some industry-specific software implementations. In one software design document, I came across a reference to an old familiar term "design patterns". This part of the text was describing XML Schema Design Patterns. Below is the first paragraph, which made me laugh :o)
"As with software design, there are design patterns associated with XML Schema design. The most popular XML Schema design patterns are Russian Doll, Salami, Bologna, Venetian Blind and Garden of Eden."
Unlike the GoF, these guys seem to be hungry....
Anybody have any experience implementing the Bologna design pattern?

I agree with dubwai's take on this. These are not design patterns, in my opinion. These are language-specific, very defined, programming algorithms for handling a few typical issues with processsing XML-based data.
To label these as "design patterns" is a bad thing and just another step to adding to the confusion of what an object-oriented design pattern really is.
Moreover, the name of an object-oriented design has a very important role. Care should be taken when naming a design pattern; a name should convey the meaning or intent of the pattern. To call a "design pattern" Salami Slice is a joke, in my opinion.
One of the most important aspects of design patterns is that they are NOT specific, coded solutions to any problem. And, they are design tools to guide the process of designing software. Implementation details are outside the scope of design patterns.
Generally, I find that these work well with the Provolone and SandwichOil patterns. lol

Design pattern for swind application development

Hello all,
I am trying to develop a new swings application with the centralized database connectivity for the data transaction .Any one please tell me which design pattern is mostly suitable for the GUI application development using swings .
Thanks in advance
sowjanya

Pu - this is your decision.
In order to know which design patterns are suitable for you, you should know what the design pattern do.
So I suggest to read about design patterns:
http://en.wikipedia.org/wiki/Design_pattern_(computer_science)
Note also that ther exists a framework called Spring.
Greetings
Thorsten

What are the best practices in design patterns?

What design patterns are likely popular?

If you go to your local bookstore or online book store you will find at least 20 books that describe this.
Some how I doubt you are going to get 20 books worth of an answer.

What is the best design pattern for this problem?

No code to go with the question. I am trying to settle on the best design pattern for the problem before I code. I want to use an Object Oriented approach.
I have included a basic UML diagram of what I was thinking so far.
Stated simply, I have three devices; Module, Wired Modem, and Wireless Modem.
In the Device Under Test parent class, I have put the attributes that are variable from device to device, but common to all of them.
In the child classes, I have put the attributes that are not variable to each copy of that device. The attributes are common across device types. I was planning to use controls in the class definition that have the data set to a default value, since it doesn't change for each serial number of that device. For example, a Module will always have a Device Type ID of 1. These values are used to query the database.
An example query would be [DHR].[GetDeviceActiveVersions] '39288', 1, '4/26/2012 12:18:52 PM'
The '1' is the device type ID, the 39288 is the serial number, and the return would be "A000" or "S002", for example.
So, I would be pulling the Serial Number and Device Type ID from the Device Under Test parent and child, and passing them to the Database using a SQL string stored in the control of the Active Versions child class of Database.
The overall idea is that the same data is used to send multiple queries to the database and receiving back various data that I then evaluate for pass of fail, and for date order.
What I can't settle on is the approach. Should it be a Strategy pattern, A Chain of Command pattern, a Decorator pattern or something else.
Ideas?

elrathia wrote:
Hi Ben,
I haven't much idea of how override works and when you would use it and why. I'm the newest of the new here.
Good. At least you will not be smaking with a OPPer dOOPer hammer if I make some gramatical mistake.
You may want to look at this thread in the BreakPoint where i trie to help Cory get a handle on Dynamic Dispatching with an example of two classes that inherit from a common parent and invoke Over-ride VIs to do the same thing but with wildly varying results.
The example uses a Class of "Numeric" and a sibling class "Text" and the both implement an Add method.
It is dirt simple and Cory did a decent job of explaining it.
It just be the motivation you are looking for.
have fun!
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

What are patterns in BPM

hi
experts
What are patterns in BPM

Hi
BPM Patterns are designed by SAP by considering the frequent requirement.these patterns can be reused in the similar requirement rather than the developer designing it from the scratch....and you can find the patterns under SAP BASIS Software Component...
The following websites containing PDF & PPT documents BPM Patterns which will answer u'r question in detail with examples:
http://www.sap.com/platform/netweaver/pdf/BWP_NetWeaver_BPM.pdf
BPM Process Patterns Repeatable Designs for BPM Process Models
http://edocs.bea.com/albsi/docs55/pdfs/BPM%20Process%20Patterns%20White%20Paper.pdf
An introduction to Business Process Management
http://www.avelon.nl/downloads/Introduction_BPM.pdf
Business Process Management -Modeling to Execution
http://www30.sap.com/korea/company/events/techday05/img/data_06.pdf
BUSINESS PROCESS MANAGEMENT (BPM)
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/ed49db90-0201-0010-c4a5-c520866a19c7
BPM Process Patterns:Repeatable Design for BPM Process Models
http://www.bptrends.com/publicationfiles/05%2D06%2DWP%2DBPMProcessPatterns%2DAtwood1%2Epdf
Also these blogs will be helpfull
Walkthrough with BPM
XPath to show the path (Multiple Receivers)
RFC Scenario using BPM --Starter Kit
/people/sravya.talanki2/blog/2005/08/24/do-you-like-to-understand-147correlation148-in-xi
The specified item was not found.
Illustration of Multi-Mapping and Message Split using BPM in SAP Exchange Infrastructure
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/media/uuid/daea5871-0701-0010-12aa-c3a0c6d54e02
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/media/uuid/e8515171-0701-0010-be98-e37bec4706cc
BPM:Single Sender and Multiple Receivers based on synchronous exchange(switch) part-1
Using a BPM to collect messages for a set interval of time
Thanks
Saiyog

Are there any Client/Server Application (using sockets) design patterns?

Hi,
The title of the post nearly says it all. I am searching for different design patterns related with the development of a client/server application. I understand that there must be any different ways on how a client/server application can be developed.
Regards,
Sim085
Disclaimer:
When I enter in the Socket forum on this site I recieve this message "Thank you for any participation in this forum. Due to a lack of relevant activity, we have decided to archive this forum on June 16, 2006. For future posts on this topic, we suggest you use the Networking forum" and I am not allowed to create a new post! However I can see posts done yesterday! All i did is add the forum in 'my forums'. Does this happen to you people as well?

Hi Sim085...How are you?
So look this:
http://forum.java.sun.com/thread.jspa?threadID=5148926&tstart=75
I don�t know if is what you want...but I hope in this^^
Ok man...If you have one example for help you is better.
[ ]

What is a design pattern?

Howdy,
I hear a lot of talk of deasign patterns in ABAP...
My question is what on earth is a design pattern and why/how would it be useful?
Any ideas anyone

Hi Steve.
The good point to start with design patterns is to read book "Design Patterns - Elements of Reusable Object-Oriented Software" by Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides. It gives strong, consistent understanding of patterns basis with real life examples.
Short introduction extract:
"Christopher Alexander says, "Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice". Even though Alexander was talking about patterns in buildings and towns, what he says is true about object-oriented design patterns. Our solutions are expressed in terms of objects and interfaces instead of walls and doors, but at the core of both kinds of patterns is a solution to a problem in a context.
In general, a pattern has four essential elements:
The pattern name is a handle we can use to describe a design problem, its solutions, and consequences in a word or two. Naming a pattern immediately increases our design vocabulary. It lets us design at a higher level of abstraction. Having a vocabulary for patterns lets us talk about them with our colleagues, in our documentation, and even to ourselves. It makes it easier to think about designs and to communicate them and their trade-offs to others. Finding good names has been one of the hardest parts of developing our catalog.
The problem describes when to apply the pattern. It explains the problem and its context. It might describe specific design problems such as how to represent algorithms as objects. It might describe class or object structures that are symptomatic of an inflexible design. Sometimes the problem will include a list of conditions that must be met before it makes sense to apply the pattern.
The solution describes the elements that make up the design, their relationships, responsibilities, and collaborations. The solution doesn't describe a particular concrete design or implementation, because a pattern is like a template that can be applied in many different situations. Instead, the pattern provides an abstract description of a design problem and how a general arrangement of elements (classes and objects in our case) solves it.
The consequences are the results and trade-offs of applying the pattern. Though consequences are often unvoiced when we describe design decisions, they are critical for evaluating design alternatives and for understanding the costs and benefits of applying the pattern. The consequences for software often concern space and time trade-offs. They may address language and implementation issues as well. Since reuse is often a factor in object-oriented design, the consequences of a pattern include its impact on a system's flexibility, extensibility, or portability. Listing these consequences explicitly helps you understand and evaluate them."
Regards,
Maxim.

What is recommended / preferred design pattern for Swing?

I have been confused by the apparent variety of design patterns used when putting together a Swing GUI application. For example, one pattern does this:
public class myclass extends JFrame {
myclass() {
// do all the stuff here
public static void main(String args[]) {
// instantiate class here
while another pattern goes like this:
public class myclass extends JFrame {
myclass() {
super("title");
public static void main(String args[]) {
// do all the stuff here
Is there a preferred way to do this stuff, or is it a matter of personal preference?

Hi
I txnk there are no choice : the only valid aproach is (1)
because :
main is a "know" entry point just for instantiate some classes
the event thread is alive after main is completed, so your app have a GUI elements who responds to some events via some classes (the listeners for these events).
Of course you can add listeners at main level but, what hapen if
you need these GUI in other app (the main func is only called when you invoke the JVM to an start class)
Normally the JFrame have some member funct or some internals classes to respond some events (at this point there are some alternatives)
Hope this help
Bye

[BOOK] What's the best book about DESIGN PATTERN

Hi Guys,
by experience, what's the best book for you concerning the Design Pattern in Abap. I mean :
Quality,
Comprehensiveness,
Clearness,
Amount of chapter,
etc.
Thank for advices.
Rachid.

Dear Rachid,
This is rank 1 book, but u have learn online also. So many websites are there. example search: OO Design patterns ZEVOLVING.
Regards,
Abbas.

Suggest what design pattern is applicable for my case

I have an object called GrantAward , these awards I have to show to the user for selection
1. I call a web service to get list of GrantAwards.
2.for each GrantAward check if this is present in my database
a. if not there insert
3.for each GrantAward check some conditions
a if satisfied add to the list to show to user
b if not satisfied do not add to list .
these are the steps involved before I can show the GrantAwards to user for selection , please suggest me what design pattern can I use ?

I'm not sure you want to hunt for patterns when you already know what you are implementing. A lot of people have pattern fever. Patterns are useful constructs for communicating design ideas and enforcing best practices. But I rarely go out and hunt for a specific pattern (or name my objects after patterns). If you are doing a heavyweight methodology with RUP or something similar, I could see stereotyping your UML with patterns.
That having been said, you already have a Facade with your service. You are undoubtedly using DataAccessObject to fetch your records. Your conditions could be implemented with a ChainOfResponsibility and/or Strategy pattern. What you return could be a Composite. Potentially the request and response are a Command. And your overall architecture could be MVC.
But IMO that is overkill.
- Saish

[DESIGN PATTERN] Factory: Define Method Area

Hi Guys,
I have a question regarding the Design Pattern:Factory. According my need the question is below as:
I have the Abstract Class AAA with it own Abstract method that create objects (only one method).
I have a Final Sub-Class BBB with 20 instantiate methods + the inherited method from Class AAA.
BBB->method_bbb1().
BBB->method_bbb2().
BBB->method_bbb3().
I have a Final Sub-Class CCC with 10 instantiate methods + the inherited method from Class AAA.
CCC->method_ccc1().
CCC->method_ccc2().
CCC->method_ccc3().
Afterwards:
Class BBB is instantiated through the Factory. The TYPE of BBB is AAA.
Class CCC is instantiated through the Factory. The TYPE of CCC is AAA.
My question is:
How could I use the 20 methods of BBB without to declare them in AAA (without inheritance). Because, if I declare them in AAA, consequently they will be visible in CCC. And I don't want to ...
DATA BBB TYPE REF TO AAA. "Var Object BBB is type of Class AAA
DATA CCC TYPE REF TO AAA. "Var Object CCC is type of Class AAA
BBB = AAA=>Factory( 'BBB' ).
CCC = AAA=>Factory( 'CCC' ).
" I want to call, in that way:
BBB->method_bbb1().
CCC->method_ccc1().
CCC->method_bbb1(). " RAISE ERROR
I have found a way but I don't know if it's breaking the rules of the Factory Concept.
Have you got any idea?
Thank you in advance.
Rachid.

Hi,
If you have declared the methods in abstract class as protected or public and if you are inheriting it to the sub classes, then the methods will be available in the subclasses. There is no way to restrict like few abstract methods needs to be inherited and others need not be inherited. The inherited classes are forced to implement the abstract methods.
In your scenario, i do not think there is a need of abstract class, as I assume that both of your classes does some stand alone logic( as per your question ) compared to the other and doesn't have any common operations. Could you please let us know about this in detail ?? What about INTERFACES ?, Please have a look into it.
Kesav

What are design patterns ?

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