Designer pattern allows to develop complicated object phase by phase and also makes sure a way to develop an object as a finished object. Construction of object should be such that same development procedure can make different representations.Director manages from the of object and only home knows what type of mind make.




Designer style design in Java is a creational style i.e. used to create things, similar to manufacturer method style design which is also creational style design. Before studying any style design it cab be recommended that find out the issue a particular style design resolves. Its been well said requirement is the mom on innovation. Studying design without experiencing issue is not that effective, instead if you have already experienced problems than its much easier to understand style design and learn how it is to fix the issue. In this Java design guide we will first see what issue Designer style design resolves which will give some understanding on when to use builder style design in Java, which is also a popular style design.




For example, You can consider publishing of a guide.Printing of a guide includes various actions such as publishing desk of material,preface,introduction,chapters and summary. Finally you will get complete guide object. With the help of same procedure,you can create guides with different qualities.



Elements:




Builder


identifies an subjective interface for creating areas of a object object.


ConcreteBuilder


constructs and puts together areas of the object by implementing the builder interface.


describes and keeps track of the reflection it makes.


provides an interface for accessing the object.


Director


constructs an object using builder interface.


Product


represents the complicated object being built.ConcreteBuilder builds the object's internal reflection and describes the procedure by which it is constructed.


includes classes that define the component areas,including interfaces for the assembling the areas into outcome.




When to use it:




Object development methods should be independent of system.


New development algorithm can be added without changing core code.


The development procedure must allow different representations for the object that' s contructed.


Playback control over development procedure is required.




WorkFlow:




The client makes the home object and configures it with the desired builder object.


Director notifies builder whenever a part of object should be built.


Designer handles requests from the home and adds areas to the object.


The clients retrieves the object from builder.




Example:


You can consider priniting of a guide.Printing of a guide includes various actions such as publishing desk of material,preface,introduction,chapters and summary.Finally you will get finish guide object. With the help of same above procedure,you can write guides with different qualities. BookWriter will instruct bookBuilder to create guide in actions and return last guide object.




Designer style design in Java – Benefits and Cons


Live everything Designer style also has some drawbacks, but if you look at below, benefits clearly exceed drawbacks of Designer style design. Any way here are few benefits and drawback of Designer style design for creating things in Java.




Advantages:


1) more maintainable if variety of areas needed to make object is more than 4 or 5.


2) less error-prone as user will know what they are moving because of precise method call.


3) more effective as only fully designed object will be available to customer.




Disadvantages:


1) verbose and program code replication as Designer needs to duplicate all areas from Unique or object category.




When to use Designer Style in Java


Builder Style is a creational style and should be used when variety of parameter needed in constructor is more than controllable usually 4 or at most 5. Don't mix up with Designer and Manufacturer style there is an apparent difference between Designer and Manufacturer style, as Manufacturer can be used to make different execution of same user interface but Designer is linked up with its Package category and only profits object of External category.




That's all on Designer style design in Java. we have seen why we need Designer style , what problem it resolves, Example of builder style design in Java and finally when to use Designer patter with benefits and drawbacks. So if you are not using telescopic constructor style or have a choice not to use it than Designer style is way to go. You can join the Java certification course in Pune to make your career in this field.