What is mediator in Design pattern.

hi what is mediator in Design pattern.
How can i use it. any source code available ???

you're exactly the target audience for the java desktop !!!
http://java.sun.com/javase/technologies/desktop/
cheers!

Similar Messages

What is the best design pattern for top-down ws development..?

Hi,
What is the best design pattern for top-down development+ wsdl2service....?

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 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 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

What is the best design pattern for multiple instruments?

I have several PXI cards (DMM, O-scope, etc) that I want to create a master panel that can control all of the instruments individually, though not necessarily all at the same time (turn "instruments" on and off at will while the master vi continues to run). Is there one design pattern (master/slave, producer/consumer, etc.) that works better than another for this type of master panel? Are there other alternatives for this type of problem (VI Server, etc)?
I was hoping that I could save a bunch of time if I could start on the right path right off the bat!
Thanks,
-Warren

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

Location manager design pattern?

What is the best design pattern for using the location manager with intermittent but time-sensitive use? My app records location each time the user creates a photo, creates a note, records audio, etc and stores it using CoreData. The problem is the location manager has to spin for a bit to get the best reading, and in that time the user could easily have navigated the UI to delete the object they've created and create a new one. In that case I'd want to interrupt any location services active for the deleted object.
Is a singleton the best pattern, keeping the active objects in an array and using @synchronize(object)...but running each in a different thread?
Or assigning the location manager as a transient property of the object and calling stopUpdatingLocation if it gets deleted?
Any thoughts? TIA...

I created a singleton for this - seems to work quite well

Common Design Patterns For Webservices

Hi All,
I am creating a webservice which generate the result by iterating multiple webservices serially(Workflow) or parallel(Aggregator).
What are the common Design patterns I can apply here ? Currently my application flow is
WebserviceEndpoint-> WebserviceDelegate(POJO) -> Helper Classes ->Aggregator/Workflow Impl which uses WSClients(JAX-WS Stub)
Do we need to maintain separate DTO for passing Request to the Inner layers ?
Please share your comments.
Thanks,
Paul

Thanks for your valuable time
I have 3 Webservices A(Provider),B,C. Service 'A' is a consumer of service 'B' and 'C'.
A - is exposed to Consumers, A act as a proxy layer for service B and abstract 'C' from users ,Service 'A' only do the service orchestration .Service 'A' using data from Service 'B' and 'C'
B – is of same specification as that of Service A (Service B contains All operation defined on A +Internal operation for service A).Internal Webservice which act as active datasource.Request and response structure is same as that of Service 'A'.
C – is different external service ,requests for Invoking Service 'C' need to be generated from Consumer Request and operations exposed in Service 'B'. External Webservice act as active Data source. Enrich the service 'B' output using service 'C' ,This is done by Service 'A'
I have done this using following components.
WebserviceEndpoint-> WebserviceFacade(POJO) -> Helper Classes ->Aggregator/Workflow Impl which uses WSClients(JAX-WS Stub)
It will be great If some of you can suggest a good logical separation for Service 'A' ? Is above logical separation is correct?
Thanks,
Paul

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 CLD

What is the best design pattern to pass the CLD?
I think that the "producer/consumer" is not the best way because it need more time..
A simple "state machine" is more fast.
Solved!
Go to Solution.

State Machine with the capability to handle events from the user and timing. That will handle all of the scenarios I have seen.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Design pattern for unprotecting and reprotecting sheets with VBA?

Many macros can't run when a worksheet is protected, so when I develop an Excel workbook that has protected worksheets, I have to unprotect worksheets when macros are called and then reprotect the worksheets once the macro has completed.
The current design pattern I use for this is the following:
I look at each procedure individually and consider which sheets need to be unprotected for it to run. Then in each procedure I write:
Sub Test()
Dim bSheet1Protected as boolean
Dim bSheet2Protected as boolean
bSheet1Protected = Sheet1.ProtectContents
bSheet2Protected = Sheet1.ProtectContents
bSheet1Protected.Unprotect
bSheet2Protected.Unprotect
'''The rest of my code
if bSheet1Protected then Sheet1.Protect
if bSheet2Protected then Sheet2.Protect
End Sub
But I imagine that maybe there are better ways of doing this. What is your preferred design pattern for unprotecting and reprotecting sheets with VBA?

Hi JP3O,
I think it is a good practice to unprotect the worksheet before execute some code and protect it back after the code execute finished.
>>But I imagine that maybe there are better ways of doing this. What is your preferred design pattern for unprotecting and reprotecting sheets with VBA?<<
I am not able to find a better way since we always need to unproect the worksheet if some code didn't not executed successful when the worksheet is proected.
Regards & Fei
We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
Click
HERE to participate the survey.

Flex design pattern for BlazeDS transfer objects

Dear Community,
I have a question regarding the nature of objects transferd from BlazeDS backend to the Flex client.
According to some adobe docs all the presentation logic should be in flex and BlazeDS should provide only services.
The question is what kind of transfer objects should be used? with what level of abstraction?
To make it more clear let's talk about a simple forum application like adobe forums.
I have created a Forum service, which returns a Forum transfer object, which has a List of Threads, with each thread having a List of Messages.
Flex gets the Forum transfer object and does all the presentaiton work.
This is a very nice seperatin of concerns architecture BUT there are two major performance issues:
- when the forum becomes bigger the transfer object will be huge
- the flex will use huge client resources to create the presentation of the forum transfer object.
So my question is what is your strategy/ design pattern for such a problem.
An obvious answer would be create services that include the presentation logic and use transfor objects like ThreadListPage which will include only the first 10 threads.
Thanks in advance

I think you are going to get a few varied types of answers to a general question like this, but I will comment on a few things. First, you should only be transmitting the data that you need to use or display to the user at the time. If this forum was implemented in Flex (I wish) you wouldn't transfer the text for all the threads. You might not transfer the thread text at all (just the subjects), you'd make calls back to the server to fetch that data when and if you need it.
Also, I think you are overestimating the resources required for the Flex "presentation layer". If you think about it, these workstations we have here are pretty idle most of the time when you're at a website. Nowadays there's plenty of processing power just sitting there waiting, so as long as your design isn't flawed the CPU or memory are rarely going to be a bottleneck with Flex.
The way I design, BlazeDS (or GraniteDS etc) should mostly just be "serving data". There is some flexibility available, for example I don't see a problem with putting certain types of business rules (such as a limit on the number of results that can be recieved in a search) within server side code, and validation rules on the Flex side. So there's not too many "industry standards" in Flex yet beyond maybe what's done in the various standard architectures, at least not that I'm aware of.
You might find it beneficial to look into some of the various frameworks/architectures available like Cairngorm, Mate, Swiz, and so on. Learning how they work (looking at examples) would probably answer some of your questions too.

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 command design pattern? what is the problem that it solves?

Hi i have been reading few articles on command design pattern but was unable to understand what it is and what problem does it solve. As far as my understanding goes if there is a pre specified method in an object that could execute and perform the necessary activities then it is called as command design pattern. Why is it named as command design pattern, it is because in a shell we use commands to retrieve output. For example when we type "dir" in dos command prompt it returns the list of files. so here we have to remember a preexisting exe file named "dir" which does something when used. So here like we call it command because when "dir" is passed to the computers it returns something that is expected. may be the computer obeys the command issued and return something back. So like wise if there is a method that is defined as as the command, for example in struts framework the action class must have a method "execute()" which is called by the framework to execute the necessary action mapped to it. So if there is a predefined method like "execute" in struts then the object is said to be followed command design pattern. So what actually does it solve?
What ever i have written is my understanding from the articles i have read about the design pattern. So kindly correct me if i am wrong. Help me understanding what actual problem does this pattern solves. Thanking you in advance.

This is really off-topic for these forums. You might do better on StackOverflow.com. I'll just say that although the first Design Patterns book came as a revelation to me, it was more for (a) the nomenclature (decorator, factory, facade, etc) which is still with us and (b) about five of the original patterns, which told me things I didn't already know. I've never used any of the others, including Command, and the whole design patterns thing quickly degenerated into farce with what seemed like a sustained attempt to reduce the whole of computer science to design patterns, which really isn't the point. As an example, there is one in another book called Type Object, which is nothing but 3rd normal form, which can be defined roughly in a couple of sentences. This pattern went on for dozens of pages with a very artificial example. I wrote to the mailing list about it: 'Type Object considered hilarious'. I got a rude reply from the original author, which I guess I expected, but also an incredible response from the list owner, saying I should recast my objections in the form of a design pattern. That lost it for me. True story. Moral: don't take this religion, or any IT religion, too seriously. They come around every 18 months or so with the regularity of the next bit of Moore's Law. I've seen dozens of them come and go since 1971, all with something to say, all 90% nonsense.
See here for a longer version of this incident.

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.

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 mediator in Design pattern.

Similar Messages

Maybe you are looking for