JavaRanch OO, Patterns, UML and Refactoring

Has - a , Is - a

Fri, 9 May 2008 04:12:58 MDT

whath are the meanings of Has - a and Is - a

would you find it?

Strategy & Dependency Injection

Thu, 8 May 2008 21:26:57 MDT

Problem Description

I have 2 types of web artifacts, Image and Flash.
And their serialization format is different depending on the chosen format.

I am working within a dependency injection framework and I want to know
how to use the Strategy pattern in conjunction with it.

code:


// initial design
abstract class Artifact
{
 enum FORMAT { JSON, XML }
 void serializeTo( OutputStream out, FORMAT format );
}
 
class Image extends Artifact
{
 public serializeTo( OutputStream out, FORMAT format )
 {
 switch( format )
 {
 case XML:
 ...
 case JSON:
 ...

Large Scale Refactoring

Tue, 6 May 2008 13:14:50 MDT

I have a rather large scale refactoring problem to solve, and I am looking for advice on where to start.

The J2EE applications that we support are about 10 years old now, and they have been sadly neglected. The original designers tried to build an enterprise framework to support 8 enterprise applications. The result is that all 8 applications are now tightly bound to the old technology. There's really old Log4J (with assert), very early Struts (with enum), and it all runs at Java 1.3 compliance levels. The problem is as soon as you try to upgrade one piece of the puzzle, you break all the other pieces.

The problem is compounded by the way the source code is managed. The shared libraries are included in each Ja...

File Conversion

Sat, 3 May 2008 03:24:30 MDT

Hi,
I have an XML file A with some structure. I have a program that uses Castor to read file A and converts it into Java Objects.
Now I need to convert file A into another XML file say B with some different structure. What I have thought is to define an interface which will have methods that would return me objects pertaining to XML file B and then use an Adapter class that would implement this interface and invoke and fetch values from the existing class(that returns objects of file A).
The client to the adapter will then marshall these objects using Castor that would give me xml file B.
Why I plan to do this is because I have more such XML files with some different structures that needs to be converted to structure of...

Patterns to help solve the folksonomy tagging problem

Tue, 29 Apr 2008 21:00:20 MDT

I'm trying to model the way how del.icio.us handles their storage for the tags for a link.

Obviously tags need to be a dynamic property (referring to http://www.martinfowler.com/apsupp/properties.pdf). (http://www.martinfowler.com/apsupp/properties.pdf%29.) Any more inspirational ideas ? Thanks.

UML Class Diagrams

Tue, 29 Apr 2008 03:44:18 MDT

Hi,

I intend to make class diagrams for an existing database set up.I have RAD 6 as an IDE/tool. Any pointers for the above situation?

Mapping between Business deigate and Service locator

Tue, 29 Apr 2008 00:34:17 MDT

Hi All,

We know that Business deligate can make use of service locator.
Can one Business deligate can make use of multile service locators? or it should use only one sevice locator?

What is the mapping between Business Deligate and service locator?

waiting for your reply...

Design Patterns...

Mon, 28 Apr 2008 23:32:17 MDT

Hi all,

I have just started to study Desgin Patterns. I am using Head First by K&B.
I am at Factory design pattern.

My problem is , i am confused with the decorator and factory.someone said me to identify the pattern for a flow , and i got confused with decorator and factory.

code:

 
 inteface{method();}
 |
 ^
 class1 implements interface
 class2 implements interface
class3{
 Interface i = class1;
 i.method();
}

can someone help me to idenfity whether it has decorator or factory pattern.
cause i read somewhere factory pattern says -Define an interface for creating an...

Sharing across MVC

Sun, 27 Apr 2008 11:48:12 MDT

I'm writing a program to collect and display currency prices. This is my first attempt at developing to the Model-View-Controller design pattern.

My question: how to design the structure of the program so that common objects and design elements are available to the model, the view and the controller.

For example, I want to create a 'properties' object that will contain all of the properties of my program. Some of these properties will be accessed by the model code, some by the view and some by the controller.

Isn't having a single properties file/object breaking the independance of the M V and C? Should I think about having 3 separate properties files? After all, if I want to replace the View with another...

about a very BIG confusion in design pattern.

Wed, 23 Apr 2008 19:02:01 MDT

I should not post this here but I dont know where to post it exactly .

I am asking about design patterns . In some website I see design patterns means : Factory Pattern
Abstract Factory Pattern
Singleton Pattern
Builder Pattern
Prototype Pattern
Structural Patterns
Adapter Pattern
Bridge Pattern
Composite Pattern
Decorator Pattern
Facade Pattern
Flyweight Pattern
Proxy Pattern
Behavioral Patterns
Chain of Responsibility
Pattern
Command Pattern
Interpreter Pattern
Iterator Pattern
Mediator Pattern
Momento Pattern
Observer Pattern
State Pattern
Strategy Pattern
Template Patte...

Anti-patterns - Singleton.

Wed, 23 Apr 2008 08:23:59 MDT

Anyone have any thoughts on singleton being an antipattern -- esp in context of using it with the Factory Pattern.
Are there any disadv -- to make the Factory a singleton?

Which Pattern to select ?

Wed, 23 Apr 2008 01:21:59 MDT

Consider my case and tell me which pattern will be a good solution.

I have one entity called EntityA

which is consist of Section A , B , C , D , E.

Under the dynamic cases these sections will be included, for example

Case 1
Entity 1 consist of Section A , C, D, E.

Case 2

Entity 1 consist of Section A , B , C, D, E.

..etc

In each section i have many fields to fill and i have to do the following operations

1) validate each sections

2) save the data for the each sections.

Dynamic attribute selection for Excel export

Mon, 21 Apr 2008 09:30:17 MDT

Hi,

I'm to refactor a web application that makes heavy use of good(?) old JDBC calls to persist and retrieve data from an Oracle DB. The application features something called "Excel export" where users can select attributes to be exported. The generated Excel sheet has very simple looks, it's really nothing more than a table.

The mechanism I'm worried about is not the Excel sheet at first hand but the way how selecting wanted or unwanted attributes works: the user selects more or less directly column names from a DB view that contains all the data in question, his selections are concatenated to plain SQL and executed. The user doesn't know what really happens in the background, of course. Apart from the attributes/c...

Soa Architecture Design

Fri, 18 Apr 2008 09:00:21 MDT

Hello Guy's
Where i work, we use Spring / CXF to create webservice.

How we procede for the analyse is :
1) Design in Enterprise Architect
2) Document it textual in a wiki
3) Code.

But we talking about services here.
I am not agree with enter the code in a wiki because its a lot of loosing time.

We had to view the service tree with all fuctions very quickly when we developed a facade service or an front-end application.

With the wiki approch , we had to navigate in pages for each services and I think this is not a good thing.

Do you have some suggestion to how doing the UML / Diagram of class / and view all services in a simple way ...

don't know how to handle different params in a command.

Wed, 16 Apr 2008 12:19:02 MDT

Hi

I have an engine that can be turned on and has a hub something can attached to (a gear box maybe - I'm not a mechanic so please don't laugh).
As a matter of fact - the hub the engine has is shipped along with the engine so it's also a third party thing.

code:


class Engine {
 
 public void turnOn() {
 // applicable code
 }
 public Hub getHub() { 
 // applicable code
 }
 
 // ... some other methods ...
}

These are just two features that I'm using right now - but there's more. The thing is that I'm not making engines - I'm just a user - so there may be som...

don't know how to handle different params in a command.

Wed, 16 Apr 2008 09:39:01 MDT

code:


class Engine {
 
 public void turnOn() {
 // applicable code
 }
 public Hub getHub() { 
 // applicable code
 }
 
 // ... some other methods ...
}

These are just two features that I'm using right now - but there's more. The thing is that I'm not making engines - I'm just a user - so there may be som...

don't know how to handle different params in a command.

Wed, 16 Apr 2008 05:47:01 MDT

code:


class Engine {
 
 public void turnOn() {
 // applicable code
 }
 public Hub getHub() { 
 // applicable code
 }
 
 // ... some other methods ...
}

These are just two features that I'm using right now - but there's more. The thing is that I'm not making engines - I'm just a user - so there may be som...

how to design a website?

Tue, 15 Apr 2008 18:21:00 MDT

What is the best way to design a website? I mean which design methodology would one use.

how to design a website?

Tue, 15 Apr 2008 16:18:59 MDT

What is the best way to design a website? I mean which design methodology would one use.

packages in component diagrams

Mon, 14 Apr 2008 13:01:18 MDT

I have seen, in many places, packages in component diagrams. Most commonly as a "subsystem". What does this packaging mean - do we use packages to show physical distribution of components or logical? should these packages be reflective of "tiers". any ideas?

how do we represent an external system, is the "subsystem" package stereotype valid for that?

don't know how to handle different params in a command.

Mon, 14 Apr 2008 09:57:17 MDT

code:


class Engine {
 
 public void turnOn() {
 // applicable code
 }
 public Hub getHub() { 
 // applicable code
 }
 
 // ... some other methods ...
}

These are just two features that I'm using right now - but there's more. The thing is that I'm not making engines - I'm just a user - so there may be som...